1/**@page RN9 Release notes for SCIP 9
3@section RN911 SCIP 9.1.1
4*************************
9- fix bug in separator aggregation that caused incorrect terminations when for an integral objective the objective limit was set to a fractional value
10- fix bug in memory management of doublelex matrices where indices were set beyond array bounds
11- store relevance flags in consdataTightenCoefs() of cons_linear.c to avoid dropping variables unintentionally due to numerical changes
12- fix possible segmentation fault when resetting local and global bounds of original variables after abnormal termination
13- compare coefficient scales to detect parallelism to avoid integral relaxations in detectRedundantConstraints() of cons_linear.c
14- remove coefficient information from linear constraint hashes in order to compare keys with tolerances
15- fixed NULL pointer dereference in SCIPtpiGetNumThreads() of TinyCThread interface if called before SCIPtpiInit(); now returns 0 in this case
16- calling SCIPsolveConcurrent() when SCIP was compiled without a TPI now results in a plugin-not-found error
17- fixed LPI status functions of lpi_cpx if the barrier is called
18- check cuts for redundancy after scaling in cutTightenCoefs() and cutTightenCoefsQuad() of cuts.c
19- maintain definition of artificial integral variables in xor constraints to avoid invalidation of conflict constraints
20- free childless nodes only after the deactivation of the old focus path in treeSwitchPath() of tree.c
21- only normalize rows for column norm evaluations in shift-and-propagate heuristic to avoid unscaled violations
22- expression handler for absolute value computes now also a cut when one of the bounds is infinite as long as the sign of the argument is known
23- check for more data to be freed before modifying nonlinear constraints in SCIPaddExprNonlinear()
24- allow for terms with zero coefficients when checking sum in SCIPexprCheckQuadratic()
25- do not abort writing of constraints to lp/pip files (and forget to free buffer memory) when encountering unsupported nonlinear constraint
26- fixed that strings with names and descriptions of the LPI's were not null-terminated
27- fixed decision on when to enforce nonlinear constraints on relaxation solutions if integer variables are present
28- fixed reading of very long lines (>78000 characters) in FlatZinc reader
29- fixed write of strings with at least 1024 characters when compiling with MSVS 2015 (14.0) or later (still an issue with earlier MSVS, which will not be fixed)
30- keep epsilon coefficients in applyFixings() of cons_linear.c until multiples are merged to avoid loss of relevant contributions
31- fixed that some variable type changes were not accounted correctly in presolve of linear constraints
32- fix constraint sorting in setpp-orbitope upgrade in symmetry code
33- fixed that SCIPnodeGetConsProps() also counted bound changes from propagators
34- use original and-constraints of an untransformed pseudoboolean constraint when copying original problems to avert segmentation faults
35- sort and-constraints of a pseudoboolean constraint with respect to the resultant problem indices to avoid shuffled copies
36- treat pseudoboolean constraints as nonlinear constraints in OPB reader to prevent duplication mistakes
38Examples and applications
39-------------------------
41- Binpacking example: implement Farkas pricing for packings because branching can actually lead to infeasible restricted master LPs
46- allow unknown parameters to let tests pass if only optional dependencies are missing
53- fixed compilation and linking with HiGHS; to use HiGHS, cmake now requires to specify the directory containing the `highs-config.cmake` file via `-DHIGHS_DIR`
54- extended identification of Ipopt library on Windows to also look for ipopt.dll.lib, as this is used since Ipopt 3.13.0 (2019)
59- recent changes in HiGHS can lead to errors when using HiGHS as LP solver under SCIP (https://github.com/scipopt/scip/issues/102)
62@section RN910 SCIP 9.1.0
63*************************
68- added constraint handler that checks and enforces bounds on original variables which have been fixed or aggregated in the transformed problem
69- allow for implicit integer variables in xor constraints
70- implemented symmetry detection callbacks for pseudoboolean constraints
71- added option to consider enforcement of nonlinear constraints (including spatial branching) before integrality has been enforced
76- make sure that, in dual proof analysis, upgraded constraints can report their number of variables
77- check knapsack constraints as linear constraints to avoid violations based on implicit integrality
78- make sure that symmetry detection callbacks report success
79- make arithmetics in cuts.c more robust to avoid invalid scg cuts due to numerical rounding sensitivity
80- allow to copy pseudoboolean constraints even if no AND constraints are present in order to avoid a warning
81- set value for variable that is introduced to reformulate nonlinear objective function when reading .nl files with initial solution
82- fixed that multi-aggregations from PaPILO were accepted without ensuring that their bounds hold
84Examples and applications
85-------------------------
87- TSP: removed `gzstream.h/hpp` and parse gzipped files differently
94- SCIP_DECL_NLHDLRENFO takes additional parameter branchcandonly to indicate whether only branching candidates should be registered,
95 without looking for cuts or boundchanges
99- new function SCIPgetExprActivityNonlinear() to get activity of nonlinear constraint
100- new function SCIPincludeConshdlrFixedvar() to include new constraint handler that checks bounds on fixed original variables
104- limits/primal to terminate the solve as soon as the primal bound is at least as good as this value, same as limits/objectivestop (deprecated)
105- limits/dual to terminate the solve as soon as the dual bound is at least as good as this value
106- presolving/milp/internalmaxrounds to control the maximal rounds for each call of the milp presolver (PaPILO)
107- constraints/fixedvar/∗ to control the new constraint handler that checks bounds on fixed original variables
108- constraints/nonlinear/branching/mixfractional to specify minimal average pseudo cost count for discrete variables
109 at which to start considering spatial branching before branching on fractional integer variables
110 (default infinity means that integrality is always enforced before nonlinear constraints)
111- constraints/nonlinear/branching/fracweight to specify weight of fractionality of integer variables in spatial branching
113### New data structures
115- enum SCIP_Status has been extended by SCIP_STATUS_PRIMALLIMIT and SCIP_STATUS_DUALLIMIT to indicate termination at limits/primal and limits/dual respectively
120- changed the default symmetry computation package from sassy+bliss to sassy+nauty
121- bliss source is no longer included in the source tree, but can be linked as external library (https://github.com/ds4dm/Bliss)
122- cmake now automatically downloads and installs the latest release version of SoPlex from GitHub if it is not found directly
127- updated nauty to version 2.8.8
130@section RN901 SCIP 9.0.1
131*************************
136- fixed bug in detection of double lex matrices due to wrong memory allocation
137- fixed bug where parameter `limits/objectivestop` was copied to subscips in plugins which have different objectives
138- in count mode respect empty solution when problem is solved in presolving
139- fixed that SCIP may have tried to pass a negative random seed to an LP solver
140- fixed bug where conflict analysis in strong branching tried to analyze an unsuccessful LP solve
141- enable parameter limits/restarts by allowing to reach the restart limit in restartAllowed()
142- handle normalizing linear constraints in presolving with more caution to avoid numerical difficulties for integer variables with large coefficients
143- use quad precision to calculate residual activity bounds to reduce numerical errors for large variable bounds in cons_linear.c
144- in SCIPsolveProbingLP() when objective has been changed do not return cutoff due to exceeding the cutoff bound
145- set probing LP to be a relaxation only when objective has not been changed
146- declare contradicting infinities in getMinActivity() and getMaxActivity() as non-tight
147- reject farkas solution with large values to bound magnification of errors in SCIPgetFarkasProof()
148- if all variables are fixed, apply relative feasibility tolerance to avoid invalid infeasibility in applyFixings() of cons_linear.c
149- delete empty redundant knapsack and linear constraints after cleanup in SCIPmatrixCreate()
150- cleanup first constraints in SCIPcleanupConssVarbound(), SCIPcleanupConssSetppc(), and SCIPcleanupConssLogicor()
151- symmetry handling methods have not been added immediately after computing symmetries, which has been fixed
152- delay checking node limits after presolving to correctly continue up to the exceeding main node
153- simplified the objective sense assumption for the subproblems in the Lagromory separator
154- update effective root depth iteratively to avoid trapping it at a single child node
155- fixed that dualsparsify presolver did not always check do-not-multiaggregate variable flag
156- fixed bug in computing elements of orbits in orbital reduction
161- redefine isrelax to istight in cons_linear.c
168- A file cmake.log containing the changed options is written to the cmake build directory.
169- removed replacement of the settings of RelWithDebInfo
170- add compile option -ffp-contract=off or /fp:precise to enhance reproducibility across different systems
174- add flags -ffp-contract=off and /fp:precise to enhance reproducibility across different systems
181- added parameter "propagating/symmetry/symtiming" to determine when symmetries are computed and handled
183### Changed parameters
185- Disabled "propagating/symmetry/addconsstiming" since it is not used anymore.
186- Disabled "propagating/symmetry/ofsymcomptiming" since it is not used anymore.
188@section RN900 SCIP 9.0.0
189*************************
194- added simplification of abs(x)^n to x^n when n is even (simplify rule POW12)
195- in expression simplification, added possibility to expand power of sum with exponents larger than 2 (simplify rule POW7)
196- in expression simplification, added possibility to expand products with sums as factor when there are more than two factors (simplify rule SP12b)
197- in expression simplification, added possibility to allow expanding power of products with fractional exponent (simplify rule POW5a)
198- can now build with Lapack (used for solving nonlinear problems) explicitly; if IPOPT is used, then Lapack is accessed through it;
199 an interface to Lapack is available in lapack_calls.h
200- added support for logical constraints in binary variables and basic logical operators (and, or, not, equal) to AMPL .nl reader
201- indicator constraints now use the same slack variable for the linear constraints if binary variables are used multiple times
202 for indicator constraints
203- new diving heuristic indicatordiving that focuses on indicator variables which control semicontinuous variables
204- updated statistics on NLP relaxation; information on convexity of NLP has been added
205- added new bandit method (EXP.3-IX) that is the new default of the ALNS heuristic
206- added dialog to display recognized permutation symmetries ("display symmetry")
207- The symmetry detection code has been completely restructured. Instead of completely encoding symmetry information in
208 prop_symmetry.c, there is a new callback for constraint handlers, which returns symmetry relevant information by
209 encoding a constraint as a node and edge colored graph. This way, also custom constraint handlers can provide
210 symmetry information.
211- added special presolving step for logicor and set covering/packing for constraints with two variables and one independent variable
212- increased the depth field of the tree structure from 16 to 30 bits and the max depth of the search tree from 65534 to 1073741822
213- added new cut selector plugin called cutsel_ensemble. Performs a superset of hybrid cutsel. Implements new filtering methods and scoring options.
214- added new branching rule based on Gomory mixed-integer cuts
215- added new branching score to the reliability pseudo-cost branching rule
216- added new cut selector plugin called cutsel_dynamic. Performs a superset of hybrid cutsel. Implements new filtering methods and scoring options.
217- added monoidal strengthening to intersection cut generation of nlhdlr_quadratic
218- extended heuristic dps to run after processing the node and to use strict limits for the reoptimization step
219- extended obbt propagator to handle variables of the linear constraints corresponding to indicator constraints
220- added new heuristic heur_scheduler that models the selection of LNS and diving heuristics as a multi-armed bandit problem
221- added nonlinear handler for signomial expressions: adds cuts based on a difference of convex functions representation
222- Delayed separators are now called if no other cuts have been found. Previously, such separators were only called near stalling or when the separation rounds limit was reached.
223- added a new separator sepa_lagromory to generate Lagromory cuts in a relax-and-cut framework, i.e., GMI cuts generated
224 at different bases that are explored in the process of solving the Lagrangian dual problem at a node. This separator
226- when parsing nonlinear constraints from CIP files, the * after the number in a term is now optional if followed by a variable,
227 i.e., instead of 3*<x>*<y>, now also 3<x>*<y> can be read, but 3<x><y> is not supported;
228 this allows to read some CIP files that were written with SCIP < 8
229- when running bliss, we now limit the number of actually created generators and not the ones considered by bliss
231Performance improvements
232------------------------
234- Variable conflict-based addition of Schreier-Sims cuts for symmetry handling in prop_symmetry.c does no longer use
235 an expensive explicit conflict graph construction.
236- Only run propagation of indicator constraints if relevant variables have changed.
237- Propagation of indicator constraints propagates maximal activity of linear constraint to upper bound of slack variable.
238- Added initialization of LP relaxation for SOC constraints.
239- Avoided some numerical issues when separating SOC constraints.
240- If differentation of convex expression fails in convex nlhdlr, then a perturbed point is tried.
241- Use sassy/bliss as default symmetry computation package.
242- No longer linearize indicator constraints in undercover heuristic by default.
243- Deactivate pre-root heuristic zeroobj in undercover heuristic.
244- Added new branching score tiebreaker for reliability pseudo-cost branching rule
245- Try nearest bound if zero solution value is out of bounds in heuristic trivial.
250### New and changed callbacks
252- Added solution linearization callback for nonlinear handlers.
253 The nonlinear handler may use this callback to add tight cuts that use the given solution as reference point to the cutpool.
254 The callback is called if option constraints/nonlinear/linearizeheursol is enabled.
255- The callback for copying problem data SCIP_DECL_PROBCOPY() now has a parameter "original" indicating whether the original
256 or transformed problem should be copied. Similarly, SCIPprobCopy() in prob.h/c has such a parameter.
257- Added CONSGETPERMSYMGRAPH and CONSGETSIGNEDPERMSYMGRAPH callback for constraint handlers, which provides symmetry information about constraints to SCIP.
259### Deleted and changed API methods
261- SCIPtpiInitLock(), SCIPtpiDestroyLock(), SCIPtpiInitCondition(), SCIPtpiDestroyCondition() now take a double
262 pointer to SCIP_LOCK/SCIP_CONDITION, respectively.
263- Renamed SCIPtpiSumbitJob() to SCIPtpiSubmitJob().
264- SCIPcreateConsIndicatorLinCons(), SCIPcreateConsIndicatorGenericLinCons() do not allow binvar to be NULL anymore
265- Replaced SCIPnlrowSetCurvature() by SCIPsetNlRowCurvature().
266- SCIPsnprintf() now returns the required string length in case reallocation is necessary.
267- SCIPcomputeCoverUndercover() receives three more arguments which nonlinearities to cover
268- removed definition of SQRT
269- SCIPincludeObjConshdlr(), SCIPincludeConshdlr(), SCIPconshdlrCreate() receive two more arguments for the
270 conshdlr callbacks CONSGETPERMSYMGRAPH and CONSGETSIGNEDPERMSYMGRAPH
271- removed SYM_VARTYPE, SYM_OPTYPE, SYM_CONSTTYPE, SYM_RHSTYPE, SYM_MATRIXDATA
272- new parameter issigned for SCIPcomputeOrbitsSym()
273- new parameter symtype for SCIPcomputeComponentsSym()
274- new parameter symtype and permvardomaincenter for SCIPlexicographicReductionAddPermutation()
275- replaced parameters matrixdata and exprdata of SYMcomputeSymmetryGenerators() by graph
279- new functions for interfacing with Lapack: SCIPlapackIsAvailable(), SCIPlapackIsAvailable(), SCIPlapackComputeEigenvalues(), and SCIPlapackSolveLinearEquations
280 These functions should be used instead of SCIPisIpoptAvailableIpopt(), SCIPcallLapackDsyevIpopt(), and
281 SCIPsolveLinearEquationsIpopt() in the context of computing eigenvalues or solving linear equations.
282 If IPOPT is available, the calls will be passed on to Ipopt's interface to Lapack.
283- SCIPmultiplyBySumExprSum(), SCIPpowerExprSum()
285- SCIPgetPrimalDualIntegral() returns the primal dual integral stored in the statistics
286- new functions SCIPcreateConsIndicatorLinConsPure() and SCIPcreateConsIndicatorGenericLinConsPure() that
287 create indicator constraints from a linear constraint without a slack variable
288- SCIPgetNLPNlRowsStat() to retrieve counts on linear, convex, and nonconvex rows in NLP
289- SCIPnlhdlrSetSollinearize(), SCIPnlhdlrHasSollinearize()
290- SCIPbendersGetNLPParam()
291- new API functions SCIPlexicographicReductionGetStatistics(), SCIPlexicographicReductionPrintStatistics(),
292 SCIPlexicographicReductionPropagate(), SCIPlexicographicReductionAddPermutation(), SCIPlexicographicReductionReset(),
293 SCIPlexicographicReductionFree(), SCIPincludeLexicographicReduction(), for lexicographic reduction.
294- new API functions SCIPorbitopalReductionGetStatistics(), SCIPorbitopalReductionPrintStatistics(),
295 SCIPorbitopalReductionPropagate(), SCIPorbitopalReductionAddOrbitope(), SCIPorbitopalReductionReset(),
296 SCIPorbitopalReductionFree(), SCIPincludeOrbitopalReduction(), SCIPorbitopalReductionGetDefaultColumnOrdering(),
297 for orbitopal fixing.
298- new API functions SCIPorbitalReductionGetStatistics(), SCIPorbitalReductionPrintStatistics(),
299 SCIPorbitalReductionPropagate(), SCIPorbitalReductionAddComponent(), SCIPorbitalReductionReset(),
300 SCIPorbitalReductionFree(), SCIPincludeOrbitalReduction(), for orbital fixing.
301- new API functions SCIPgetShadowTreeEventHandlerExecutionTime(), SCIPshadowTreeGetShadowNodeFromNodeNumber(),
302 SCIPshadowTreeGetShadowNode(), SCIPgetShadowTree(), SCIPactivateShadowTree(), SCIPincludeEventHdlrShadowTree(),
303 for managing a copy of the branch-and-bound tree for symmetry handling purposes.
304- SCIPdotWriteOpening(), SCIPdotWriteNode(), SCIPdotWriteArc(), SCIPdotWriteClosing()
305- SCIPincludeCutselEnsemble(), SCIPselectCutsEnsemble() to include cutsel_ensemble or use the selection algorithm
306- SCIPincludeBranchruleGomory() includes new gomory cut based branching rule
307- SCIPgetVarAvgGMIScore(), SCIPincVarGMISumScore(), SCIPgetVarLastGMIScore(), SCIPsetVarLastGMIScore() set historical values used by SCIP's default branching rule
308- SCIPincludeNlhdlrSignomial() includes the signomial nonlinear handler
309- SCIPgetExprMonomialData() returns a monomial representation of a product expression
310- SCIPestimateRoot() computes estimators for roots with exponent in [0,1]
311- SCIPincludeCutselDynamic(), SCIPselectCutsDynamic() to include cutsel_dynamic or use the selection algorithm
312- SCIPincludeSepaLagromory() to include the new Lagromory separator
313- SCIPconsCompCheck() to compare two constraints based on their check priority
314- SCIPgetConsPermsymGraph() and SCIPgetConsSignedPermsymGraph() to access the (signed) permutation symmetry detection graph of a constraint
315- SCIPsetConshdlrGetPermsymGraph() and SCIPsetConshdlrGetSignedPermsymGraph() to set the (signed) permutation symmetry detection graph of a constraint
316- SCIPconshdlrSupportsPermsymDetection() and SCIPconshdlrSupportsSignedPermsymDetection() to access whether a conshdlr supports detection of (signed) permutation symmetries
317- new API functions for creating and manipulating a symmetry detection graph: SCIPcreateSymgraph(), SCIPfreeSymgraph(), SCIPcopySymgraph(), SCIPextendPermsymDetectionGraphLinear(),
318 SCIPaddSymgraphVarAggregation(), SCIPaddSymgraphOpnode(), SCIPaddSymgraphValnode(), SCIPaddSymgraphConsnode(), SCIPgetSymgraphVarnodeidx(), SCIPgetSymgraphNegatedVarnodeidx(),
319 SCIPupdateSymgraphLhs(), SCIPupdateSymgraphRhs(), SCIPfixSymgraphVarnode(), SCIPaddSymgraphEdge(), SCIPcomputeSymgraphColors(), SCIPgetSymgraphSymtype(), SCIPgetSymgraphVars(),
320 SCIPgetSymgraphNVars(), SCIPgetSymgraphNConsnodes(), SCIPgetSymgraphNNodes(), SCIPgetSymgraphNEdges(), SCIPgetSymgraphEdgeFirst(), SCIPgetSymgraphEdgeSecond(),
321 SCIPgetSymgraphVarnodeColor(), SCIPgetSymgraphNodeType(), SCIPgetSymgraphNodeColor(), SCIPisSymgraphEdgeColored(), SCIPgetSymgraphEdgeColor(), SCIPgetSymgraphNVarcolors(),
322 SCIPhasGraphUniqueEdgetype(), SCIPallocateSymgraphConsnodeperm(), SCIPcreateSymgraphConsnodeperm(), SCIPgetSymgraphConsnodeperm(), SCIPfreeSymgraphConsnodeperm(),
323 SCIPgetSymActiveVariables(), SCIPfreeSymDataExpr(), SCIPgetSymExprdataNConstants(), SCIPgetSymExprdataConstants(), SCIPgetCoefSymData(),
324 SCIPcreateSymOpNodeType(), SCIPgetSymOpNodeType()
325- SCIPexprhdlrSetGetSymdata(), SCIPexprhdlrHasGetSymData(), SCIPgetSymDataExpr(), SCIPcallExprGetSymData() to access symmetry data of expressions
326- SYMcheckGraphsAreIdentical() to check whether two symmetry detection graphs are identical
327- new functions SYMbuildSassyGraph(), SYMbuildSassyGraphCheck()
329- new definitions SCIP_DECL_CONSGETPERMSYMGRAPH, SCIP_DECL_EXPRGETSYMDATA
330- new member SYM_NODETYPE_CONS in SYM_NODETYPE enum
331- new members SYM_CONSOPTYPE_SUM, SYM_CONSOPTYPE_SLACK, SYM_CONSOPTYPE_COEF, SYM_CONSOPTYPE_RHS, SYM_CONSOPTYPE_LAST in SYM_CONSOPTYPE enum
332- new defintion SCIP_DECL_EXPRGETSYMDATA
333- new function SCIPdetectSingleOrDoubleLexMatrices()
335### Command line interface
337- Added optional parameter -i when calling SCIP in AMPL-mode (-AMPL parameter).
338 If -i is specified, a SCIP shell is started where normally SCIPsolve() would be called.
340### Interfaces to external software
342- added interface to nauty/traces for symmetry computation
343- added interface to sassy, a preprocessor for symmetry computation
344- The directory src/sassy contains the source code of sassy.
345- Added interface to Lapack (used for solving nonlinear problems).
346- The AMPL interface now supports parameters specified in AMPL command scripts via option scip_options.
347 The value of scip_options is expected to be a sequence of parameter names and values, separated by a space, e.g.,
348 `option scip_options 'limits/time 10 display/verblevel 1';`.
349 String values should not be quoted and spaces in string values are not supported.
350- sassy can be used now as preprocessor for nauty/traces
351- The solution status codes written to AMPL solution files now match those from https://mp.ampl.com/details.html#_CPPv4N2mp3sol6StatusE.
353### Changed parameters
355- change default value of parameter separating/filtercutpoolrel to FALSE
356- Shrunk range of parameter "propagating/symmetry/sstleaderrule" from [0,3] to [0,2], removed "MAXCONFLICTS"-option.
357- Removed reading/gmsreader/freeints. A default upper bound of +inf is now assumed for integer variables in GAMS (which is the case since GAMS 23.1).
358- Disabled "propagating/symmetry/symfixnonbinaryvars" since it is not used in the new symmetry code.
359- Replaced "propagating/symmetry/onlybinarysymmetry" with "propagating/symmetry/enforcecomputesymmetry" and set to FALSE by default.
360- Disabled "propagating/symmetry/performpresolving" since running orbital reduction during presolving is not effective.
361- Repurposed "propagating/symmetry/usedynamicprop" since it now also applies to lexicographic reduction.
362- Changed default value of parameter "propagating/symmetry/addsymresacks" from FALSE to TRUE.
366- separating/maxcutsgenfactor and separating/maxcutsrootgenfactor as factors (w.r.t. separating/maxcuts and
367 separating/maxcutsroot) for limits on the number of cuts generated (which used to be constants '2')
368- expr/pow/expandmaxexponent to specify limit on exponent when to expand power of sum
369- expr/pow/distribfracexponent to enable expanding power of products with fractional exponents
370- expr/product/expandalways to enable expanding any product with sums as factor (that is, also when more than two factors)
371- nlhdlr/convex/maxperturb to specify maximal perturbation of non-differential reference points
372- benders/default/nlpiterlimit to adjust iteration limit for NLP solver for Benders' decomposition NLP subproblems
373- limits/objectivestop to interrupt the solve as soon as a primal solution is found
374 that is at least as good as the given value
375- heuristics/undercover/{coverand,coverind,covernl} to control which nonlinearities to consider (by default only "and" and nonlinear constraints)
376- cutselection/ensemble/∗ all parameters for new ensemble cut selector
377- cutselection/dynamic/∗ all parameters for new dynamic cut selector
378- branching/relpscost/gmiavgeffweight specifies the weight in the relpscost branching score of the normalized efficacy of all generated GMI cuts (for a variable)
379 branching/relpscost/gmilasteffweight specifies the weight in the elpscost branching score of the normalized efficacy of the last generated GMI cut (for a variable)
380- nlhdlr/quadratic/usemonoidal to enable monoidal strengthening when separating quadratics with intersection cuts
381- nlhdlr/quadratic/trackmore to collect more statistics for monoidal strengthening when separating quadratics with intersection cuts
382- nlhdlr/quadratic/useminrep to use the minimal representation to compute cut coefficients when separating quadratics with intersection cuts
383- nlhdlr/quadratic/sparsifycuts to enable sparsification of intersection cuts for quadratics
384- heuristics/dps/reoptlimits to set strict limits for the reoptimization step in dps
385- heuristics/dps/timing to run dps after processing the node
386- heuristics/scheduler/∗ all parameters for new scheduler heuristic
387- nlhdlr/signomial/enabled, nlhdlr/signomial/maxnundervars, nlhdlr/signomial/mincutscale: parameters for the signomial nonlinear handler
388- separating/lagromory/freq to denote the frequency for calling Lagromory separator
389- separating/lagromory/away to denote the minimal integrality violation of a basis variable to try separation
390- separating/lagromory/dynamiccuts to denote whether the generated cuts be removed from LP if they are no longer tight
391- separating/lagromory/maxroundsroot to denote the maximal number of separation rounds in the root node
392- separating/lagromory/maxrounds to denote the maximal number of separation rounds in a non-root node
393- separating/lagromory/nmaxcutsperlproot to denote, in the root node, the maximal number of Lagromory cuts that can be
394 separated per explored basis of the Lagrangian dual
395- separating/lagromory/nmaxcutsperlp to denote, in a non-root node, the maximal number of Lagromory cuts that can be
396 separated per explored basis of the Lagrangian dual
397- separating/lagromory/perroundnmaxlpiters to denote the maximal number of separating LP iterations that are allowed per
399- separating/lagromory/dualdegeneracyratethreshold to denote the minimum dual degeneracy rate for the separator execution
400- separating/lagromory/varconsratiothreshold to denote the minimum variable-constraint ratio on the optimal face for the
402- many other advanced parameters for the Lagromory separator, which are also mentioned under separating/lagromory/∗
406- new data structure SYM_GRAPH to encode symmetry information from a constraint
407- new data structure SYM_EXPRDATA to encode symmetry information from expressions
408- replaced enum SYM_SYMTYPE by a complete new one; removed SYM_RHSSENSE, added SYM_NODETYPE and SYM_CONSOPTYPE
413- deleted the now unused files: tpi_none.h, tpi_openmp.h, tpi_tnycthrd.h, type_tpi_none.h, type_tpi_openmp.h, type_tpi_tnycthrd.h
418- new unittests for nlhdlr_quadratic that test monoidal strengthening and the use of the minimal representation to compute cut coefficients
419- unittests for nlhdlr_signomial
424- changed `set lim obj` to `set lim objective` in ctest since `obj` is no longer unambiguous
431- New flag -DLAPACK=on for linking with Lapack (must be available in the system)
432- added flag option "SYM=sbliss" for using sassy/bliss as a graph automorphism package
433- use SYM=sbliss by default, since sassy and bliss are now shipped with SCIP.
434- added flag option "SYM=snauty" for using sassy/nauty as a graph automorphism package
438- added flag option "nauty" for SYM variable to specify which graph automorphism package should be used
439- added flag option "sbliss" (sassy/bliss) for SYM variable to specify which graph automorphism package should be used
440- added flag option "snauty" (sassy/nauty) for SYM variable to specify which graph automorphism package should be used
441- use SYM=sbliss by default, since sassy and bliss are now shipped with SCIP
442- New flag LAPACK for linking with Lapack (must be available in the system)
443- A file scip/config.h is created in the build directory ($(OBJDIR)/include) now.
444 Defining NO_CONFIG_HEADER is no longer necessary and has no effect anymore.
449- Number of runs in which separation is enabled will now be correct as per "separating/maxruns" parameter. Earlier,
450 separation was enabled for "maxruns + 1" number of runs, i.e., separation was enabled even when "maxruns = 0" was set.
451- add safeguard for number of selected cuts
452- use double double precision for delta in activity updates of cons_linear.c
453- sort constraints in checkSolOrig() to keep the logic of constraint handlers intact
454- fixed make install when SHARED=no and make uninstall
455- check absolute coefficients relative to extremal average to avoid invalid unifications in normalizeCons()
456- enforce and check symmetry-based constraints to take their locks (in dual reductions) into account
457- flush changes at the end of SCIPlpiSetBase() in lpi_grb.c to apply the newly set basis correctly
462- The TPI has been changed to become mostly independent from the actual parallel interface during compile time.
463 For this, the locks and conditions are now pointers to abstract structs.
464- fixed that scip/def.h, the header for C preprocessor definition (`#define`'s), included headers for some SCIP type and function definitions
465 (scip/type_retcode.h, scip/type_message.h, scip/pub_message.h)
468@page RN8 Release notes for SCIP 8
470@section RN810 SCIP 8.1.0
471*************************
476- fixed that scaling of rows in Gurobi interface (SCIPlpiScaleRow()) changed infinite sides to large finite ones (1e20) when scale factor is negative
477- check whether objective limit is truly reached in SCIPlpiIsStable()
478- if an objective limit is set and Mosek claims that it is exceeded, check that this is indeed the case in SCIPlpiIsStable()
479- the .mps file reader was extended to additionally accept .mps files with the objective sense section on one line
480- ensure that delayed cutpool separation does not happen if enough cuts have been found already
481- fixed that a Gurobi or Mosek interface (LPI) could not be freed from a thread different than the one it was created in, which lead to problems when, e.g., using the concurrent optimizer
482- in cons_varbound if both variables are fixed, instead of propagating the constraint check the feasibility of the constraint since propagating can lead to unnecessary numerical troubles
483- fixed memory leak in branching rule "distribution"
484- fixed that undercover did not enforce that sufficiently many variables in an and-constraints were fixed to have it linearized in the generated sub-scip
485- fixed two bugs in cons_varbound: avoid adding variable bounds if vbdcoef is infinite and unlock/lock variables if lhs/rhs/vbdcoef are changed
486- globalize constraint changes before bound changes during the effective root shift in treeSwitchPath() to correctly update variable locks by avoiding global bounds with outstanding bound change events when deleting constraints
487- fixed error when attempting to copy SCIP with activated pricers
488- remove integrality check for implicit integral variables in cons_integral.c, updated the definition for variable type implicit integer to be more explicit that these variables can take fractional values, and updated FAQ entry
489- updated and, or, and pseudoboolean constraint handlers to better handle fractional implicit integer variables in enforcement
490- avoid invalid strong Chvatal-Gomory cuts by ceiling with tolerance in the calculation of parameter k and flooring slack coefficients with standard epsilon tolerance as well as quad precision
491- add missing row links to columns in SCIPflushRowExtensions() required to maintain correct row norms
492- restrict separator intobj to solutions for which there can be no better feasible integral objective values to avoid cutting them off
493- delay removal of clique lists from SCIPvarRemoveCliquesImplicsVbs() into cliqueCleanup() to avoid segmentation faults by incomplete cleanups after variable conversions
494- reject sub-solutions with invalid objectives in SCIPtranslateSubSols() due to contradicting infinite contributions
495- correct column index in getMinMaxActivityResiduals() to make presolver dualinfer work
496- copy quiet flag from main scip's message handler to the one of solverscip in concurrent optimization
497- avoid bound tightening cycles towards huge redundancy bounds in fullDualPresolve() to avert fatal numerical trouble in representing vertices of linear relaxations with unbounded domains
498- fix problem where debug solution did not work if branching constraints are present
499- update index of dominating variable on coefficient deletion in dualPresolving() of constraint handler logicor
500- pass on flags from a redundant to the implying varbound constraint in preprocessConstraintPairs() to avoid suboptimal fixings by model relaxations
501- apply reductions of dualinfer only if a dual solution exists (primal is bounded)
502- before presolving is finished check solutions before retransforming them including tiny values to keep check flags consistent
503- disable heuristics before and during presolving in benders decomposition to avoid messing up the objective structure in the solution store by dropping auxiliary variables in the required retransformations
504- correct local flag of singleton conflict constraints in tightenSingleVar() against invalid bound globalization
505- respect unboundedness in the computation of activity bounds in conflict.c to avoid invalid huge bounds due to small coefficients on unbounded variables
506- ensure positive sides of a linear constraint when recognizing a set partition in rangedRowSimplify() to account for redundancy issues
507- relax numerical conditions for variable aggregations to avert invalid variable fixings
508- fixed harmless read of uninitialized data when creating parameters
509- fix call of SCIPnlpiOraclePrintProblem in nlpi_worhp
511Performance improvements
512------------------------
514- Use sassy/bliss as default symmetry computation package.
519### Interfaces to external software
521- added interface to nauty/traces for symmetry computation
522- added interface to sassy, a preprocessor for symmetry computation
523- The directory src/sassy contains the source code of sassy.
530- added flag option "SYM=sbliss" for using sassy/bliss as a graph automorphism package
534- added flag option "nauty" for SYM variable to specify which graph automorphism package should be used
535- added flag option "sbliss" for SYM variable to specify which graph automorphism package should be used
536- use SYM=sbliss by default, since sassy and bliss are now shipped with SCIP
541- the parameter change callback is no longer called at the moment a parameter is created
543@section RN804 SCIP 8.0.4
544*************************
549- use quad precision in cutsSubstituteMIR() for substituting slack variables into CMIR cuts
550- use quad precision for activity computations in cons_linear.c
552### Deleted and changed API methods
554- SCIPshrinkDisjunctiveVarSet() no longer attempts to cutoff the current node if it finds the
555 given disjunction to be infeasible; it is now in the responsibility of the caller to act accordingly
560- added XML parser routines from src/xml/xml.h
562### Interfaces to external software
564- updated XPRESS interface to work with XPRESS 41 as well
565- new interface to LP solver HiGHS (lpi_highs.cpp)
567### Changed parameters
569- changed integer parameter "propagating/symmetry/recomputrestart" from range {0, 1, 2} to being fixed at value 0
574- added new checks for objective, bounds and sides inside the scaling tests in lpi/change.c
579- relax condition of assert in lpSolve to hold only if lp/checkstability is true
580- OPB reader: dynamically increase the size of the line buffer for reading in getMaxAndConsDim()
581- Enabled the solution limit checks in SCIPsolveIsStopped in solve.c when in SCIP_STAGE_PRESOLVING
582- fix quad precision comparison for the calculation of knapsackcover constraints.
583- force copying of symmetry constraints for concurrent solve
584- increase the precision of double multiplications in quad precision environments
585- corrected handling of different variable types in symmetry
586- orbitope detection: refine computation of overlap structure and fixed bug in finding orbitope generators
587- ensure that winner is always determined in concurrent mode
588- when a row with invalid index range is added to the global cutpool, update the indices instead of failing with an assert
589- update of watched literals in cons_xor.c and ensure that fixed variables are counted in propacateCons()
590- avoid some numerical issue in check for redundant variables in linear constraints (introduced with version 8.0.2)
591- more rows are treated as being integral in cutsSubstituteMIR() for CMIR cuts
592- fixed several relaxations of the rhs of cuts to 0 in cuts.c
593- avoid aggregation into a single linear constraint if they should not be upgraded (needed for indicator constraints)
594- apply effective root changes before fork is repropagated during treeSwitchPath() in tree.c
595- avoid invalid objective value for solutions generated from an unbounded LP relaxation in case of a nonlinear objective function
596- disable recomputing symmetries after a restart (constraint removal is not permitted)
597- avoid cutting off optimal solutions for small feasibility tolerances in conflict analysis
598- initialize variable in presol_dualsparsify.c
599- fix in presolving of variable bound constraints to use absolute instead of relative difference
600- free variable histories in reoptimization mode
601- handle whitespaces in interactive shell history consistently
602- check and enforce equalities on which the objective is projected in cons_linear.c
603- ensure row feasibilities of solution shiftings in heur_oneopt.c and heur_twoopt.c
604- remove rounded row check blocking tolerable primal solutions in cons_varbound.c
605- fixed that presolve of logicor-constraints may have attempted to cutoff a root of the not yet existing branch-and-bound tree
606- only consider positive slack variables as active in benders.c
607- in the feasibility check of and/or constraints, allow for fractional values in operands
608- fixed linear outer-approximation for some composite absolute-value expressions
613- Extended documentation of the parameter limits/solutions to point out that the limit is first checked in presolving
614- Added more information about using SCIPcache- and SCIPflushRowExtensions() to documentation and comments
615- Extended the `how to add' sections of the documentation by adding information on how to include default plugins into SCIP
617@section RN803 SCIP 8.0.3
618*************************
620Examples and applications
621-------------------------
623- Externalize STP and PolySCIP applications
628### Command line interface
630- When running the AMPL interface, the .nl filename extension does not need to be omitted for the input file anymore.
637- Forbid CMAKE_BUILD_TYPE nonstandard values
638- Move -I/path/to/src/amplmp/include to front of compiler flags for include directories
645- fixed an incorrect handling of xor constraints
646- the feasibility checker for integrality constraints now uses checkintegrality even for implied integers
647- skip integrality check in cons_integral for relaxation-only implicit-integer variables
648- fixed an issue caused by aggregated variables not added to a hashmap in the xor constraint handler
649- changed function solveRowEchelonGF2 in cons_xor.c to avoid errors if rank is 0
650- fixed that the implication presolver tried to aggregate or tighten bounds of multiaggregated variables
651- fixed a sign check in detection of linear constraints that are parallel to the objective
652- fixed bug in Clp and lpi_clp with missing basis information when calling the barrier with crossover; needs new Clp version
653- do not assume aggregation is successful in cons_setppc.c
658- Changed license to Apache 2.0, see https://www.apache.org/licenses/LICENSE-2.0.
659- When an LP could not be solved accurately, scaling is now turned off as a last fall-back method.
660- Methods for using the debug solution mechanism SCIPdebugAddSolVal, SCIPdebugGetSol, SCIPdebugGetSolVal,
661 SCIPdebugSolIsValidInSubtree, SCIPdebugIsMainscip, SCIPdebugSolEnable, SCIPdebugSolDisable, SCIPdebugSolIsEnabled,
662 SCIPwithDebugSol are now exported
664@section RN802 SCIP 8.0.2
665*************************
670### Deleted and changed API methods
672- added input parameter SCIP_Bool initiallp to SCIPcutselsSelect
673- changed function type int to SCIP_Longint for SCIPcutpoolGetMaxNCuts
674- replaced SCIPsepastoreGetNCutsFound with SCIPsepastoreGetNCutsAdded following the naming convention for the new statistics
675- replaced SCIPsepaIncNAppliedCuts with SCIPsepaIncNCutsApplied
679- added SCIPsepastoreGetNCutsAdded, SCIPsepastoreGetNCutsAddedViaPool, SCIPsepastoreGetNCutsAddedDirect
680- added SCIPsepaIncNCutsAdded, SCIPsepaDecNCutsAdded, SCIPsepaIncNCutsApplied, SCIPsepaGetNRootCalls, SCIPsepaGetNCutsAdded, SCIPsepaGetNCutsAddedViaPool, SCIPsepaGetNCutsAddedDirect, SCIPsepaGetNCutsAppliedViaPool, SCIPsepaGetNCutsAppliedDirect
681- added SCIPcutpoolGetNRootCalls, SCIPcutpoolGetNCutsAdded, SCIPcutpoolAddMaxNCuts, SCIPcutpoolSetTime, SCIPcutpoolAddNCalls, SCIPcutpoolAddNRootCalls, SCIPcutpoolAddNCutsFound, SCIPcutpoolAddNCutsAdded,
682- added SCIPcutselGetNCalls, SCIPcutselGetNRootCalls, SCIPcutselGetNRootCuts, SCIPcutselGetNRootForcedCuts, SCIPcutselGetNRootCutsFiltered, SCIPcutselGetNLocalCuts, SCIPcutselGetNLocalForcedCuts, SCIPcutselGetNLocalCutsFiltered,
684### Interfaces to external software
686- Added compatibility with Mosek 10.0.18.
690- new parameters to turn on more statistics: misc/showdivingstats (diving heuristics), heuristics/alns/shownbstats (ALNS), estimation/showstats (tree size estimation)
694- added nrootcalls and ncutsadded to SCIP_Cutpool
695- added fromcutpool flag to SCIP_Row and fixed 33 bit allocation
696- added ncalls, nrootcalls, nrootcutsselected, nrootcutsforced, nrootcutsfiltered, nlocalcutsselected, nlocalcutsforced, nlocalcutsfiltered to SCIP_Cutsel
697- added ncutsadded, ncutsaddedviapool, ncutsaddeddirect, ncutsappliedviapool, ncutsapplieddirect, nrootcalls to SCIP_Sepa
698- added ncutsadded, ncutsaddedviapool, ncutsaddeddirect to SCIP_Sepastore
699- fixed statistics of relaxators w.r.t. number of times conss/cuts were added
706- new option `-DAUTOBUILD` that configures scip with dependencies on availability.
707 Packages like Ipopt, PaPILO, Readline, Zimpl, ZLIB, GMP, Worhp are automatically found and linked, otherwise ignored.
708 The individual flags for these packages are ignored. This makes a quick build easier. It is by default set to off.
713- read objective offset from ZIMPL files
714- Make sure that objective limit is disabled if not all variables are in the LP. If we would run into
715 an objective limit in this case, the results of the LP solver are unclear.
716- fixed bug in reopt.c, which occured for bounds outside of current valid bounds
717- fixed problem with recomputing symmetries after a restart
718- fixed bug in SCIPcalcMIR() with wrong order of arguments for removeZerosQuad()
719- fixed segmentation fault in update of cut statistic
720- fixed bug in presolving of and constraints by merging variables with multiple occurrences before cliquePresolve()
721- fixed bug in dual presolving of linear constraints by setting implicit integers to integers in multi-aggregation
722- fixed update of presolve statistics on added constraints and changed coefficients in constraint handler for nonlinear constraints
723- fixed bug with reading CIP files with large constraints split over several lines
724- fixed bug with infinite bounds in the computation of conflict cuts
725- fixed check for unbounded solution constructed by SCIPlpGetUnboundedSol(): The constructed solution is very likely infeasible
726 since scaling increases small numerical feasibility violations. Therefore, the solution is now always accepted. However, the
727 feasibility of the ray is now checked. This fix now might lead to several rounds of separation in order to resolve unbounded solutions,
728 whereas previously SCIP started to branch immediately.
729- changed to absolute tolerances in all redundancy checks for linear constraints
734- Added extended cutselector statistics splitting between root node specific and general statistics
735- Added extended and refined cutpool statistics showing the number of cuts added from the cutpool to the sepastore
736- Added extended and refined separator statistics to get a better view of the individual generators performance
737- turned off output of statistics for the following information by default:
738 diving heuristics, ALNS neighborhood information and tree size estimation statistics;
739 they can be turned on using the following new parameters:
740 misc/showdivingstats (diving heuristics), heuristics/alns/shownbstats (ALNS), estimation/showstats (tree size estimation)
742@section RN801 SCIP 8.0.1
743*************************
748- clique lifting in cons_setppc (parameter enablecliquelifting) is only disabled if it has been applied
749- avoid warning if Mosek has reached/exceeded the objective limit
750- improved curvature check for quadratic expressions when extended formulations are disabled
752Examples and applications
753-------------------------
755- Fixed handling of enforcing in the TSP example.
760### Interfaces to external software
762- Added compatibility with Mosek 10.0.13.
767- BLISS is now built from the vendored version from https://github.com/ds4dm/Bliss
771- avoid warnings about unrecognized compiler warning silencing options when compilation with GCC fails
772- adjust mosek find module to version 9.3
773- added cmake compatibility for ipopt versions 3.14.x
777- avoid warnings about unrecognized compiler warning silencing options when compilation with GCC fails
778- fixed that compilation with MS/Intel compilers on Windows and Cray compilers was broken when enabling PAPILO
783- fixed uninitialized array in detection of suborbitopes
784- Fixed problem with reading long lines in LP/FZN/OPB/Diff-files. The buffer is now reallocated,
785 which also should be much faster.
786- fixed that recursive products in expressions were sometimes not flattened
787- fixed that expressions in original variables could not be simplified
788- fixed handling of objective limit with Mosek
789- made SCIPlpiGetSolverName()/SCIPlpiGetSolverDesc() thread-safe for LP Solvers (Cplex,Gurobi,Glop,Mosek,SoPlex,Xpress)
790- made SYMsymmetryGetName() thread-safe for Bliss
791- fixed memory allocation issue in detection of SOC nlhdlr
792- fixed that reaching the walltime limit in Ipopt was not handled properly
793- Deactivated dual fixing of unlocked variables with zero objective in presol_milp that SCIP is unable to postsolve.
794- set the column flag kImplInt for implicit integers in the papilo problem
795- fixed bug in propagation of indicator constraints (one case always reported a change through propagation)
797@section RN800 SCIP 8.0.0
798*************************
803- Variables that were marked as relaxation-only and that were not used in any solution (SCIP_SOL)
804 are now deleted when during a restart.
805- New symmetry handling method, symmetry handling inequalities based on the Schreier Sims table,
806 which is able to handle symmetries of arbitrary kinds of variables.
807- Revise way in which external memory (e.g., of LP-solver) is estimated.
808- The symmetry code can now heuristically search for orbitopes that do not completely handle
809 a symmetry component and add certain Schreier Sims cuts to such components.
810- The LPIs for Gurobi and Mosek are thread-safe now.
811- The complete code is now thread-safe by default.
812- New separator to generate mixing cuts (works well for stochastic programming with probabilistic constraint).
813- New parsing routines for cons_orbisack and cons_symresack.
814- Variables can now be marked to forbid aggregation.
815- Heuristic PADM can now reoptimize found solution with original objective function.
816- Added code to support debugging of catching or releasing of variables to var.c (prints backtrace
817 when catching and releasing).
818- SCIPintervalSin() and SCIPintervalCos() are now rounding-safe.
819- Removed special handling of second-order cones in undercover heuristic for now.
820- Removed use of Hessian sparsity pattern for nonquadratic nonlinear constraints in undercover heuristic.
821- Added reader for AMPL .nl files.
822- New separator sepa_rlt to compute cuts via the reformulation-linearization technique (RLT).
823- New separator sepa_minor to compute cuts from 2x2 minors of a violated semidefiniteness constraint that is
824 implied by the extended formulation for bilinear products.
825- New separator sepa_interminor to compute intersection cuts from 2x2 (not only principle) minors of a violated
826 rank-one constraint that is implied by the extended formulation for bilinear products.
827- Symmetry handling has been extended to detect also symmetries between variables that also appear in nonlinear constraints.
828- Improved OBBT propagator by only considering variables that are contained in at least one nonconvex expression that has an auxiliary variable.
829- Default parameter settings for NLP solves are now defined independently of the NLP solver.
830- Added table to print statistics on NLP solvers.
831- Knapsack, linear, logicor, setppc, and varbound constraints now add themselves to the NLP relaxation, if enabled.
832 And, linking constraints and bounddisjunctions in one variable are added to the NLP relaxation now.
833- Ipopt interface now supports warmstarts from a full primal/dual solution pair.
834- Extended data structure SCIP_ROWPREP and routines to assemble a linear inequality before it is turned into a SCIP row and
835 made it available via the API.
836- MIR procedure is now available for strengthening the Benders' optimality cut
837- SCIPbranchcandCalcLPCands() now also returns fractional variables in unbounded solutions.
838- New emphasis "benchmark" to avoid different solving paths that may come from checking remaining memory.
839- New plugin type for cut selection: users can now include their own cut selection rules, default rule moved to cutsel_hybrid.
840- New construction heuristic DPS which additionally needs a user-provided decomposition and splits the problem into several sub-SCIPs
841 according to this decomposition. The sub-SCIPs are solved and updated repeatedly until a feasible solution of the original problem is found.
844- Removed support for expression types min and max for now. Removed support for expression type sign.
845 Removed complex expression types sum, product, linear, quadratic, polynomial.
846 Removed support for parameterized expressions.
847- Added support for expression types sin, cos, and entropy. Added an expression type that stores a SCIP variable.
848- Added handling of sin and cos expressions in OSiL reader.
849- Added handling of sin, cos, and tan expressions in ZIMPL reader.
850- Added expression handler plugin type, removed user expression type.
851- Replaced expressions, expression trees, and expression graphs by a new implementation of expressions.
852- Added differentiation methods (Gradients and Hessian directions) to expressions.
853- Added integrality information to expressions.
854- Added comparison and hashing of expressions.
855- Improved simplification of expressions and identification of common subexpressions, in particular terms that appear
856 equally in several quadratic functions are now identified.
857- Expression simplification now expands powers also when the resulting exponents will be larger than 2.
858- Added table to print statistics on expression handlers.
859- Removed interval-arithmetic evaluation from expression interpreter (interfaces to automatic differentiation codes).
860- Hessians for user-provided expression handlers are not available in the NLP solver interfaces for now.
861- Sparse Hessians are now returned by expression interpreter. Removed dense Hessians.
863Constraint handlers for NLP:
864- cons_nonlinear has been completely rewritten and now handles constraints of the form lhs <= expr <= rhs, where
865 expr is an expression using the new expression type. A linear part of a nonlinear constraint is no longer distinguished.
866- Methods that work on a particular nonlinear structure are now implemented via nonlinear handlers (nlhdlr).
867 These handlers are plugins of cons_nonlinear and interact with cons_nonlinear by detecting structures in expressions and
868 providing propagation and separation mechanisms.
869- Added nlhdlr "default" as a mandatory nlhdlr: this is a nlhdlr that gets active on expressions that no other nlhdlr handles.
870 It then uses the callbacks implemented in expression handlers to provide domain propagation and linear under/overestimates.
871- Added nlhdlr for quadratic expressions: domain propagation that was previously part of cons_quadratic; separation via intersection cuts (currently disabled).
872- Added nlhdlr for bilinear expressions: collects bilinear products and provides under/overestimation of a product over a 2D-projection of the LP.
873- Added nlhdlr for convex and concave expressions: detection of convex/concave subexpressions and linear under/overestimation.
874- Added nlhdlr for quotients: detects quotients, provides specialized linear under/overestimation and domain propagation for univariate quotients.
875- Added nlhdlr for perspective reformulations: detects expressions in semi-continuous variables and tightens linear
876 under/overestimates of these expressions by applying a perspective transformation.
877- Added nlhdlr for second-order cones: detects second-order cone constraints (as ||x|| <= t or a quadratic that can written like that) and
878 separates on a disaggregated reformulation (similar to cons_soc previously).
879- Removed constraint handlers abspower, bivariate, quadratic, and soc.
880- Removed simplification of duplicate abspower constraints for now.
881 Removed simplification of abspower constraints with loose variables.
882 Removed resolving of domain propagation (ConsResProp callback) and conflict analysis for abspower constraints.
883 Removed propagation of varbounds for variables of abspower constraints.
884 Removed reformulation of abs(x)^p * x into signpower expression for now.
885- Removed reformulation of SOC constraints when adding to the NLP.
886 Removed possibility to add linearizations a la Glineur or BenTal&Nemirovski for SOC constraints.
887- Removed possibility to disaggregate quadratic constraints.
888 Removed lifted tangent inequalities for bilinear terms in quadratic constraints.
889 Removed option to project LP solution onto feasible region of a quadratic constraint via interior point or gauge function.
890 Removed handling of unbounded LPs when enforcing quadratic constraints.
891- Removed construction of cuts from interval gradients for nonlinear constraints.
892 Removed possibility to pretend that all nonlinear constraints are convex.
893 Removed possibility to create local or non-initial nonlinear constraints for now.
894- Removed explicit reformulation of nonlinear constraints in presolve.
895 An extended formulation is now generated implicitly and used to construct the LP relaxation,
896 but the original formulation is used to check feasibility, propagate variable domains, etc.
897 Variables that are added for the extended formulation are now marked as relaxation-only.
898- Improved locking of nonlinear variables in nonlinear constraints by taking monotonicity into account.
899- Improved mechanisms to detect and handle structures in nonlinear constraints, which allows for several algorithms
900 to work simultaneously on equal or overlapping expressions.
901- Improved linearization of (sums of) products of binary variables, e.g., clique information is now taken into account.
902 Removed option to linearize products between a binary and a non-binary variable.
903- Nonlinear constraints with the same function (but possibly different left- or right-hand-side) are now merged.
904- When a variable appears in only one concave less-or-equal constraint, it will be fixed to one of its bounds in more cases now.
905- New branching rule for variables in nonlinear constraints (implemented in cons_nonlinear) that scores candidates
906 based on constraint violation, variable type, and pseudo-costs simultaneously.
907- Added tables to print statistics of nonlinear constraint handler and nonlinear handlers.
909Performance improvements
910------------------------
912- Use the objective cutoff row as base row for separation in sepa_aggregation.c.
913- Separate lifted cover cuts based on newer lifting function of Letchford and Souli (2019) in sepa_aggregation.c.
914- In-tree restarts due to tree size estimation have been made compatible with orbital fixing.
915- Improved upgrade of orbisacks to packing/partitioning orbitopes.
916- Improved running time of symresack cover separation.
917- Improved propagation algorithm for orbisack and symresack.
918- Improved handling for expressions of type signpower in CppAD interface by making use of CppADs conditional expressions.
919- Faster reevaluation of Hessian for quadratic expressions in CppAD interface.
920- Enabled optimization of taped expressions in the CppAD interface.
921- Sparse Hessian evaluation for expressions with sparse Hessian in the CppAD interface.
922- Disabled branching on variables that are added for the extended formulation of a nonlinear constraint.
923- Prefer branching on variables in nonconvex terms of nonlinear constraints also if a cut could be generated but would yield a small reduction in the convexification gap only.
924- When violations of nonlinear constraints are tiny, the feasibility tolerance for the LP relaxation may now be reduced temporarily to allow for cuts to have an effect.
925- Improved under/overestimation of multidimensional vertex-polyhedral (e.g., multilinear or concave) functions by use of scaling and keeping the cut-generating LP around.
926- Products in nonlinear constraints are no longer disaggregated for the extended formulation.
927- No longer relax bounds of integral variables when computing bounds on activity in nonlinear constraints.
928- Revised and improved Ipopt interface.
929- Revised and improved subNLP primal heuristic, in particular choice of iteration limit and starting condition and reuse of subSCIP.
930- Merge strongcg into the gomory separator to avoid computing the same base equality twice. The files
931 sepa_strongcg.{h|c} have been removed.
932- The RENS neighborhood in ALNS now fixes fractional variables if necessary for reaching its target fixing rate.
933- Use cpsolver emphasis in sepa_rapidlearning.
934- If decomposition/maxgraphedge = 0, the computation of the block graph is completely turned off.
935- Fixed a performance bug in cons_integral.c where rounding information was passed incorrectly to the generic diving algorithm.
937Examples and applications
938-------------------------
940- Add c++ Sudoku example
941- Removed circle.c and renamed string.c to spring.c in CallableLibrary example.
942- SCIP-Jack (Steiner tree application):
943 Most files have been modified and many new ones have been added (code base more than doubled).
944 Two new problem classes are supported: maximum-weight connected subgraph problem with budget constraints, partial-terminal node-weighted Steiner tree problem.
945 Major performance improvements accross all problem classes that are supported.
950### New and changed callbacks
952- extend SEPAEXEC{LP,SOL} callbacks by parameter "depth", which should be used within separation instead of SCIPgetCurrentDepth()
953- extend SCIPseparateSolCutpool() by parameter "pretendroot", which is passed to SCIPcutpoolSeparate() instead of SCIPtreeGetCurrentDepth(scip->tree) == 0
954- removed SCIP_DECL_EXPRGRAPHVARADDED, SCIP_DECL_EXPRGRAPHVARREMOVE, SCIP_DECL_EXPRGRAPHVARCHGIDX
955- removed SCIP_DECL_USEREXPRESTIMATE, SCIP_DECL_USEREXPREVAL, SCIP_DECL_USEREXPRINTEVAL, SCIP_DECL_USEREXPRCURV, SCIP_DECL_USEREXPRPROP, SCIP_DECL_USEREXPRCOPYDATA, SCIP_DECL_USEREXPRFREEDATA, SCIP_DECL_USEREXPRPRINT
956- added SCIP_DECL_EXPR_OWNERFREE, SCIP_DECL_EXPR_OWNERPRINT, SCIP_DECL_EXPR_OWNEREVALACTIVITY, SCIP_DECL_EXPR_OWNERCREATE
957- added SCIP_DECL_EXPR_INTEVALVAR, SCIP_DECL_EXPR_MAPEXPR
958- added SCIP_DECL_EXPRCOPYHDLR, SCIP_DECL_EXPRFREEHDLR, SCIP_DECL_EXPRCOPYDATA, SCIP_DECL_EXPRFREEDATA, SCIP_DECL_EXPRPRINT, SCIP_DECL_EXPRPARSE, SCIP_DECL_EXPRCURVATURE, SCIP_DECL_EXPRMONOTONICITY, SCIP_DECL_EXPRINTEGRALITY, SCIP_DECL_EXPRHASH, SCIP_DECL_EXPRCOMPARE, SCIP_DECL_EXPREVAL, SCIP_DECL_EXPRBWDIFF, SCIP_DECL_EXPRFWDIFF, SCIP_DECL_EXPRBWFWDIFF, SCIP_DECL_EXPRINTEVAL, SCIP_DECL_EXPRESTIMATE, SCIP_DECL_EXPRINITESTIMATES, SCIP_DECL_EXPRSIMPLIFY, SCIP_DECL_EXPRREVERSEPROP
959- removed SCIP_DECL_QUADCONSUPGD
960- added SCIP_DECL_VERTEXPOLYFUN
961- added argument nvarexprs to SCIP_DECL_NONLINCONSUPGD to inform upgrade method about number of variables in constraint
962- removed SCIP_DECL_EXPRGRAPHNODEREFORM
963- added SCIP_DECL_NLHDLRCOPYHDLR, SCIP_DECL_NLHDLRFREEHDLRDATA, SCIP_DECL_NLHDLRFREEEXPRDATA, SCIP_DECL_NLHDLRINIT, SCIP_DECL_NLHDLREXIT, SCIP_DECL_NLHDLRDETECT, SCIP_DECL_NLHDLREVALAUX, SCIP_DECL_NLHDLRINTEVAL, SCIP_DECL_NLHDLRREVERSEPROP, SCIP_DECL_NLHDLRINITSEPA, SCIP_DECL_NLHDLREXITSEPA, SCIP_DECL_NLHDLRENFO, SCIP_DECL_NLHDLRESTIMATE
964- replaced BMS_BLKMEM* blkmem argument of SCIP_DECL_NLPICOPY by SCIP* scip, removed targetnlpi argument
965- added SCIP* scip and SCIP_NLPIDATA** nlpidata arguments to SCIP_DECL_NLPIFREE
966- added SCIP* scip to SCIP_DECL_NLPIGETSOLVERPOINTER, SCIP_DECL_NLPICREATEPROBLEM, SCIP_DECL_NLPIFREEPROBLEM, SCIP_DECL_NLPIGETPROBLEMPOINTER, SCIP_DECL_NLPIADDVARS, SCIP_DECL_NLPIADDCONSTRAINTS, SCIP_DECL_NLPISETOBJECTIVE, SCIP_DECL_NLPICHGVARBOUNDS, SCIP_DECL_NLPICHGCONSSIDES, SCIP_DECL_NLPIDELVARSET, SCIP_DECL_NLPIDELCONSSET, SCIP_DECL_NLPICHGLINEARCOEFS, SCIP_DECL_NLPICHGOBJCONSTANT, SCIP_DECL_NLPISETINITIALGUESS, SCIP_DECL_NLPISOLVE, SCIP_DECL_NLPIGETSOLSTAT, SCIP_DECL_NLPIGETTERMSTAT, SCIP_DECL_NLPIGETSOLUTION, SCIP_DECL_NLPIGETSTATISTICS
967- replaced SCIP_DECL_NLPICHGEXPRTREE by SCIP_DECL_NLPICHGEXPR
968- removed nquadelems, quadelems, exprvaridxs arguments from SCIP_DECL_NLPIADDCONSTRAINTS, changed exprtrees argument to exprs
969- removed nquadelems, quadelems, exprvaridxs arguments from SCIP_DECL_NLPISETOBJECTIVE, changed exprtree argument to expr
970- removed SCIP_DECL_NLPICHGQUADCOEFS, SCIP_DECL_NLPICHGNONLINCOEF, SCIP_DECL_NLPISETMESSAGEHDLR
971- added SCIP_NLPIPROBLEM* problem to SCIP_DECL_NLPIGETSOLVERPOINTER
973### Deleted and changed API methods
975- When calling SCIPdelVar() in the SCIP_STAGE_PROBLEM stage, it is now documented as the user's responsibility to ensure
976 the variable is not present in any constraints. Otherwise, SCIPsolve() now returns SCIP_INVALIDDATA.
977- removed SCIPselectCuts(), replaced by SCIPselectCutsHybrid() of the hybrid cut selector plugin
978- If SCIPvarMarkRelaxationOnly() is called for a variable, then this now need to happen before the
979 variable is added to the transformed problem (SCIPaddVar()).
980 SCIPvarMarkRelaxationOnly() will automatically call SCIPvarMarkDeletable().
981- SCIPcomputeOrbitsFilterSym() and SCIPcomputeComponentsSym(): Type of argument componentblocked
982 changed from SCIP_Shortbool* to unsigned*.
983- removed SCIPsetParam()
984- SCIPcreateConsOrbitope() and SCIPcreateConsBasicOrbitope() have two new arguments "usedynamicprop"
985 and "mayinteract" to encode whether a dynamic reordering of the orbitope rows shall be used in
986 full orbitope propagation and whether the orbitope might interact with other symmetry handling
987 methods, respectively.
988- internal function SCIPgetPropertiesPerm() has been replaced by SCIPisInvolutionPerm()
989- internal function SCIPgenerateOrbitopeVarsMatrix() has new arguments "storelexorder", "lexorder",
990 "nvarsorder", "maxnvarsorder" to compute and store the lexicographic order defined by an orbitope
991- renamed SCIPcomputeArraysIntersection() and SCIPcomputeArraysSetminus() to
992 SCIPcomputeArraysIntersectionInt() and SCIPcomputeArraysSetminusInt(), respectively, and changed
993 their return type from SCIP_RETCODE (which _always_ was SCIP_OKAY) to void
994- removed SCIPincludeDialogDefault(), use SCIPincludeDialogDefaultBasic() instead and check whether you also need SCIPincludeDialogDefaultSet() and SCIPincludeDialogDefaultFix()
995- removed exprint argument from SCIPaddNlRowGradientBenderscutOpt()
996- added copyexprhdlrs argument to SCIPcopyPlugins() (19th position)
997- added copycutselectors argument to SCIPcopyPlugins() (10th position)
998- removed refpoint argument from SCIPaddSquareSecant()
999- added argument exprdata to SYMcomputeSymmetryGenerators()
1000- removed SCIPconsNonlinearGetRhs(), SCIPconsNonlinearGetLhs(), SCIPconsNonlinearAddLinearCoef()
1001- removed arguments timelimit, minimprove, itercontingent, and iterused from SCIPapplyHeurSubNlp()
1002- removed SCIPresolveSolHeurSubNlp(), SCIPgetSubScipHeurSubNlp(), SCIPgetVarMappingScip2SubScipHeurSubNlp(), SCIPgetVarMappingSubScip2ScipHeurSubNlp()
1003- SCIPlockVarCons() and SCIPunlockVarCons() are now allowed in stage TRANSFORMED as well
1004- Added functions SCIPsetSepaIsParentsepa(), SCIPsetSepaParentsepa() [in scip_sepa.h], SCIPsepaSetIsParentsepa(), SCIPsepaSetParentsepa() [in sepa.h],
1005 SCIPsepaIsParentsepa(), SCIPsepaGetParentsepa() [in pub_sepa.h]
1006- Added function SCIPpruneTree() to immediately delete nodes that were marked to be deleted with SCIPcutoffNode
1009- SCIPhasNLPContinuousNonlinearity() now returns SCIP_RETCODE and has additional argument result
1010- removed SCIPnlrowGetNQuadVars(), SCIPnlrowGetQuadVars(), SCIPnlrowSearchQuadVar(), SCIPnlrowGetNQuadElems(), SCIPnlrowGetQuadElems(), SCIPnlrowGetQuadData()
1011- renamed SCIPnlrowGetExprtree() to SCIPnlrowGetExpr() and changed return type to SCIP_EXPR*
1012- removed arguments nquadvars, quadvars, nquadelems, quadelems from SCIPcreateNlRow(); argument expr(ession) is now of type SCIP_EXPR*
1013- removed SCIPaddQuadVarToNlRow(), SCIPaddQuadVarsToNlRow(), SCIPaddQuadElementToNlRow(), SCIPaddQuadElementsToNlRow(), SCIPchgNlRowQuadElement(), SCIPsetNlRowExprtreeParam(), SCIPsetNlRowExprtreeParams()
1014- renamed SCIPsetNlRowExprtree() to SCIPsetNlRowExpr() and changed type of expr(tree) argument to SCIP_EXPR*
1015- SCIPenableNLP() is no longer allowed in stages INITSOLVE and SOLVING
1016- removed SCIPaddLinearConsToNlpHeurSubNlp()
1017- SCIPhasNLPSolution() now returns true also if a infeasible solution to the NLP exists; SCIPcreateNLPSol() can now also be used when only an infeasible solution to the NLP exists
1018- renamed SCIPsolveNLP() to SCIPsolveNLPParam() and added parameter SCIP_NLPPARAM param
1019- removed SCIPsolveDiveNLP(), use SCIPsolveNLPParam() instead
1022- removed SCIPnlpiCopy(), SCIPnlpiFree(), SCIPnlpiChgQuadCoefs(), SCIPnlpiChgNonlinCoef(), SCIPnlpiSetMessageHdlr()
1023- removed SCIPnlpiCreate() from public API, use SCIPincludeNlpi() instead
1024- removed SCIPnlpiGetSolverPointer() from public API, use SCIPgetNlpiSolverPointer() instead
1025- removed SCIPnlpiCreateProblem() from public API, use SCIPcreateNlpiProblem() instead
1026- removed SCIPnlpiFreeProblem() from public API, use SCIPfreeNlpiProblem() instead
1027- removed SCIPnlpiGetProblemPointer() from public API, use SCIPgetNlpiProblemPointer() instead
1028- removed SCIPnlpiAddVars() from public API, use SCIPaddNlpiVars() instead
1029- removed SCIPnlpiAddConstraints() from public API, use SCIPaddNlpiConstraints() instead
1030- removed SCIPnlpiSetObjective() from public API, use SCIPsetNlpiObjective() instead
1031- removed SCIPnlpiChgVarBounds() from public API, use SCIPchgNlpiVarBounds() instead
1032- removed SCIPnlpiChgConsSides() from public API, use SCIPchgNlpiConsSides() instead
1033- removed SCIPnlpiDelVarSet() from public API, use SCIPdelNlpiVarSet() instead
1034- removed SCIPnlpiDelConsSet() from public API, use SCIPdelNlpiConsSet() instead
1035- removed SCIPnlpiChgLinearCoefs() from public API, use SCIPchgNlpiLinearCoefs() instead
1036- removed SCIPnlpiChgExprtree() from public API, use SCIPchgNlpiExpr() instead
1037- removed SCIPnlpiChgObjConstant() from public API, use SCIPchgNlpiObjConstant() instead
1038- removed SCIPnlpiSetInitialGuess() from public API, use SCIPsetNlpiInitialGuess() instead
1039- removed SCIPnlpiSolve() from public API, use SCIPsolveNlpiParam() instead
1040- removed SCIPnlpiGetSolstat() from public API, use SCIPgetNlpiSolstat() instead
1041- removed SCIPnlpiGetTermstat() from public API, use SCIPgetNlpiTermstat() instead
1042- removed SCIPnlpiGetSolution() from public API, use SCIPgetNlpiSolution() instead
1043- removed SCIPnlpiGetStatistics() from public API, use SCIPgetNlpiStatistics() instead
1044- removed SCIPnlpiGetWarmstartSize()
1045- removed SCIPnlpiGetWarmstartMemo()
1046- removed SCIPnlpiSetWarmstartMemo()
1047- removed SCIPnlpiGetIntPar()
1048- removed SCIPnlpiSetIntPar()
1049- removed SCIPnlpiGetRealPar()
1050- removed SCIPnlpiSetRealPar()
1051- removed SCIPnlpiGetStringPar(),
1052- removed SCIPnlpiSetStringPar()
1053- removed SCIPnlpiSetPriority() from public API, use SCIPsetNlpiPriority() instead
1054- removed argument nlpi from SCIPincludeNlpi() and added name, description, priority,
1055 nlpicopy, nlpifree, nlpigetsolverpointer, nlpicreateproblem, nlpifreeproblem, nlpigetproblempointer, nlpiaddvars, nlpiaddconstraints, nlpisetobjective, nlpichgvarbounds, nlpichgconssides, nlpidelvarset, nlpidelconsset, nlpichglinearcoefs, nlpichgexpr, nlpichgobjconstant, nlpisetinitialguess, nlpisolve, nlpigetsolstat, nlpigettermstat, nlpigetsolution, nlpigetstatistics, nlpidata
1056- removed SCIPcreateNlpSolverAll(), use SCIPincludeNlpSolverAll() instead
1057- removed SCIPcreateNlpSolverFilterSQP(), use SCIPincludeNlpSolverFilterSQP() instead
1058- removed SCIPcreateNlpSolverIpopt(), use SCIPincludeNlpSolverIpopt() instead
1059- removed SCIPcreateNlpSolverWorhp(), use SCIPincludeNlpSolverWorhp() instead
1060- replaced argument BMS_BLKMEM* blkmem of SCIPnlpiOracleCreate() by SCIP* scip
1061- added argument SCIP* scip to SCIPnlpiOracleFree(), SCIPnlpiOracleSetProblemName(), SCIPnlpiOracleAddVars(), SCIPnlpiOracleAddConstraints(), SCIPnlpiOracleSetObjective(), SCIPnlpiOracleChgVarBounds(), SCIPnlpiOracleChgConsSides(), SCIPnlpiOracleDelVarSet(), SCIPnlpiOracleDelConsSet(), SCIPnlpiOracleChgLinearCoefs(), SCIPnlpiOracleChgObjConstant(), SCIPnlpiOracleGetEvalCapability(), SCIPnlpiOracleEvalObjectiveValue(), SCIPnlpiOracleEvalConstraintValue(), SCIPnlpiOracleEvalConstraintValues(), SCIPnlpiOracleEvalObjectiveGradient(), SCIPnlpiOracleEvalConstraintGradient(), SCIPnlpiOracleGetJacobianSparsity(), SCIPnlpiOracleEvalJacobian(), SCIPnlpiOracleGetHessianLagSparsity(), SCIPnlpiOracleEvalHessianLag(), SCIPnlpiOraclePrintProblem(), SCIPnlpiOraclePrintProblemGams()
1062- removed arguments nquadelems, quadelems, exprvaridxs, exprtrees from SCIPnlpiOracleAddConstraints(), added argument SCIP_EXPR** exprs
1063- removed arguments nquadelems, quadelems, exprvaridxs, exprtree from SCIPnlpiOracleSetObjective(), added argument SCIP_EXPR* expr
1064- replaced arguments isnewx of SCIPnlpiOracleEvalHessianLag() by two arguments isnewx_obj and isnewx_cons
1065- removed SCIPnlpiOracleChgExprtree(), use SCIPnlpiOracleChgExpr() instead
1066- removed SCIPnlpiOracleSetInfinity(), SCIPnlpiOracleGetInfinity(), SCIPnlpiOracleChgQuadCoefs(), SCIPnlpiOracleChgExprParam(), SCIPnlpiOracleGetMaxDegree()
1067- removed SCIPnlpiOracleGetVarDegree() and SCIPnlpiOracleGetVarDegrees(), use SCIPnlpiOracleIsVarNonlinear() and SCIPnlpiOracleGetVarCounts(), respectively, instead
1068- removed SCIPnlpiOracleGetConstraintDegree(), use SCIPnlpiOracleIsConstraintNonlinear() instead
1069- removed argument messagehdlr from SCIPnlpiOraclePrintProblem() and SCIPnlpiOraclePrintProblemGams()
1070- removed SCIPcreateNlpiProb(), use SCIPcreateNlpiProblemFromNlRows() instead
1071- renamed SCIPupdateNlpiProb() to SCIPupdateNlpiProblem() and moved into scip_nlpi.{h,c}
1072- renamed SCIPaddNlpiProbRows() to SCIPaddNlpiProblemRows() and moved into scip_nlpi.{h,c}
1073- removed SCIPsetModifiedDefaultSettingsIpopt()
1074- removed SCIPgetIpoptApplicationPointerIpopt(), use SCIPgetNlpiSolverPointer() instead
1075- removed SCIPnlpStatisticsCreate(), SCIPnlpStatisticsFree(), SCIPnlpStatisticsGetNIterations(), SCIPnlpStatisticsGetTotalTime(), SCIPnlpStatisticsSetNIterations(), SCIPnlpStatisticsSetTotalTime(), the struct is public now
1076- renamed LapackDsyev() to SCIPcallLapackDsyevIpopt()
1077- renamed SCIPsolveLinearProb() to SCIPsolveLinearEquationsIpopt()
1079Expression interpreter:
1080- removed functions that operated with SCIPInterval
1081- changed first argument of SCIPexprintCreate() to SCIP*
1082- added SCIP* as first argument to SCIPexprintFree()
1083- added SCIP* as first argument to SCIPexprintCompile(), changed third argument to SCIP_EXPR*, added fourth argument SCIP_EXPRINTDATA**
1084- added arguments SCIP*, SCIP_EXPRINT*, and SCIP_EXPR* as first arguments to SCIPexprintFreeData()
1085- renamed SCIPexprintGetExprtreeCapability() to SCIPexprintGetExprCapability();
1086 added SCIP* as first argument, changed third argument to SCIP_EXPR*, added fourth argument SCIP_EXPRINTDATA*
1087- removed SCIPexprintNewParametrization()
1088- SCIPexprintEval(): added SCIP* as first argument, changed third argument to SCIP_EXPR*, added fourth argument SCIP_EXPRINTDATA*
1089- removed SCIPexprintEvalInt()
1090- SCIPexprintGrad(): added SCIP* as first argument, changed third argument to SCIP_EXPR*, added fourth argument SCIP_EXPRINTDATA*
1091- removed SCIPexprintGradInt()
1092- removed SCIPexprintHessianSparsityDense() and SCIPexprintHessianDense, use SCIPexprintHessianSparsity() and SCIPexprintHessian() instead
1095- removed SCIPexpropGetName(), use SCIPexprhdlrGetName() instead
1096- removed SCIPexpropGetNChildren()
1097- removed SCIPexprGetOperator(), use SCIPexprGetHdlr() instead
1098- removed SCIPexprGetOpIndex(), SCIPexprGetOpReal(), SCIPexprGetOpData(), use SCIPexprGetData() instead
1099- removed SCIPexprGetRealPowerExponent(), SCIPexprGetIntPowerExponent(), SCIPexprGetSignPowerExponent(), use SCIPgetExponentExprPow() instead
1100- removed SCIPexprGetLinearCoefs(), SCIPexprGetLinearConstant(), use SCIPgetCoefsExprSum() and SCIPgetConstantExprSum() instead
1101- removed SCIPexprGetQuadElements(), SCIPexprGetQuadConstant(), SCIPexprGetQuadLinearCoefs(), SCIPexprGetNQuadElements(), use SCIPexprGetQuadraticData(), SCIPexprGetQuadraticQuadTerm(), SCIPexprGetQuadraticBilinTerm() instead
1102- removed SCIPexprGetMonomials(), SCIPexprGetNMonomials, SCIPexprGetPolynomialConstant(), SCIPexprGetMonomialCoef(), SCIPexprGetMonomialNFactors(), SCIPexprGetMonomialChildIndices(), SCIPexprGetMonomialExponents()
1103- removed SCIPexprGetUserData(), SCIPexprHasUserEstimator(), SCIPexprGetUserEvalCapability()
1104- removed SCIPexprCreate(), use SCIPcreateExpr() instead
1105- removed SCIPexprCopyDeep(), use SCIPduplicateExpr() instead
1106- removed SCIPexprFreeDeep(), use SCIPreleaseExpr() instead
1107- removed SCIPexprFreeShallow()
1108- removed SCIPexprAdd(), SCIPexprMulConstant()
1109- removed SCIPexprCreateLinear(), use SCIPcreateExprSum() instead
1110- replaced SCIPexprAddToLinear() by SCIPappendExprSumExpr()
1111- replaced SCIPexprCreateQuadratic() by SCIPcreateExprQuadratic()
1112- removed SCIPexprSortQuadElems()
1113- removed SCIPexprCreatePolynomial(), SCIPexprAddMonomials(), SCIPexprChgPolynomialConstant(), SCIPexprMultiplyPolynomialByConstant(), SCIPexprMultiplyPolynomialByMonomial(), SCIPexprMultiplyPolynomialByPolynomial(), SCIPexprPolynomialPower()
1114- removed SCIPexprMergeMonomials(), SCIPexprFreeMonomial(), SCIPexprSortMonomialFactors(), SCIPexprFindMonomialFactor(), SCIPexprAreMonomialsEqual(), SCIPexprAddMonomialFactors(), SCIPexprChgMonomialCoef(), SCIPexprMultiplyMonomialByMonomial(), SCIPexprMonomialPower(), SCIPexprMergeMonomialFactors(), SCIPexprSortMonomials()
1115- replaced SCIPexprCreateMonomial() by SCIPcreateExprMonomial()
1116- removed SCIPexprCreateUser(), use SCIPincludeExprhdlr() instead
1117- removed SCIPexprHasParam(), SCIPexprGetMaxDegree(), SCIPexprGetVarsUsage()
1118- replaced SCIPexprAreEqual() by SCIPcompareExpr()
1119- replaced SCIPexprSimplify() by SCIPsimplifyExpr()
1120- replaced SCIPexprEvalShallow() by SCIPcallExprEval()
1121- replaced SCIPexprEval() by SCIPevalExpr()
1122- replaced SCIPexprEvalIntShallow() by SCIPcallExprInteval()
1123- replaced SCIPexprEvalInt() by SCIPevalExprActivity()
1124- removed SCIPexprEvalUser(), SCIPexprEvalIntUser(), SCIPexprEstimateUser()
1125- replaced SCIPexprCheckCurvature() by SCIPcomputeExprCurvature()
1126- removed SCIPexprSubstituteVars(), use SCIPcopyExpr() instead
1127- removed SCIPexprReindexVars(), SCIPexprReindexParams()
1128- replaced SCIPexprPrint() by SCIPprintExpr()
1129- replaced SCIPexprParse() by SCIPparseExpr()
1132- removed SCIPexprtreeGetVars(), SCIPexprtreeSetVars(), SCIPexprtreeAddVars(), SCIPexprtreePrintWithNames(), SCIPexprtreeFindVar()
1133- removed SCIPexprtreeGetRoot(), SCIPexprtreeGetNVars(), SCIPexprtreeGetNParams(), SCIPexprtreeGetParamVals(), SCIPexprtreeSetParamVal(), SCIPexprtreeHasParam()
1134- removed SCIPexprtreeGetInterpreterData(), SCIPexprtreeSetInterpreterData(), SCIPexprtreeFreeInterpreterData()
1135- removed SCIPexprtreeGetMaxDegree()
1136- removed SCIPexprtreeEval(), use SCIPevalExpr() instead
1137- removed SCIPexprtreeEvalInt(), use SCIPevalExprActivity() instead
1138- removed SCIPexprtreePrint(), use SCIPprintExpr() instead
1139- removed SCIPexprtreeCreate()
1140- removed SCIPexprtreeCopy(), use SCIPduplicateExpr() instead
1141- removed SCIPexprtreeFree(), use SCIPreleaseExpr() instead
1142- removed SCIPexprtreeSetParams(), SCIPexprtreeGetVarsUsage()
1143- removed SCIPexprtreeSimplify(), use SCIPsimplifyExpr() instead
1144- removed SCIPexprtreeAddExpr()
1145- removed SCIPexprtreeCheckCurvature(), use SCIPcomputeExprCurvature() instead
1146- removed SCIPexprtreeSubstituteVars(), use SCIPcopyExpr() instead
1147- removed SCIPquadelemSort(), SCIPquadelemSortedFind(), SCIPquadelemSqueeze()
1150- removed SCIPexprgraphCaptureNode(), use SCIPcaptureExpr() instead
1151- removed SCIPexprgraphIsNodeEnabled()
1152- removed SCIPexprgraphGetNodeNChildren(), use SCIPexprGetNChildren() instead
1153- removed SCIPexprgraphGetNodeChildren(), use SCIPexprGetChildren() instead
1154- removed SCIPexprgraphGetNodeNParents(), SCIPexprgraphGetNodeParents(), SCIPexprgraphGetNodeDepth(), SCIPexprgraphGetNodePosition()
1155- removed SCIPexprgraphGetNodeOperator(), use SCIPexprGetHdlr() instead
1156- removed SCIPexprgraphGetNodeOperatorIndex(), SCIPexprgraphGetNodeOperatorReal(), use SCIPexprGetData() instead
1157- removed SCIPexprgraphGetNodeVar(), use SCIPgetVarExprVar() instead
1158- removed SCIPexprgraphGetNodeRealPowerExponent(), SCIPexprgraphGetNodeIntPowerExponent(), SCIPexprgraphGetNodeSignPowerExponent(), use SCIPgetExponentExprPow() instead
1159- removed SCIPexprgraphGetNodeLinearCoefs(), SCIPexprgraphGetNodeLinearConstant(), use SCIPgetCoefsExprSum(), SCIPgetConstantExprSum() instead
1160- removed SCIPexprgraphGetNodeQuadraticConstant(), SCIPexprgraphGetNodeQuadraticLinearCoefs(), SCIPexprgraphGetNodeQuadraticQuadElements(), SCIPexprgraphGetNodeQuadraticNQuadElements(), use SCIPexprGetQuadraticData(), SCIPexprGetQuadraticQuadTerm(), SCIPexprGetQuadraticBilinTerm() instead
1161- removed SCIPexprgraphGetNodePolynomialMonomials(), SCIPexprgraphGetNodePolynomialNMonomials(), SCIPexprgraphGetNodePolynomialConstant(), SCIPexprgraphGetNodePolynomialMonomialCurvature()
1162- removed SCIPexprgraphGetNodeUserData(), SCIPexprgraphHasNodeUserEstimator()
1163- removed SCIPexprgraphGetNodeBounds(), use SCIPexprGetActivity() instead
1164- removed SCIPexprgraphGetNodeVal(), use SCIPexprGetEvalValue() instead
1165- removed SCIPexprgraphGetNodeCurvature(), use SCIPexprGetCurvature() instead
1166- removed SCIPexprgraphCreateNode()
1167- removed SCIPexprgraphCreateNodeLinear(), use SCIPcreateExprSum() instead
1168- removed SCIPexprgraphCreateNodeQuadratic(), use SCIPcreateExprQuadratic() instead
1169- removed SCIPexprgraphCreateNodePolynomial(), SCIPexprgraphNodePolynomialAddMonomials()
1170- removed SCIPexprgraphCreateNodeUser(), removed SCIPexprgraphNodeSplitOffLinear(), SCIPexprgraphMoveNodeParents()
1171- removed SCIPexprgraphReleaseNode(), use SCIPreleaseExpr() instead
1172- removed SCIPexprgraphFreeNode(), use SCIPreleaseExpr() instead
1173- removed SCIPexprgraphEnableNode(), SCIPexprgraphDisableNode()
1174- removed SCIPexprgraphHasNodeSibling(), SCIPexprgraphAreAllNodeChildrenVars(), SCIPexprgraphHasNodeNonlinearAncestor()
1175- removed SCIPexprgraphPrintNode(), SCIPprintExpr() instead
1176- removed SCIPexprgraphTightenNodeBounds()
1177- removed SCIPexprgraphUpdateNodeBoundsCurvature(), use SCIPevalExprActivity() and SCIPcomputeExprCurvature() instead
1178- removed SCIPexprgraphGetDepth(), SCIPexprgraphGetNNodes(), SCIPexprgraphGetNodes(), SCIPexprgraphGetNVars(), SCIPexprgraphGetVars()
1179- removed SCIPexprgraphGetVarNodes(), SCIPexprgraphSetVarNodeValue(), SCIPexprgraphSetVarsBounds(), SCIPexprgraphSetVarBounds(), SCIPexprgraphSetVarNodeBounds(), SCIPexprgraphSetVarNodeLb(), SCIPexprgraphSetVarNodeUb(), SCIPexprgraphGetVarsBounds()
1180- removed SCIPexprgraphCreate(), SCIPexprgraphFree()
1181- removed SCIPexprgraphAddNode(), SCIPexprgraphAddVars(), SCIPexprgraphAddConst(), SCIPexprgraphAddExprtreeSum()
1182- removed SCIPexprgraphReplaceVarByLinearSum(), SCIPexprgraphFindVarNode(), SCIPexprgraphFindConstNode()
1183- replaced SCIPexprgraphPrintDot() by SCIPprintExprDotInit[2](), SCIPprintExprDot(), SCIPprintExprDotFinal()
1184- removed SCIPexprgraphEval(), use SCIPevalExpr() instead
1185- removed SCIPexprgraphPropagateVarBounds(), SCIPexprgraphPropagateNodeBounds()
1186- removed SCIPexprgraphCheckCurvature(), use SCIPcomputeExprCurvature() instead
1187- removed SCIPexprgraphSimplify(), use SCIPsimplifyExpr() instead
1188- removed SCIPexprgraphGetTree(), SCIPexprgraphGetSeparableTrees(), SCIPexprgraphGetSubtreeVarsUsage(), SCIPexprgraphGetSumTreesNSummands(), SCIPexprgraphGetSumTrees()
1190Constraint handlers for NLP:
1191- removed SCIPincludeConshdlrAbspower()
1192- deprecated SCIPcreateConsAbspower() and SCIPcreateConsBasicAbspower(), use SCIPcreateConsBasicSignpowerNonlinear() instead
1193- deprecated SCIPgetNlRowAbspower(), use SCIPgetNlRowNonlinear() instead
1194- removed SCIPgetNonlinearVarAbspower(), SCIPgetLinearVarAbspower(), SCIPgetExponentAbspower(), SCIPgetOffsetAbspower(), SCIPgetCoefLinearAbspower(), SCIPgetLhsAbspower(), SCIPgetRhsAbspower()
1195- removed SCIPgetViolationAbspower(), use SCIPgetAbsViolationNonlinear() instead
1196- removed SCIPisConvexAbspower(), use SCIPhasExprCurvature() instead
1197- removed SCIPincludeConshdlrBivariate(), SCIPcreateConsBivariate(), SCIPcreateConsBasicBivariate()
1198- removed SCIPgetLinearVarBivariate(), SCIPgetLinearCoefBivariate(), SCIPgetExprtreeBivariate(), SCIPgetLhsBivariate(), SCIPgetRhsBivariate()
1199- removed SCIPincludeConshdlrQuadratic(), use SCIPincludeNlhdlrQuadratic() instead
1200- removed SCIPincludeQuadconsUpgrade()
1201- removed SCIPcreateConsQuadratic2(), SCIPcreateConsBasicQuadratic2()
1202- deprecated SCIPcreateConsBasicQuadratic(), use SCIPcreateConsBasicQuadraticNonlinear() instead
1203- deprecated SCIPcreateConsBasicQuadratic(), use SCIPcreateConsQuadraticNonlinear() instead
1204- deprecated SCIPaddConstantQuadratic(), use SCIPgetLhsNonlinear() and SCIPgetRhsNonlinear() instead
1205- deprecated SCIPaddLinearVarQuadratic(), use SCIPaddLinearVarNonlinear() instead
1206- deprecated SCIPaddQuadVarQuadratic(), use SCIPaddLinearVarNonlinear() and SCIPaddExprNonlinear() instead
1207- deprecated SCIPaddQuadVarLinearCoefQuadratic(), use SCIPaddLinearVarNonlinear() instead
1208- deprecated SCIPaddSquareCoefQuadratic(), use SCIPaddExprNonlinear() instead
1209- deprecated SCIPaddBilinTermQuadratic(), use SCIPaddExprNonlinear() instead
1210- deprecated SCIPchgLhsQuadratic(), use SCIPgetLhsNonlinear() instead
1211- deprecated SCIPchgRhsQuadratic(), use SCIPgetRhsNonlinear() instead
1212- deprecated SCIPgetNlRowQuadratic(), use SCIPgetNlRowNonlinear() instead
1213- removed SCIPgetNLinearVarsQuadratic(), SCIPgetLinearVarsQuadratic(), SCIPgetCoefsLinearVarsQuadratic(), SCIPgetNQuadVarTermsQuadratic(), SCIPgetQuadVarTermsQuadratic(), SCIPsortQuadVarTermsQuadratic(), SCIPfindQuadVarTermQuadratic(), SCIPgetNBilinTermsQuadratic(), SCIPgetBilinTermsQuadratic(), SCIPgetLhsQuadratic(), SCIPgetRhsQuadratic()
1214- removed SCIPgetLinvarMayDecreaseQuadratic(), SCIPgetLinvarMayIncreaseQuadratic()
1215- removed SCIPcheckCurvatureQuadratic() and SCIPisConvexConsQuadratic(), use SCIPcomputeExprQuadraticCurvature() instead
1216- removed SCIPisConvexQuadratic(), SCIPisConcaveQuadratic()
1217- removed SCIPgetViolationQuadratic() and SCIPgetFeasibilityQuadratic(), use SCIPgetAbsViolationNonlinear() instead
1218- removed SCIPisLinearLocalQuadratic(), SCIPaddToNlpiProblemQuadratic()
1219- removed SCIPchgLinearCoefQuadratic(), SCIPchgSquareCoefQuadratic(), SCIPchgBilinCoefQuadratic()
1220- renamed SCIPgetNAllBilinearTermsQuadratic() to SCIPgetNBilinTermsNonlinear() and changed argument from SCIP* to SCIP_CONSHDLR*
1221- renamed SCIPgetAllBilinearTermsQuadratic() to SCIPgetBilinTermsNonlinear() and replaced arguments by SCIP_CONSHDLR* and changed return type to SCIP_CONSNONLINEAR_BILINTERM*
1222- removed SCIPaddBilinearIneqQuadratic(), use SCIPinsertBilinearTermImplicitNonlinear() instead
1223- renamed SCIPcreateConsQuadratic() to SCIPcreateConsQuadraticNonlinear() and removed argument stickingatnode
1224- removed SCIPincludeConshdlrSOC()
1225- replaced SCIPcreateConsBasicSOC() by SCIPcreateConsBasicSOCNonlinear()
1226- deprecated SCIPcreateConsSOC(), use SCIPcreateConsBasicSOCNonlinear() instead
1227- deprecated SCIPgetNlRowSOC(), use SCIPgetNlRowNonlinear() instead
1228- removed SCIPgetNLhsVarsSOC(), SCIPgetLhsVarsSOC(), SCIPgetLhsCoefsSOC(), SCIPgetLhsOffsetsSOC(), SCIPgetLhsConstantSOC(), SCIPgetRhsVarSOC(), SCIPgetRhsCoefSOC(), SCIPgetRhsOffsetSOC(), use SCIPisSOCNonlinear() instead
1229- removed SCIPaddToNlpiProblemSOC()
1230- renamed SCIPincludeNonlinconsUpgrade() to SCIPincludeConsUpgradeNonlinear() and removed nodereform argument
1231- removed arguments nlinvars, linvars, lincoefs, nexprtrees, exprtrees, nonlincoefs, stickingatnode from SCIPcreateConsNonlinear() and added SCIP_EXPR* argument
1232- removed arguments nlinvars, linvars, lincoefs, nexprtrees, exprtrees, nonlincoefs from SCIPcreateConsBasicNonlinear() and added SCIP_EXPR* argument
1233- removed SCIPcreateConsNonlinear2(), SCIPcreateConsBasicNonlinear2()
1234- removed SCIPsetExprtreesNonlinear(), use SCIPchgExprNonlinear() instead
1235- removed SCIPaddExprtreesNonlinear()
1236- removed SCIPgetNLinearVarsNonlinear(), SCIPgetLinearVarsNonlinear(), SCIPgetLinearCoefsNonlinear()
1237- removed SCIPgetNExprtreesNonlinear(), SCIPgetExprtreesNonlinear(), SCIPgetExprtreeCoefsNonlinear(), SCIPgetExprgraphNodeNonlinear(), use SCIPgetExprNonlinear() instead
1238- removed argument scip from SCIPgetLhsNonlinear() and SCIPgetRhsNonlinear()
1239- removed SCIPcheckCurvatureNonlinear(), SCIPgetCurvatureNonlinear(), and SCIPgetExprtreeCurvaturesNonlinear(), use SCIPhasExprCurvature() instead
1240- renamed SCIPgetViolationNonlinear() to SCIPgetAbsViolationNonlinear()
1241- added arguments var and coef to SCIPgetLinvarMayDecreaseNonlinear() and SCIPgetLinvarMayIncreaseNonlinear() and changed return type to void
1242- removed SCIPgetExprgraphNonlinear()
1243- removed SCIPcomputeHyperplaneThreePoints(), use SCIPcomputeFacetVertexPolyhedralNonlinear() instead
1245### New API functions
1247- added SCIPallocClearMemory() and SCIPallocClearBlockMemory() to allocate a chunk of (block) memory
1248 that is initialized to zeros
1249- New internal functions for changing the default values of parameters:
1250 SCIPparamsetSetDefaultLongint(), SCIPparamsetSetDefaultReal(), SCIPparamsetSetDefaultChar(),
1251 SCIPparamsetSetDefaultString() and
1252 SCIPparamSetDefaultLongint(), SCIPparamSetDefaultReal(), SCIPparamSetDefaultChar(),
1253 SCIPparamSetDefaultString()
1254- new internal function SCIPisPackingPartitioningOrbitope() to check whether an orbitope is of
1255 packing or partitioning type
1256- new internal function SCIPcomputeOrbitVar() to compute the symmetry orbit of a variable
1257- added SCIPcalcFibHash(SCIP_Real) to hash a floating-point value to an unsigned integer
1258- added SCIPcomputeArraysIntersectionPtr() to compute intersection of two sorted arrays of pointers
1259- new function SCIPinterruptLP() (intended to be called from a different thread) that interrupts ongoing lp solve
1260- added SCIPcreateConsIndicatorGeneric() and SCIPcreateConsIndicatorGenericLinCons()
1261 which copy the interface of SCIPcreateConsIndicator() and SCIPcreateConsIndicatorLinCons() and
1262 add an activeone argument to specify whether the indicator constraint should be activated on 0 or 1.
1263 SCIPcreateConsIndicator() also adds a lessthanineq flag to choose whether the linear constraint is a less-than or greater-than inequality.
1264- added SCIPmarkDoNotAggrVar() to mark that a variable should not be aggregated
1265- added SCIPdoNotAggrVar() to query whether a variable should not be aggregated
1266- added SCIPdecompGetNBorderVars() and SCIPdecompGetNBorderConss() to get number of border variables/constraints
1267- added SCIPdecompGetVarsSize() and SCIPdecompGetConssSize() to get variable/constraint size for each block of a decomposition
1268- added SCIPincludeDialogDefaultBasic()
1269- added SCIPintervalAreDisjointEps(), SCIPintervalIntersectEps()
1270- added SCIPintervalEntropy()
1271- added SCIPintervalPropagateWeightedSum()
1272- added SCIPcalcRootNewton()
1273- added SCIPvarGetImplicVarBounds()
1274- added SCIPcreateRowprep(), SCIPfreeRowprep(), SCIPcopyRowprep(),
1275 SCIProwprepGetNVars(), SCIProwprepGetVars(), SCIProwprepGetCoefs(), SCIProwprepGetSide(), SCIProwprepGetSidetype(), SCIProwprepIsLocal(), SCIProwprepGetName(), SCIProwprepGetNModifiedVars(), SCIProwprepGetModifiedVars(),
1276 SCIProwprepReset(), SCIProwprepAddSide(), SCIProwprepAddConstant(), SCIProwprepSetSidetype(), SCIProwprepSetLocal(), SCIProwprepRecordModifications(),
1277 SCIPprintRowprep(), SCIPprintRowprepSol(), SCIPensureRowprepSize(), SCIPaddRowprepTerm(), SCIPaddRowprepTerms(), SCIPgetRowprepViolation(), SCIPisRowprepViolationReliable(),
1278 SCIPmergeRowprepTerms(), SCIPcleanupRowprep(), SCIPcleanupRowprep2(), SCIPscaleupRowprep(), SCIPscaleRowprep(),
1279 SCIPgetRowprepRowConshdlr(), SCIPgetRowprepRowCons(), SCIPgetRowprepRowSepa()
1280- added SCIPsetClockEnabled()
1281- added SCIPisSolveInterrupted() to check whether SCIPinterruptSolve() has been called
1282- added SCIPgetNPresolRounds()
1283- added SCIPgetNUnfixedLPCols()
1284- moved SCIPhistoryGetInferenceSum() and SCIPhistoryGetAvgConflictlength() from internal to public API
1287- added SCIPincludeExprhdlr(), SCIPgetExprhdlrs(), SCIPgetNExprhdlrs(), SCIPfindExprhdlr()
1288- added SCIPgetExprhdlrVar(), SCIPgetExprhdlrValue(), SCIPgetExprhdlrSum(), SCIPgetExprhdlrProduct(), SCIPgetExprhdlrPower()
1289- added SCIPexprhdlrSetCopyFreeHdlr(), SCIPexprhdlrSetCopyFreeData(), SCIPexprhdlrSetPrint(), SCIPexprhdlrSetParse(), SCIPexprhdlrSetCurvature(), SCIPexprhdlrSetMonotonicity(), SCIPexprhdlrSetIntegrality(), SCIPexprhdlrSetHash(), SCIPexprhdlrSetCompare(), SCIPexprhdlrSetDiff(), SCIPexprhdlrSetIntEval(), SCIPexprhdlrSetSimplify(), SCIPexprhdlrSetReverseProp(), SCIPexprhdlrSetEstimate()
1290- added SCIPexprhdlrGetName(), SCIPexprhdlrGetDescription(), SCIPexprhdlrGetPrecedence(), SCIPexprhdlrGetData(), SCIPexprhdlrHasPrint(), SCIPexprhdlrHasBwdiff(), SCIPexprhdlrHasFwdiff(), SCIPexprhdlrHasIntEval(), SCIPexprhdlrHasEstimate(), SCIPexprhdlrHasInitEstimates(), SCIPexprhdlrHasSimplify(), SCIPexprhdlrHasCurvature(), SCIPexprhdlrHasMonotonicity(), SCIPexprhdlrHasReverseProp()
1291- added SCIPexprhdlrComp()
1292- added SCIPexprhdlrGetNIntevalCalls(), SCIPexprhdlrGetIntevalTime(), SCIPexprhdlrGetNReversepropCalls(), SCIPexprhdlrGetReversepropTime(), SCIPexprhdlrGetNCutoffs(), SCIPexprhdlrGetNDomainReductions(), SCIPexprhdlrIncrementNDomainReductions(), SCIPexprhdlrGetNEstimateCalls(), SCIPexprhdlrGetEstimateTime(), SCIPexprhdlrGetNBranchings(), SCIPexprhdlrIncrementNBranchings(), SCIPexprhdlrGetNSimplifyCalls(), SCIPexprhdlrGetSimplifyTime(), SCIPexprhdlrGetNSimplifications()
1293- added SCIPprintExpressionHandlerStatistics()
1294- added SCIPincludeExprhdlrEntropy(), SCIPcreateExprEntropy(), SCIPisExprEntropy()
1295- added SCIPincludeExprhdlrErf(), SCIPcreateExprErf(), SCIPisExprErf()
1296- added SCIPcreateExprAbs(), SCIPincludeExprhdlrAbs(), SCIPisExprAbs()
1297- added SCIPcreateExprExp(), SCIPincludeExprhdlrExp(), SCIPisExprExp()
1298- added SCIPcreateExprLog(), SCIPincludeExprhdlrLog(), SCIPisExprLog()
1299- added SCIPcreateExprPow(), SCIPcreateExprSignpower(), SCIPincludeExprhdlrPow(), SCIPincludeExprhdlrSignpower(), SCIPisExprSignpower(), SCIPgetExponentExprPow(), SCIPisExprPower()
1300- added SCIPincludeExprhdlrProduct(), SCIPcreateExprProduct(), SCIPgetCoefExprProduct(), SCIPisExprProduct()
1301- added SCIPincludeExprhdlrSum(), SCIPcreateExprSum(), SCIPsetConstantExprSum(), SCIPappendExprSumExpr(), SCIPmultiplyByConstantExprSum(), SCIPgetCoefsExprSum(), SCIPgetConstantExprSum(), SCIPisExprSum()
1302- added SCIPincludeExprhdlrSin(), SCIPcreateExprSin(), SCIPincludeExprhdlrCos(), SCIPcreateExprCos(), SCIPisExprSin(), SCIPisExprCos()
1303- added SCIPincludeExprhdlrValue(), SCIPcreateExprValue(), SCIPgetValueExprValue(), SCIPisExprValue()
1304- added SCIPincludeExprhdlrVar(), SCIPcreateExprVar(), SCIPgetVarExprVar(), SCIPisExprVar()
1305- added SCIPincludeExprhdlrVaridx(), SCIPcreateExprVaridx(), SCIPisExprVaridx(), SCIPgetIndexExprVaridx(), SCIPsetIndexExprVaridx()
1308- added SCIPcaptureExpr(), SCIPreleaseExpr(), SCIPexprGetNUses()
1309- added SCIPexprGetHdlr(), SCIPexprGetData(), SCIPexprSetData(), SCIPexprGetOwnerData()
1310- added SCIPevalExpr(), SCIPgetExprNewSoltag(), SCIPexprGetEvalValue(), SCIPexprGetEvalTag()
1311- added SCIPevalExprGradient(), SCIPevalExprHessianDir(), SCIPexprGetDerivative(), SCIPexprGetDot(), SCIPexprGetBardot(), SCIPexprGetDiffTag()
1312- added SCIPevalExprActivity(), SCIPexprGetActivity(), SCIPexprGetActivityTag(), SCIPexprSetActivity()
1313- added SCIPcomputeExprCurvature(), SCIPexprGetCurvature(), SCIPexprSetCurvature()
1314- added SCIPcomputeExprIntegrality(), SCIPexprIsIntegral(), SCIPexprSetIntegrality()
1315- added SCIPcheckExprQuadratic(), SCIPfreeExprQuadratic(), SCIPevalExprQuadratic(), SCIPprintExprQuadratic(), SCIPcomputeExprQuadraticCurvature()
1316- added SCIPexprGetQuadraticData(), SCIPexprGetQuadraticQuadTerm(), SCIPexprGetQuadraticBilinTerm(), SCIPexprAreQuadraticExprsVariables()
1317- added SCIPcreateExpr(), SCIPcreateExpr2(), SCIPcreateExprQuadratic(), SCIPcreateExprMonomial()
1318- added SCIPappendExprChild(), SCIPreplaceExprChild(), SCIPremoveExprChildren()
1319- added SCIPduplicateExpr(), SCIPduplicateExprShallow(), SCIPcopyExpr()
1320- added SCIPparseExpr()
1321- added SCIPprintExpr(), SCIPdismantleExpr()
1322- added SCIPprintExprDotInit(), SCIPprintExprDotInit2(), SCIPprintExprDot(), SCIPprintExprDotFinal(), SCIPshowExpr()
1323- added SCIPcompareExpr(), SCIPhashExpr()
1324- added SCIPsimplifyExpr(), SCIPreplaceCommonSubexpressions()
1325- added SCIPgetExprNVars(), SCIPgetExprVarExprs()
1326- added SCIPcallExprPrint(), SCIPcallExprCurvature(), SCIPcallExprMonotonicity(), SCIPcallExprEval(), SCIPcallExprEvalFwdiff(), SCIPcallExprInteval(), SCIPcallExprEstimate(), SCIPcallExprInitestimates(), SCIPcallExprSimplify(), SCIPcallExprReverseprop()
1327- added SCIPexprcurvPowerInv(), SCIPexprcurvMonomialInv()
1330- added SCIPcreateExpriter(), SCIPfreeExpriter()
1331- added SCIPexpriterIsInit(), SCIPexpriterInit()
1332- added SCIPexpriterRestartDFS(), SCIPexpriterSetStagesDFS(), SCIPexpriterGetCurrent(), SCIPexpriterGetStageDFS(), SCIPexpriterGetChildIdxDFS(), SCIPexpriterGetChildExprDFS(), SCIPexpriterGetParentDFS()
1333- added SCIPexpriterGetCurrentUserData(), SCIPexpriterGetChildUserDataDFS(), SCIPexpriterGetExprUserData(), SCIPexpriterSetCurrentUserData(), SCIPexpriterSetExprUserData(), SCIPexpriterSetChildUserData()
1334- added SCIPexpriterGetNext(), SCIPexpriterSkipDFS(), SCIPexpriterIsEnd()
1335- added SCIPexprintHessianSparsity(), SCIPexprintHessian()
1337Constraint handlers for NLP:
1338- added SCIPgetCurBoundsTagNonlinear(), SCIPgetLastBoundRelaxTagNonlinear(), SCIPincrementCurBoundsTagNonlinear()
1339- added SCIPgetVarExprHashmapNonlinear()
1340- added SCIPprocessRowprepNonlinear()
1341- added SCIPassumeConvexNonlinear()
1342- added SCIPcollectBilinTermsNonlinear(), SCIPgetBilinTermIdxNonlinear(), SCIPgetBilinTermNonlinear(), SCIPevalBilinAuxExprNonlinear(), SCIPinsertBilinearTermExistingNonlinear(), SCIPinsertBilinearTermImplicitNonlinear()
1343- added SCIPcomputeFacetVertexPolyhedralNonlinear()
1344- added SCIPgetExprNonlinear()
1345- added SCIPcheckQuadraticNonlinear(), SCIPchgLhsNonlinear(), SCIPchgRhsNonlinear(), SCIPchgExprNonlinear(), SCIPaddExprNonlinear()
1346- added SCIPgetRelViolationNonlinear()
1347- added SCIPgetExprNLocksPosNonlinear(), SCIPgetExprNLocksNegNonlinear(), SCIPgetExprAuxVarNonlinear(), SCIPgetExprNEnfosNonlinear(), SCIPgetExprEnfoDataNonlinear(), SCIPsetExprEnfoAuxValueNonlinear()
1348- added SCIPgetExprNPropUsesActivityNonlinear(), SCIPgetExprNSepaUsesActivityNonlinear(), SCIPgetExprNAuxvarUsesNonlinear(), SCIPregisterExprUsageNonlinear()
1349- added SCIPgetExprAbsOrigViolationNonlinear(), SCIPgetExprAbsAuxViolationNonlinear(), SCIPgetExprRelAuxViolationNonlinear()
1350- added SCIPgetExprBoundsNonlinear(), SCIPtightenExprIntervalNonlinear(), SCIPmarkExprPropagateNonlinear()
1351- added SCIPaddExprViolScoreNonlinear(), SCIPaddExprsViolScoreNonlinear(), SCIPgetExprViolScoreNonlinear()
1352- added SCIPgetExprPartialDiffNonlinear(), SCIPgetExprPartialDiffGradientDirNonlinear()
1353- added SCIPevalExprQuadraticAuxNonlinear()
1354- added SCIPincludeNlhdlrNonlinear(), SCIPfindNlhdlrNonlinear(), SCIPgetNNlhdlrsNonlinear(), SCIPgetNlhdlrsNonlinear(), SCIPgetNlhdlrExprDataNonlinear()
1355- added SCIPcreateConsQuadraticNonlinear() and SCIPcreateConsBasicQuadraticNonlinear() to create a nonlinear constraint that is quadratic
1356- added SCIPcreateConsBasicSignpowerNonlinear() to create a nonlinear constraint that looks like the former abspower or signpower constraints
1359- added SCIPincludeNlhdlrBilinear(), SCIPgetExprsBilinear(), SCIPgetExprsdataBilinear(), SCIPgetNExprsBilinear(), SCIPaddIneqBilinear()
1360- added SCIPincludeNlhdlrConvex(), SCIPincludeNlhdlrConcave(), SCIPhasExprCurvature()
1361- added SCIPincludeNlhdlrDefault()
1362- added SCIPincludeNlhdlrPerspective()
1363- added SCIPincludeNlhdlrQuadratic()
1364- added SCIPincludeNlhdlrQuotient()
1365- added SCIPincludeNlhdlrSoc(), SCIPisSOCNonlinear(), SCIPfreeSOCArraysNonlinear()
1366- added SCIPnlhdlrSetCopyHdlr(), SCIPnlhdlrSetFreeHdlrData(), SCIPnlhdlrSetFreeExprData(), SCIPnlhdlrSetInitExit(), SCIPnlhdlrSetProp(), SCIPnlhdlrSetSepa()
1367- added SCIPnlhdlrGetName(), SCIPnlhdlrGetDesc(), SCIPnlhdlrGetDetectPriority(), SCIPnlhdlrGetEnfoPriority(), SCIPnlhdlrIsEnabled(), SCIPnlhdlrGetData()
1368- added SCIPnlhdlrHasIntEval(), SCIPnlhdlrHasReverseProp(), SCIPnlhdlrHasInitSepa(), SCIPnlhdlrHasExitSepa(), SCIPnlhdlrHasEnfo(), SCIPnlhdlrHasEstimate()
1369- added SCIPnlhdlrComp()
1372- added SCIPgetNlpiSolverPointer(), SCIPcreateNlpiProblem(), SCIPfreeNlpiProblem(), SCIPgetNlpiProblemPointer(), SCIPaddNlpiVars(), SCIPaddNlpiConstraints(), SCIPsetNlpiObjective(), SCIPchgNlpiVarBounds(), SCIPchgNlpiConsSides(), SCIPdelNlpiVarSet(), SCIPdelNlpiConsSet(), SCIPchgNlpiLinearCoefs(), SCIPchgNlpiExpr(), SCIPchgNlpiObjConstant(), SCIPsetNlpiInitialGuess(), SCIPsolveNlpiParam(), SCIPgetNlpiSolstat(), SCIPgetNlpiTermstat(), SCIPgetNlpiSolution(), SCIPgetNlpiStatistics()
1373- added SCIPincludeNlpSolverAll()
1374- added SCIPincludeNlpSolverFilterSQP(), SCIPgetSolverNameFilterSQP(), SCIPgetSolverDescFilterSQP(), SCIPisFilterSQPAvailableFilterSQP()
1375- added SCIPincludeNlpSolverIpopt()
1376- added SCIPincludeNlpSolverWorhp()
1377- added SCIPnlpiOracleChgExpr()
1378- added SCIPcreateNlpiProblemFromNlRows()
1379- added SCIPnlpiOracleGetObjectiveConstant()
1380- added SCIPnlpiOracleIsVarNonlinear(), SCIPnlpiOracleGetVarCounts(), SCIPnlpiOracleIsConstraintNonlinear()
1381- added SCIPnlpiGetNProblems(), SCIPnlpiGetProblemTime(), SCIPnlpiGetNSolves(), SCIPnlpiGetSolveTime(), SCIPnlpiGetEvalTime(), SCIPnlpiGetNIterations(), SCIPnlpiGetNTermStat(), SCIPnlpiGetNSolStat(), SCIPnlpiMergeStatistics()
1382- added SCIPmergeNLPIStatistics(), SCIPprintNLPIStatistics()
1383- added SCIPnlpiOracleResetEvalTime(), SCIPnlpiOracleGetEvalTime()
1384- added SCIPaddNlpiProblemNlRows()
1387- added SCIPincludeCutsel(), SCIPincludeCutselBasic(), SCIPsetCutselCopy(), SCIPsetCutselFree(), SCIPsetCutselInit(), SCIPsetCutselExit(), SCIPsetCutselInitsol(), SCIPsetCutselExitsol(), SCIPfindCutsel(), SCIPgetCutsels(), SCIPgetNCutsels(), SCIPsetCutselPriority()
1388- added SCIPcutselGetName(), SCIPcutselGetData(), SCIPcutselGetDesc(), SCIPcutselGetPriority(), SCIPcutselSetData(), SCIPcutselIsInitialized(), SCIPcutselGetSetupTime(), SCIPcutselGetTime()
1390### Command line interface
1391### Interfaces to external software
1393- removed GAMS interface (originally in interfaces/gams) and reading capability of gms reader;
1394 the removed interface was a poorly maintained copy of the GAMS/SCIP interface that is available at
1395 https://github.com/coin-or/GAMSlinks
1396- integrated AMPL interface into main SCIP executable, that is, added possibility to use SCIP executable as solver in AMPL
1397 (AMPL calls solver with name of .nl file and -AMPL as arguments; SCIP will then attempt to solve the problem and write an AMPL solution file)
1398- the ZIMPL interface has been updated to support ZIMPL 3.4.1;
1399 the minimal required ZIMPL version is now 3.4.1
1401### Changed parameters
1403- Extended range of parameter "misc/usesymmetry" from [0,3] to [0,7], changed default from 3 to 5
1404- deleted parameter "constraints/orbitope/usedynamicprop"
1405- changed type of parameter "propagating/symmetry/recomputerestart" from SCIP_Bool to int with range [0,2]
1406- deleted parameter "propagating/symmetry/disableofrestart"
1407- parameter "heuristics/padm/original" is now an advanced parameter
1408- removed constraints/nonlinear/linfeasshift, constraints/nonlinear/reformulate, constraints/nonlinear/maxexpansionexponent, constraints/nonlinear/sepanlpmincont
1409- removed constraints/nonlinear/upgrade/abspower
1410- removed constraints/nonlinear/upgrade/and, use constraints/nonlinear/reformbinprodsand instead
1411- removed constraints/nonlinear/upgrade/bivariate
1412- removed constraints/nonlinear/upgrade/quadratic, use nlhdlr/quadratic/enabled instead
1413- changed default of constraints/nonlinear/maxproprounds from 1 to 10
1414- replaced constraints/nonlinear/enfocutsremovable by constraints/nonlinear/rownotremovable
1415- replaced constraints/nonlinear/cutmaxrange by separating/maxcoefratiofacrowprep
1416- removed constraints/quadratic/sepafreq, constraints/quadratic/propfreq, constraints/quadratic/proptiming, constraints/quadratic/eagerfreq, constraints/quadratic/maxprerounds, constraints/quadratic/delaysepa, constraints/quadratic/delayprop, constraints/quadratic/presoltiming
1417- removed constraints/quadratic/replacebinaryprod, use constraints/nonlinear/reformbinprodsfac instead
1418- removed constraints/quadratic/empathy4and, use constraints/nonlinear/reformbinprodsand instead
1419- removed constraints/quadratic/binreforminitial, constraints/quadratic/binreformbinaryonly, constraints/quadratic/binreformmaxcoef
1420- removed constraints/quadratic/cutmaxrange, constraints/quadratic/mincurvcollectbilinterms, constraints/quadratic/linearizeheursol, constraints/quadratic/checkcurvature, constraints/quadratic/checkfactorable, constraints/quadratic/checkquadvarlocks, constraints/quadratic/linfeasshift
1421- removed constraints/quadratic/maxdisaggrsize, constraints/quadratic/disaggrmergemethod, constraints/quadratic/maxproprounds, constraints/quadratic/maxproproundspresolve, constraints/quadratic/enfolplimit, constraints/quadratic/sepanlpmincont, constraints/quadratic/enfocutsremovable
1422- removed constraints/quadratic/gaugecuts, constraints/quadratic/interiorcomputation, constraints/quadratic/projectedcuts, constraints/quadratic/branchscoring, constraints/quadratic/usebilinineqbranch, constraints/quadratic/bilinineqmaxseparounds,
1423- removed constraints/quadratic/minscorebilinterms, use nlhdlr/bilinear/enabled instead
1424- removed constraints/quadratic/upgrade/linear, constraints/quadratic/upgrade/abspower, constraints/quadratic/upgrade/bivariate, constraints/quadratic/upgrade/bounddisjunction
1425- removed constraints/quadratic/upgrade/soc, use nlhdlr/soc/enabled instead
1426- renamed constraints/quadratic/upgrade/setppc to constraints/nonlinear/upgrade/setppc
1427- removed constraints/abspower/sepafreq, constraints/abspower/propfreq, constraints/abspower/proptiming, constraints/abspower/eagerfreq, constraints/abspower/maxprerounds, constraints/abspower/delaysepa, constraints/abspower/delayprop, constraints/abspower/presoltiming
1428- removed constraints/abspower/cutmaxrange, constraints/abspower/projectrefpoint, constraints/abspower/preferzerobranch, constraints/abspower/branchminconverror, constraints/abspower/addvarboundcons, constraints/abspower/linfeasshift, constraints/abspower/dualpresolve, constraints/abspower/sepainboundsonly, constraints/abspower/sepanlpmincont, constraints/abspower/enfocutsremovable
1429- removed constraints/bivariate/sepafreq, constraints/bivariate/propfreq, constraints/bivariate/proptiming, constraints/bivariate/eagerfreq, constraints/bivariate/maxprerounds, constraints/bivariate/delaysepa, constraints/bivariate/delayprop, constraints/bivariate/presoltiming
1430- removed constraints/bivariate/cutmaxrange, constraints/bivariate/linfeasshift, constraints/bivariate/maxproprounds, constraints/bivariate/ninitlprefpoints, constraints/bivariate/enfocutsremovable
1431- removed constraints/soc/sepafreq, constraints/soc/propfreq, constraints/soc/proptiming, constraints/soc/eagerfreq, constraints/soc/maxprerounds, constraints/soc/delaysepa, constraints/soc/delayprop, constraints/soc/presoltiming
1432- removed constraints/soc/projectpoint, constraints/soc/nauxvars, constraints/soc/glineur, constraints/soc/sparsify, constraints/soc/sparsifymaxloss, constraints/soc/sparsifynzgrowth, constraints/soc/linfeasshift, constraints/soc/nlpform, constraints/soc/sepanlpmincont, constraints/soc/enfocutsremovable, constraints/soc/disaggregate
1433- removed constraints/soc/generalsocupgrade, use nlhdlr/soc/compeigenvalues instead
1434- changed default of presolving/qpkktref/maxrounds from -1 to 0
1435- changed default of propagating/obbt/onlynonconvexvars from FALSE to TRUE
1436- changed default of heuristics/subnlp/resolvetolfactor from 0.001 to 1.0
1437- removed heuristics/subnlp/nlpoptfile, use nlpi/ipopt/optfile instead
1438- removed separating/convexproj/nlptimelimit
1439- removed separating/gauge/nlptimelimit
1440- removed heuristics/subnlp/nlptimelimit and heuristics/subnlp/nlpiterlimit
1441- removed heuristics/subnlp/resolvetolfactor and heuristics/subnlp/resolvefromscratch
1442- changed default of heuristics/subnlp/itermin to 20
1443- renamed heuristics/subnlp/iteroffset to heuristics/subnlp/nodesoffset
1444- renamed heuristics/subnlp/iterquotient to heuristics/subnlp/nodesfactor
1445- removed heuristics/subnlp/runalways, use heuristics/subnlp/nodesoffset=INT_MAX and heuristics/subnlp/successrateexp = 0.0 instead
1446- removed heuristics/subnlp/minimprove, heuristics/multistart/nlpminimpr
1447- Removed parameters for strongcg separator: separating/strongcg/..., i.e.,
1448 maxrounds, maxroundsroot, maxsepacutsroot, maxsepacuts, dynamiccuts. One can control the
1449 strongcg behavior throught the parameters of sepa_gomory.
1450- renamed separating/{minortho,minorthoroot,objparalfac,intsupportfac} to cutselection/hybrid/{minortho,minorthoroot,objparalweight,intsupportweight}
1454- It is now possible to add orbitope constraints to handle symmetries even if not all variables
1455 in a component of the symmetry group are binary. This feature can be enabled using the
1456 parameter "propagating/symmetry/onlybinorbitope".
1458- new parameter "propagating/symmetry/sstleaderrule" to select a rule for selecting the
1460- new parameter "propagating/symmetry/ssttiebreakrule" to select a tiebreak rule for selecting the
1462- new parameter "propagating/symmetry/sstleadervartype" to select the possible variable types
1463 for a leader in SST cuts
1464- new parameter "propagating/symmetry/addconflictcuts" to control whether SST cuts are added if
1465 a binary leader variable is in conflict with a variable in its orbit
1466- new parameter "propagating/symmetry/sstaddcuts" to control whether SST cuts are added
1467- new parameter "propagating/symmetry/sstmixedcomponents" to control whether SST cuts are added
1468 if a symmetry component contains variables of different types
1469- new parameter "propagating/symmetry/detectsubgroups" to search for orbitopes defined by subgroups
1470- new parameter "propagating/symmetry/addweaksbcs" to add Schreier Sims cuts for a single
1471 variable orbit in case an orbitope subgroup is detected
1472- new parameter "propagating/symmetry/addstrongsbcs" to add symretope facets for a single
1473 variable orbit on which the symmetry group acts like a symmetric group
1474- new parameter "propagating/symmetry/maxnconsssubgroup" to control up to which number of
1475 constraints subgroups are detected
1476- new parameter "propagating/symmetry/preferlessrows" to control whether orbitopes with
1477 smallest number of rows shall be computed by the subgroup detection heuristic
1478- new parameter "propagating/symmetry/usedynamicprop" to control if rows of full orbitope
1479 shall be ordered dynamically in propagation
1480- new parameter "separating/filtercutpoolrel" to control whether cutpool uses
1481 a dynamic strategy to separate only cuts with high relative efficacy
1482- if run from AMPL: display/statistics to enable printing detailed solve statistics after solve
1483- if run from AMPL: display/logfile to specify name of file to write SCIP log to (additionally to writing to stdout)
1484- constraints/nonlinear/propauxvars, constraints/nonlinear/varboundrelax, constraints/nonlinear/varboundrelaxamount, constraints/nonlinear/conssiderelaxamount
1485- constraints/nonlinear/vpmaxperturb, constraints/nonlinear/vpadjfacetthresh, constraints/nonlinear/vpdualsimplex
1486- constraints/nonlinear/bilinmaxnauxexprs, constraints/nonlinear/forbidmultaggrnlvar, constraints/nonlinear/checkvarlocks, constraints/nonlinear/violscale
1487- constraints/nonlinear/reformbinprods, constraints/nonlinear/reformbinprodsand, constraints/nonlinear/reformbinprodsfac
1488- constraints/nonlinear/tightenlpfeastol, constraints/nonlinear/propinenforce, constraints/nonlinear/weakcutthreshold, constraints/nonlinear/strongcutmaxcoef, constraints/nonlinear/strongcutefficacy, constraints/nonlinear/forcestrongcut, constraints/nonlinear/enfoauxviolfactor, constraints/nonlinear/weakcutminviolfactor
1489- constraints/nonlinear/branching/aux, constraints/nonlinear/branching/external, constraints/nonlinear/branching/highviolfactor, constraints/nonlinear/branching/highscorefactor, constraints/nonlinear/branching/violweight, constraints/nonlinear/branching/dualweight, constraints/nonlinear/branching/pscostweight, constraints/nonlinear/branching/domainweight, constraints/nonlinear/branching/vartypeweight, constraints/nonlinear/branching/scoreagg, constraints/nonlinear/branching/violsplit, constraints/nonlinear/branching/pscostreliable
1490- constraints/nonlinear/linearizeheursol
1491- nlhdlr/default/enabled
1492- nlhdlr/convex/enabled, nlhdlr/convex/detectsum, nlhdlr/convex/extendedform, nlhdlr/convex/cvxquadratic, nlhdlr/convex/cvxsignomial, nlhdlr/convex/cvxprodcomp, nlhdlr/convex/handletrivial
1493- nlhdlr/concave/enabled, nlhdlr/concave/detectsum, nlhdlr/concave/cvxquadratic, nlhdlr/concave/cvxsignomial, nlhdlr/concave/cvxprodcomp, nlhdlr/concave/handletrivial
1494- nlhdlr/bilinear/enabled, nlhdlr/bilinear/useinteval, nlhdlr/bilinear/usereverseprop, nlhdlr/bilinear/maxseparoundsroot, nlhdlr/bilinear/maxseparounds, nlhdlr/bilinear/maxsepadepth
1495- nlhdlr/perspective/enabled, nlhdlr/perspective/maxproprounds, nlhdlr/perspective/mindomreduction, nlhdlr/perspective/minviolprobing, nlhdlr/perspective/probingonlyinsepa, nlhdlr/perspective/probingfreq, nlhdlr/perspective/convexonly, nlhdlr/perspective/tightenbounds, nlhdlr/perspective/adjrefpoint
1496- nlhdlr/quadratic/enabled, nlhdlr/quadratic/useintersectioncuts, nlhdlr/quadratic/usestrengthening, nlhdlr/quadratic/useboundsasrays, nlhdlr/quadratic/ncutslimit, nlhdlr/quadratic/ncutslimitroot, nlhdlr/quadratic/maxrank, nlhdlr/quadratic/mincutviolation, nlhdlr/quadratic/minviolation, nlhdlr/quadratic/atwhichnodes, nlhdlr/quadratic/nstrengthlimit, nlhdlr/quadratic/ignorebadrayrestriction, nlhdlr/quadratic/ignorehighre
1497- nlhdlr/quotient/enabled
1498- nlhdlr/soc/enabled, nlhdlr/soc/mincutefficacy, nlhdlr/soc/compeigenvalues
1499- propagating/obbt/createlincons
1500- propagating/symmetry/onlybinarysymmetry
1501- separating/minor/priority, separating/minor/freq, separating/minor/maxbounddist, separating/minor/delay, separating/minor/expbackoff, separating/minor/maxminorsconst, separating/minor/maxminorsfac, separating/minor/mincutviol, separating/minor/maxrounds, separating/minor/maxroundsroot, separating/minor/ignorepackingconss
1502- separating/rlt/priority, separating/rlt/freq, separating/rlt/maxbounddist, separating/rlt/delay, separating/rlt/expbackoff, separating/rlt/maxncuts, separating/rlt/maxunknownterms, separating/rlt/maxusedvars, separating/rlt/maxrounds, separating/rlt/maxroundsroot, separating/rlt/onlyeqrows, separating/rlt/onlycontrows, separating/rlt/onlyoriginal, separating/rlt/useinsubscip, separating/rlt/useprojection, separating/rlt/detecthidden, separating/rlt/hiddenrlt, separating/rlt/addtopool, separating/rlt/goodscore, separating/rlt/badscore, separating/rlt/objparalweight, separating/rlt/efficacyweight, separating/rlt/dircutoffdistweight, separating/rlt/goodmaxparall, separating/rlt/maxparall
1503- separating/interminor/usestrengthening, separating/interminor/usebounds, separating/interminor/mincutviol, separating/interminor/maxrounds, separating/interminor/maxroundsroot
1504- table/cons_nonlinear/active, table/nlhdlr/active, table/exprhdlr/active, table/nlpi/active, table/nlhdlr_bilinear/active, table/nlhdlr_quadratic/active
1505- expr/log/minzerodistance, expr/pow/minzerodistance
1506- benders/default/maxslackvarcoef to specify maximal coefficient for slack variables; if exceeded, slack variables are fixed to zero
1507- nlpi/ipopt/optfile to specify name of Ipopt options file to use for every solve with Ipopt
1508- nlpi/ipopt/print_level, nlpi/ipopt/hsllib, nlpi/ipopt/pardisolib, nlpi/ipopt/linear_solver, nlpi/ipopt/linear_system_scaling, nlpi/ipopt/nlp_scaling_method, nlpi/ipopt/mu_strategy, nlpi/ipopt/hessian_approximation
1509- nlpi/ipopt/warm_start_push
1511- heuristics/subnlp/iterinit, heuristics/subnlp/ninitsolves, heuristics/subnlp/successrateexp
1512- heuristics/subnlp/expectinfeas, heuristics/subnlp/opttol, heuristics/subnlp/feastolfactor
1513- heuristics/subnlp/presolveemphasis, heuristics/subnlp/setcutoff
1514- new parameters "branching/inference/conflictprio" and "branching/inference/cutoffprio" that allow
1515 using the different score criteria in inference branching hierarchically
1516- new parameters "heuristics/alns/nodesquotmin", "heuristics/alns/maxcallssamesol" and "heuristics/alns/initduringroot"
1517 to control neighborhoods in ALNS
1518- new parameter "benders/default/benderscut/optimality/mir" to control whether mixed-integer rounding procedure is applied to Benders optimality cuts
1519- new parameter "misc/avoidmemout" to try to avoid running into memory limit
1520- cutselection/hybrid/dircutoffdistweight, cutselection/hybrid/efficacyweight, cutselection/hybrid/intsupportweight, cutselection/hybrid/objparalweight, cutselection/hybrid/priority
1521- new parameter "decomposition/disablemeasures" to disable expensive measures in SCIPcomputeDecompStats()
1522- new parameter "presolving/milp/probfilename" filename to write the problem to a file before MILP presolving starts
1526- removed quadratic terms from NLROWs
1527- removed SCIP_NLPPAR_INFINITY from SCIP_NLPPARAM enum
1528- added types SYM_OPTYPE, SYM_CONSTTYPE, SYM_RHSTYPE, SYM_EXPRDATA
1529- removed class SCIPInterval
1530- removed enum SCIP_EXPROP
1531- removed union SCIP_EXPROPDATA, added SCIP_EXPRDATA
1532- removed struct SCIP_EXPRTREE, use SCIP_EXPR instead
1533- removed structs SCIP_QUADELEM, SCIP_EXPRDATA_QUADRATIC, SCIP_EXPRDATA_MONOMIAL, SCIP_EXPRDATA_POLYNOMIAL, SCIP_EXPRDATA_USER
1534- removed structs SCIP_EXPRGRAPHNODE, SCIP_EXPRGRAPH
1535- removed type SCIP_EXPRBOUNDSTATUS
1536- removed struct SCIP_USEREXPRDATA
1537- added enum SCIP_MONOTONE
1538- added structs SCIP_EXPRHDLR, SCIP_EXPRHDLRDATA
1539- added union SCIP_EXPRITER_USERDATA
1540- added enum SCIP_EXPRITER_TYPE
1541- added structs SCIP_EXPRITERDATA, SCIP_EXPRITER
1542- added type SCIP_EXPRPRINT_WHAT, struct SCIP_EXPRPRINTDATA
1543- removed enum SCIP_BIVAR_CONVEXITY
1544- removed structs SCIP_QUADVAREVENTDATA, SCIP_QUADVARTERM, SCIP_BILINTERM
1545- added structs SCIP_CONSNONLINEAR_AUXEXPR, SCIP_CONSNONLINEAR_BILINTERM
1546- added type SCIP_NLHDLR_METHOD
1547- added structs SCIP_NLHDLR, SCIP_NLHDLRDATA, SCIP_NLHDLREXPRDATA
1548- enum SCIP_NLPPARAM has been changed to a struct that holds values of parameters for an NLP solve
1549- removed SCIP_NLPPAR_OPTFILE/optfile from SCIP_NLPPARAM
1550- added SCIP_NLPTERMSTAT_INTERRUPT to SCIP_NLPTERMSTAT enum; returned from NLP solver if SCIPinterruptSolve() has been called
1551- renamed SCIP_NLPTERMSTAT_TILIM to SCIP_NLPTERMSTAT_TIMELIMIT
1552- renamed SCIP_NLPTERMSTAT_ITLIM to SCIP_NLPTERMSTAT_ITERLIMIT
1553- renamed SCIP_NLPTERMSTAT_LOBJLIM to SCIP_NLPTERMSTAT_LOBJLIMIT
1554- renamed SCIP_NLPTERMSTAT_NUMERR to SCIP_NLPTERMSTAT_NUMERICERROR
1555- renamed SCIP_NLPTERMSTAT_EVALERR to SCIP_NLPTERMSTAT_EVALERROR
1556- renamed SCIP_NLPTERMSTAT_MEMERR to SCIP_NLPTERMSTAT_OUTOFMEMORY
1557- renamed SCIP_NLPTERMSTAT_LICERR to SCIP_NLPTERMSTAT_LICENSEERROR
1558- added evaltime to SCIP_NLPSTATISTICS
1559- added structs SCIP_CUTSEL, SCIP_CUTSELDATA
1564- interfaces/gams/∗
1565- interfaces/ampl/∗
1567- src/scip/cons_bivariate.{c,h}
1568- src/scip/pub_misc_nonlinear.h
1569- src/scip/misc_nonlinear.c
1570- src/scip/scip_nonlinear.{c,h}
1571- src/scip/sepa_strongcg.{h|c}
1576- added cons/linear/nonlinupgd.c
1577- added cons/nonlinear/addcons.c
1578- added cons/nonlinear/bilinhash.c
1579- added cons/nonlinear/check.c
1580- added cons/nonlinear/copy.c
1581- added cons/nonlinear/create_nlrow.c
1582- added cons/nonlinear/curvature.c
1583- added cons/nonlinear/glbconss.c
1584- added cons/nonlinear/hessian.c
1585- added cons/nonlinear/locks.c
1586- added cons/nonlinear/nlhdlr.c
1587- added cons/nonlinear/nlhdlr_bilinear.c
1588- added cons/nonlinear/nlhdlr_concave.c
1589- added cons/nonlinear/nlhdlr_convex.c
1590- added cons/nonlinear/nlhdlr_perspective.c
1591- added cons/nonlinear/nlhdlr_quadratic.c
1592- added cons/nonlinear/nlhdlr_quotient.c
1593- added cons/nonlinear/nlhdlr_soc.c
1594- added cons/nonlinear/parse.c
1595- added cons/nonlinear/presolve.c
1596- added cons/nonlinear/propagate.c
1597- added cons/nonlinear/readers.c
1598- added cons/nonlinear/reformbinprods.c
1599- added cons/nonlinear/repair.c
1600- added cons/nonlinear/transform.c
1601- added cons/nonlinear/vertexpolyhedral.c
1602- removed cons/nonlinear/getCoeffsAndConstantFromLinearExpr.c
1603- removed cons/soc/upgrade.c
1604- added expr/abs/estimation.c
1605- added expr/commonsubexprs.c
1606- added expr/compare.c
1608- added expr/cos/cos.c
1609- added expr/cos/estimation.c
1610- added expr/curvature.c
1611- added expr/derivative.c
1612- added expr/entropy/entropy.c
1613- added expr/entropy/estimation.c
1615- added expr/exp/estimation.c
1617- added expr/getvarexprs.c
1619- added expr/hessian.c
1620- added expr/integrality.c
1621- added expr/iterator.c
1622- added expr/log/estimation.c
1623- added expr/monotonicity.c
1625- added expr/pow/estimation.c
1626- added expr/pow/pow.c
1627- added expr/product/estimation.c
1629- added expr/simplify.c
1630- added expr/sin/estimation.c
1631- added expr/sin/sin.c
1632- added expr/sum/estimation.c
1633- added nlpi/exprinterpret.c
1634- speedup test nlpi:solveQP in nlpi/nlpi.c
1635- added test projection:transitivity in prob/obbt.c
1637- added test intervalarith:sincos in scip/intervalarith.c
1639- added sepa/rlt/cuts.c
1640- added sepa/rlt/product_detection.c
1641- added sepa/rlt/separation.c
1642- added tests test_compute_symmetry:expr{1,2,3,4} in symmetry/compute.c
1647- the separate NLPI library has been integrated into the main SCIP library;
1648 uses of NLPILIBFILE or NLPILIBSRC in Makefiles that use make/make.project
1653- replace flag PARASCIP by THREADSAFE
1654- option AMPL is now ON by default
1655- add -D_XOPEN_SOURCE=600 cflag for compilation on systems other than windows
1656- add compile options directly instead of modifying CMAKE_C_FLAGS and CMAKE_CXX_FLAGS
1660- prefix PKG_CONFIG_PATH with Ipopt's pkgconfig dir instead of postfixing
1661- replace flag PARASCIP by THREADSAFE
1662- flag AMPL is now true by default
1663- libscip has been renamed to libscipbase and libscipsolver has been renamed to libscip
1664 in order to have the same library names for makefiles and cmake. For downward
1665 compatibility libscipsolver still exists (as a link).
1670- fixed handling of multi-aggregation in cons_symresack and cons_orbisack
1671- SCIPgetLowerbound() now consistently returns infinity when status is infeasible
1672- improved the likelihood that a solution that satisfies the nonlinear constraints in the transformed (presolved) problem is also feasible for the original problem
1673- worked around a problem with derivatives of pow at 0 with non-integer exponents in CppAD
1674- fixed that setting of feasiblity and optimiality tolerance for NLP relaxation was overwritten with defaults when solving NLP
1675- fixed variance computation in t-value computation in hypothesis testing of reliability branching
1676- fixed potential overflow in cuts.c:evaluateLiftingFunctionKnapsack()
1677- do not transfer dual reductions to main SCIP in sepa_rapidlearning if strong dual reductions are forbidden
1678- fixed a bug in cons_setppc.c:removeDoubleAndSingletonsAndPerformDualpresolve() which led to wrong variable aggregations
1679- added missing redundancy check to coefficient tightening routine in cons_varbound that led to wrong variable locks
1680- added a check of numerics to avoid wrong reductions in cons_linear.c:simplifyInequalities()
1681- fixed a bug in cons_logicor.c regarding fixed variables that were not removed
1682- presol_milp.c handles variable fixings, suggested by PaPILO, more carefully to cover all cases that can appear
1683- fixed several reproducability bugs that led to different solving paths across multiple runs with one SCIP environment
1684- fixed check of limits/absgap, which was incorrectly applied to the scaled objective of the transformed problem
1689- in LP, use absolute instead of relative tolerances to check whether solutions from LP solver are primal feasible
1690- when a restart occurs, SCIP now asserts (during EXITSOLVE) that all relaxation-only variables are unlocked and
1691 only captured by the transformed problem.
1692- Avoid redundant calls to LP solver when LP is already flushed and solved
1693- In SCIPdebugMsg(), SCIPsetDebugMsg(), SCIPstatDebugMsg() strip directory from filename.
1694- Recompute activity of rows when checking LP solutions instead of trusting the value given by the LP solver
1695- The define NPARASCIP has been replaced by SCIP_THREADSAFE
1696- Parameters are not reset to their default values before activating an emphasis setting; this now allows to combine
1697 different emphasis settings.
1698- If a lazy bound is set to a value that is tighter than the current global bound, then the global bound is now tightened accordingly.
1700@page RN7 Release notes for SCIP 7
1702@section RN703 SCIP 7.0.3
1703*************************
1708### New API functions
1710- added function SCIPwithDebugSol() to determine whether SCIP was compiled with WITH_DEBUG_SOLUTION
1712- New function SCIPcreateConsBounddisjunctionRedundant() and SCIPcreateConsBasicBounddisjunctionRedundant() that allow
1713 the input to contain redundant literals.
1715### Changed API functions
1717- added __attribute__((format(printf,,,))) to variadic SCIP message printing functions;
1718 this enables warnings about mismatches between format string and variadic function arguments if using GCC.
1720### Interfaces to external software
1722- removed MATLAB interface from interfaces/matlab
1727- Compilation will now also work in a raw tarball of the scip git repository
1731- Make find_package more verbose and require packages to be found. Now enabled packages that are not found result in an error.
1736- Fixed numerical bug by creating and checking the empty solution when problem vanishes in presolving.
1737- Fixed several bugs in reoptimization.
1738- Fixed bug in cons_bounddisjunction in which a constraint leads to a cutoff.
1739- Fixed bug in reoptimization by avoiding redundant literals for bound disjunctions.
1740- Replace wrong usage of CMAKE_BINARY_DIR by PROJECT_BINARY_DIR in CMake system
1741- Fixed lpi_glop to use absl flag instead of GFlags
1742- Fixed invalid initialization of limits/softtime parameter in cons_components
1743- Fixed MIN macro not defined in some cases.
1744- Safeguard some API methods for querying solving statistics against segmentation faults after SCIPpresolve()
1745- Fixed unfreed solution in concurrent solving
1746- Make sure that logicor constraints are enforced/separated if genlogicor is true in cons_indicator.
1747 Thus, do not change constraints/logicor/sepafreq anymore, but output warning.
1748- Fixed assert that assumed infeasibility cannot occur in presol_boundshift.
1749- Fixed sign bug during creation of conflict constraints with almost zero left-hand side.
1750- Disabled call of conflict handler for conflict sets that contain relaxation-only variables.
1751- Fixed bug in cons_symresack by initializing all constraint data in constrans
1752- Avoid allowing the upgrade of linear constraints corresponding to indicators in propagation of nodes.
1753- Fixed bug in computing lex. min/max faces in dynamic orbitope propagation.
1754- Limit vbounds propagator to one sweep through all bounds per call in order to avoid an infinite loop.
1755- Fixed mismatches between formatter strings and arguments in calls to SCIP message printing functions.
1760- To avoid performance variablity during reoptimization, the active constraints are now stored in the same order as in the
1762- Added workaround for bug in MSVS 2019 when compiling CppAD source.
1763- The original order of variables is now only restored after presolve if `randomization/permutevars` is set to FALSE.
1765@section RN702 SCIP 7.0.2
1766*************************
1771- Extended check for valid variable and constraint names in PIP writer.
1772- Indicator constraints now write the name of the linear constraint in CIP format. This avoids a complicated
1773 name matching during parsing. The old format is still supported.
1774- The objective scale and offset are now taken into account when reading/writing problems in lp/mps/fzn/pip format.
1775 This often changes the behavior when writing transformed problems.
1777Performance improvements
1778------------------------
1780Examples and applications
1781-------------------------
1783- Add c++ Sudoku example
1788### Deleted and changed API methods
1790- deprecated SCIPsetParam(); use SCIPsetIntParam(), SCIPsetRealParam(), etc, instead
1792### New API functions
1794- new function SCIPcolGetVarProbindex() for accessing the probindex of a variable corresponding to a column
1795- added new sorting functions SCIPsortPtrRealRealBoolBool()
1800- Fixed a sign bug occuring for some cases in the computation of the directed cutoff distance
1801- Fixed overflow in inference information of cumulative constraint handler
1802- Fixed problem with propfreq == 0 in cons_linear.c
1803- Fixed aggregation heuristic in sepa_aggregation.c to not use local rows when that is requested nor modifiable rows
1804- Fixed problem with incompatibility of symmetry handling in Benders decomposition
1805- Fixed parsing of small number in CIP format of nonlinear constraint
1806- Fixed problem in upgrading full orbitopes to partitioning orbitopes
1807- Fixed treatment of negated variables in parsing orbitope constraints
1808- Fixed potential indexing error in prop_vbounds.c
1809- Fixed bug in writing fzn format
1810- Revert to old parameter value when parameter change is rejected in PARAMCHGD callback
1811- Fixed order of linker flags when building AMPL interface with cmake system.
1812- Fixed bug with ofsymcomptiming == 0: now symmetry is actually computed
1813- Improved separation for SOC constraint with multiaggregated variable on right-hand-side.
1814- Fixed bug in presol_boundshift: do not shift non-active variables
1815- Fixed bug in domain propagation for SOC constraints with negative coefficient for variable on right-hand-side.
1816- Fixed bug with multi-aggregated integer variables in cons_xor.
1817- Fixed bug with changed number of variables in storing relaxation solution in probing/diving.
1818- Fixed issues with scip statistics
1819- Fixed issue with multi-aggregated variables
1820- Fixed issue in with buffer memory in cons_cumulative
1822@section RN701 SCIP 7.0.1
1823*************************
1830- Fixed cmake module for Ipopt to support Ipopt 3.13
1831- Added cmake variable BLISS_LIBRARY_DIR to pass a bliss library
1832- Added warning to require minimal GCC version 4.8
1833- Renamed FindCriterion cmake findmodule to FindCRITERION
1837- Updated make/make.project for macOS
1838- Add SANITZERFLAGS (only OPT=dbg) to LDFLAGS also if SHARED=true (and rename SANITZERFLAGS to SANITIZERFLAGS)
1839- Fixed GCC version check in make/make.linux.gnu.dbg
1844- Fixed handling of constant term in quadratic objective of pip-reader
1845- Fixed incorrect value string for parameter estimation/completiontype
1846- Fixed initialization of first LP which led to wrong output about LPs not resolved correctly
1847- Fixed bug in SCIPcutpoolClear() function not clearing internal datastructures properly
1848- Fixed inability to set a value in a solution if it was within epsilon to the current value
1849- Fixed problems for linking optimized code with debug library of SCIP (and vice versa) by moving debug-only members
1850 to end of SCIP structs
1855- Variables that are marked as relaxation-only are no longer checked against debug solutions if
1856 they are captured by the transformed problem only.
1858@section RN700 SCIP 7.0.0
1859*************************
1864- Using the parameter "propagating/symmetry/recomputerestart" one can now decide to recompute symmetries after a
1865 restart or not. Previously one could just turn off symmetry computation after a restart. If orbital fixing
1866 has found a reduction before the restart occured, symmetries have to be updated to ensure correctness.
1867 To this end, the user can decide via "propagating/symmetry/disableofrestart" whether orbital fixing is disabled or
1868 whether symmetries are recomputed.
1870- extended relaxators statistics in solve statistics about information on number of cutoffs, improved bounds, etc.
1872- extends SMPS file reader for the stochastic information, the sto files, to read a lower bound for the discrete
1873 scenarios. The lower bound is used when creating the auxiliary variables for Benders' decomposition.
1875- extended Benders framework to solve NLPs and generate optimality and feasibility cuts from their solution
1876 when the subproblem is convex nonlinear.
1878- extended Benders framework to create copies of Benders decompositions that can be used in a multithreading environment
1880- additional functionality has been added to enable the transfer of Benders' decomposition cuts between different SCIP
1881 instances, e.g., when used in UG
1883- LP rows (SCIP_ROW) can now store pointer to a constraint from which the row originates
1885- Trust region, a new LNS heuristic, has been added to SCIP as both a standalone primal heuristic heur_trustregion.c
1886 and as a neighborhood inside of Adaptive Large Neighborhood Search (heur_alns.c). This heuristic is designed to improve the
1887 heuristic performance of the Benders' decomposition algorithm. It builds upon the successful trust region approaches
1888 applied to Benders' decomposition.
1890- Modularity of symmetry handling has been increased. It is now possible to use orbitopes (i.e., polyhedral symmetry
1891 handling techniques) and orbital fixing on the same instance.
1893- cut strengthening enabled within the Benders' decomposition framework. This uses a mix of the Improved Magnanti-Wong
1894 method and Kelly's method. The cut strengthening is enabled by setting the paramemter
1895 "benders/<bendersname>/cutstrengthenenabled" to TRUE. The parameters "cutstrengthenmult", "noimprovelimit" and
1896 "corepointperturb" control the behavior of the cut strengthening method. Additionally, the parameter
1897 "cutstrengthenintpoint" allows the user to specify the solution that is used to initialize the core point. The options
1898 are the first LP solution, the first integer feasible solution, a relative interior point, a solution vector of all
1899 ones and a solution vector of all zeros. Also, the core point can be reinitialized after each update to the incumbent
1902- added option to adjust weights of different scores in relpscost (hybrid) branching rule based on degeneracy information
1903 and skip strong branching for very high degeneracy rates
1905- added new SCIP_DECOMP* object to store user decompositions. The user can specify one or several decompositions by assigning variable
1906 and/or constraint labels either through the API or by reading a file in DEC format (which is one of the formats that GCG writes).
1907 This format specifies constraint labels, variable labels are inferred from that. The decomposition is transformed after presolving.
1908- statistics regarding the number of blocks, the largest and smallest blocks, the border, and the constraint graph are printed for the original decomposition,
1909 and for each decomposition after presolving.
1910- the decomposition can be used as initial decomposition for the Benders functionality of SCIP.
1911- new subsection "How to provide a problem decomposition" in the SCIP documentation
1913- GINS heuristic can make use of a user-provided decomposition labels in two ways:
1914 1. by selecting a block of variables that maximizes the potential, and randomly selecting a start variable for the neighborhood and/or
1915 2. by selecting an interval of consecutive blocks as neighborhood, until fixing rate is reached. In this case, no variable is randomly selected.
1917- extend potential parameter of GINS to allow computation based on local LP solution, as well
1919- new primal heuristic Adaptive Diving, which registers all publicly available dive sets from other diving heuristics.
1920 At each call, it selects one of the available dive sets based on the user's score type choice (heuristics/adaptivediving/scoretype).
1921 During the solution process, the heuristics learns online which divesets reach the best score, and executes them more frequently.
1922 The statistic output for Diving heuristics has been extended to incorporate the statistics of each dive set within Adaptive diving.
1924- Added new penalty alternating direction method (PADM) primal heuristic that splits the problem into several sub-SCIPs
1925 according to a user-provided decomposition. The sub-SCIPs are solved on an alternating basis until a feasible solution of
1926 the original problem is found.
1928- Symmetry handling constraints (cons_orbisack, cons_orbitope, cons_symresack) now have an additional parameter to encode
1929 whether they are model constraints, i.e., define the problem, or whether they are only present to handle symmetries.
1931- The symmetry code has been completely restructured. The presolvers presol_symbreak and presol_symmetry as well as the propagator
1932 prop_orbitalfixing have been merged into the single propagator prop_symmetry to avoid storing the same information
1933 multiple times. This propagator is now responsible for adding symmetry handling constraints as well as activating orbital
1934 fixing. Moreover, the new file symmetry.c contains general functions for symmetry computations like orbit computations.
1936- Variables can now be marked as "relaxation-only". This flag should be used to introduce new variables that are required
1937 to define a relaxation, but that are not part of any checked constraints. Essentially, these variables should only be used
1938 in the current SCIP solve and disregarded after a restart or in SCIP copies. Hence, these variables are not copied by SCIPcopy and
1939 SCIPgetVarCopy, they are currently not used in conflict constraints, and cuts involving them are not upgraded to linear constraints.
1940 Relaxation-only variables cannot appear in the objective function.
1942- The OSiL reader now supports nonlinear expressions of type "signpower".
1944- Expressions of form abs(x)^p * x in a nonlinear constraint are now sometimes recognized and handled by abspower constraints.
1946- If polyhedral symmetry handling methods are used (cons_orbisack, cons_orbitope, cons_symresack), it is now possible to
1947 recompute symmetries if a restart occured.
1949- upgrade some more quadratic constraints to second-order cone constraints, that is,
1950 handle linear binary variables as if squared in simple upgrade and
1951 do not require bounds for variables that have a zero entry in the computed eigenvectors in the non-simple upgrade
1953- new variable event when changing the variable type
1955- It is no longer necessary to provide a SCIP pointer for the subproblem in SCIPaddBendersSubproblem if custom solving
1956 methods are defined. A NULL pointer can be supplied to SCIPaddBendersSubproblem. In this case, no internal Benders'
1957 cut generation methods can be used.
1959- Using the parameter "constraints/symresack/checkmonotonicity" one can now decide to upgrade to packing/partitioning
1960 symresacks even if the underlying permutation is not monotone.
1962- New branching rule `vanillafullstrong`, mostly for scientific purpose, with the following features:
1963 1) no cutoff or domain reduction: only branching;
1964 2) idempotent (optional): leave SCIP, as much as possible, in the same state before / after the strong branching calls
1965 - basically, do not update any statistic;
1966 3) donotbranch (optional): do no perform branching. So that the brancher can be called as an oracle only
1967 (on which variable would you branch ? But do not branch please);
1968 4) scoreall (optional): keep scoring variables, even if infeasibility is detected;
1969 5) collectscores (optional): store the candidate scores from the last call, which can then be retrieved by calling SCIPgetVanillafullstrongData();
1970 6) integralcands (optional): consider integral candidates for branching,
1971 i.e., get candidates from SCIPgetPseudoBranchCands() instead of SCIPgetLPBranchCands().
1973- If a reference value (misc/referencevalue) is given, the primal-reference and reference-dual integrals are calculated automatically and printed within the SCIP statistics.
1975- Locally valid cuts / rows are now considered for dual proof analysis when `conflict/uselocalrows` is set to TRUE.
1977- Linking variables in the linking constraint handler (cons_linking.{ch}) can now be integer or continuous. The coefficients of the binary variables are therefore now stored as SCIP_Real.
1979- To save memory, it is now possible to remove all variables from the internal symmetry data structures that are
1980 not affected by any symmetry.
1982- Allow to filter first variables from orbits and transfer pseudo cost information to variables in orbit
1984- Add integration of external MILP presolve library as a SCIP presolver plugin that runs on MILP problems
1986- Parallelisation can be used when applying Benders' decomposition. There are two different forms of parallelisation
1987 available. The first is applying Benders' decomposition within a parallel branch-and-bound. This is achieved through
1988 the integration with the UG framework. The second is the use of shared memory parallelisation for solving the Benders'
1989 decomposition subproblems. A priority queue has been added to help with load balancing.
1991- The Benders' decomposition framework can handle MINLPs. If a convex relaxation of the MINLP exists, then this is
1992 solved to generate optimality and feasibility cuts. The extensions to the framework are:
1993 - New generic solving methods to solve convex NLP subproblems.
1994 - Modification to benderscut_opt and benderscut_feas to enable the generation of cuts from convex NLPs.
1995 - Addition of benderscut_feasalt to generate feasibility cuts from an alternative subproblem that minimises the
1996 violation of infeasible problems.
1997 - Better handling of subproblem solution results
1999- Adds a feasibility phase to the Benders' decomposition subproblem solving methods. The feasibility phase adds slack
2000 variables to each of the constraints to ensure feasibility of the subproblem. A large coefficient is given to these
2001 slack variables in the objective function to penalise constraint violations. The coefficients are progressively
2002 increased until all slack variables take the value 0.0.
2004- Improved convexity check for Benders' decomposition subproblems. The constraints of the subproblem are now checked for
2005 convexity in the initialisation of the Benders' decomposition algorithm. This enables the solving of convex NLPs as
2006 Benders' decomposition subproblems.
2008- Benders' decomposition can be applied using decomposition supplied in the DEC format. To apply Benders' decomposition
2009 the parameters decomposition/benderslabels and decomposition/applybenders must be set to TRUE.
2011- new event handler event_estim.c/h that approximates search tree completion and estimates tree size
2012 to trigger restarts; many approximations of search tree completion and estimation, including WBE, SSG, and tree profile method
2013- new display column that reports approx. search tree completion during the search, and an overview in the statistics table
2014- added resources (script, tutorial, test data) to adapt tree size estimation to user instances.
2016- Orbital Fixing uses a list of variables that have been fixed globally since the computation of symmetries to filter
2017 symmetries. Previously, some plugins were disabled, which is not necessary anymore.
2019- A new presolver "dualsparsify" was added. It tries to combine columns (i.e. variables) to cancel nonzero coefficients in the constraint matrix.
2021- The presolver "tworowbnd" was implemented with better performance.
2023- To be able to calculate better bounds for the dual variables, the presolver "dualinfer" was extended by the ability to perform convex combinations of continuous columns.
2025- allow disabling of pricers during solving process
2027- added emphasis setting for numerically challenging instances
2029Performance improvements
2030------------------------
2032- Extended cut presolving by removing variables that been fixed at their bounds
2034- Improved branching point selection when branching on externals branching candidates. Instead of using exactly the
2035 LP solution, a point closer to the middle of the variables domain is chosen.
2037- Matrix presolvers that do not work on incomplete matrices now skip matrix creation if unsupported constraint types are detected.
2039- consLockBenders callback implemented to add down locks on the Benders' decomposition auxiliary variables and
2040 up and down locks per subproblem for all master problem variables. This allows the use of presolving and propagation
2041 with Benders' decomposition.
2043- improved performance of orbital fixing in several ways:
2044 store permutations in transposed form to improve cache efficency;
2045 reverse order to speed up filtering of permutations;
2046 handle variables globally fixed to 1 in list;
2047 use event handler to catch global fixings;
2048 speed up orbit computations;
2049 change handling of restarts;
2050 use only permutations that can contribute to a variable's orbit;
2052- allow rapid learning at local nodes
2054- allow to recompute cut without using fractional values for sepa_cgmip
2056- restrict the number of the clique table nonzeros relative to the number of problem nonzeros, which could be a performance bottleneck.
2058- variable fixings of LP face heuristic are now computed earlier; subproblem creation is skipped if not enough variables are fixed.
2060- Improved domcol presolver to not require a complete representation of all constraints in the matrix
2062- performance improvement of adaptive large neighborhood search heuristic on merely continuous problems. The heuristic
2063 stops if presolving in the sub-SCIP fixes less than 50 % of the current target fixing rate over all variables
2064 (including continuous).
2066- reduce memory usage in symmetry detection by a staggered allocation with decreasing overhead for larger instances
2068- improved full orbitope propagation using a static implementation or a dynamic reordering of orbitope rows by a global rank function
2070- improved detection of packing/partitioning orbitopes
2072- enable an in-tree restart if after a reasonable initialization, the estimated size of the remaining tree is large.
2075Examples and applications
2076-------------------------
2078- added methods to set and get hmin and hmax for optcumulative constraints
2083### New and changed callbacks
2085- new optional callback `SCIP_DECL_DIVESETAVAILABLE` to check preconditions for this dive set, e.g., if an incumbent solution is available,
2086 which is passed as new argument to SCIPcreateDiveset(). SCIPcreateDiveset() has another new parameter "ispublic".
2088- new callback `SCIP_DECL_CONSHDLRCOPY` and `SCIP_DECL_CONSCOPY` in cons_orbisack and cons_symresack
2090- new `idempotent` argument to SCIPgetVarStrongbranchInt() and SCIPgetVarStrongbranchFrac(),
2091 so that statistics are not updated during the call. Likewise, new `updatecol` and `updatestat` arguments to SCIPcolGetStrongbranch().
2093- callback `SCIP_DECL_CONSHDLRENFOLP` can now also return SCIP_SOLVELP as *result, which indicates to the SCIP core that the LP relaxation
2094 should be solved again because the primal feasibility tolerance of the LP has been tightened (using SCIPsetLPFeastol())
2096- extension of SCIP_PQUEUE by a new callback SCIP_DECL_PQUEUEELEMCHGPOS to catch swaps as well as functionality to delete arbitrary elements from the priority queue.
2098### Deleted and changed API methods
2101 + now for all lp interfaces consistent requirements on SCIP_LPPAR:
2102 LPITLIM and BARRIERCONVTOL positive or zero; FEASTOL, DUALFEASTOL, LPTILIM strictly positive
2103 + now projecting SCIP_LPPAR values on feasible values for each lp interface
2104 + add interface to Glop
2105 + fixed mapping between scaling parameter values in Gurobi LPI lpi_grb
2107 + removed method SCIPseparateCoversOrbisack() in cons_orbisack.h since the orbitope constraint
2108 handler has its own implementation of this routine with advanced features now
2109 + renamed SCIPgetGeneratorsSymmetry() to SCIPgetSymmetry() and removed two arguments
2110 + extended method SCIPgetSymmetry(): It is possible to access both the original and
2111 transposed permutations matrix as well as the (independent symmetry) components of a permutation group now.
2112 + arguments of functions SCIPcreateConsOrbisack(), SCIPcreateConsBasicOrbisack(), SCIPcreateConsOrbitope(),
2113 SCIPcreateConsBasicOrbitope(), SCIPcreateConsSymresack(), SCIPcreateConsBasicSymresack(), and SCIPcreateSymbreakCons() extended
2114 by "ismodelcons" to encode whether the constraints are model constraints or not
2115 + the function SCIPgetSymmetry() no longer accepts the parameter recompute, but has parameter permvarmap as new input
2116 + removed SCIPgetPermvarsObjSymmetry(), SCIPsetSymmetryComponentblocked(), SCIPgetSymmetryComponentblocked(),
2117 SCIPgetSyminfoGloballyFixedVars(), SCIPcomputeGroupOrbitsSymbreak, SCIPincludePresolSymmetry(),SCIPincludePresolSymbreak(),
2118 and SCIPincludePropOrbitalfixing()
2119 + add function SCIPcomputeOrbitsComponentsSym() to compute orbits without filtering permutations and indices of orbits for each variable
2120- SCIPallowObjProp() and SCIPallowDualReds() are deprecated and replaced by SCIPallowWeakDualReds() and SCIPallowStrongDualReds(), respectively
2121- Benders' decomposition
2122 + changed SCIPstoreBenderscutCut() in scip_benders.c to SCIPstoreBendersCut(). Where this function used to take a
2123 SCIP_BENDERSCUT pointer, it now accepts a SCIP_BENDERS pointer.
2124 + the functions SCIPsolveBendersSubproblem() no longer accepts the parameter type. The type is not a necessary
2125 argument for the subproblem solving method.
2126 + arguments of functions SCIPbendersSolveSubproblemLP(), SCIPbendersSolveSubproblemCIP(), and SCIPbendersOnlyCheckConvexRelax() changed
2127 - removed SCIPbenderscutGetNAddedCuts() and SCIPbenderscutGetAddedCutData()
2130### New API functions
2132- new argument "onlyifcomplete" in SCIPmatrixCreate() to skip matrix creation right after detecting unsupported constraint types
2133 and new arguments to count statistics when doing a clean-up of inactive variables in the constraints before building the matrix
2135- new argument "threadsafe" in SCIPcopy(), SCIPcopyConsCompression(), SCIPcopyOrig(), SCIPcopyOrigConsCompression and
2136 SCIPcopyBenders(). This argument must only be set to TRUE if the source and target SCIP instances are to be solved in
2137 parallel. Setting this argument to TRUE has a performance cost.
2139- new argument "append" in SCIPsetModifiedDefaultSettingsIpopt()
2140- functions SCIPclearRelaxSolVals(), SCIPsetRelaxSolVal(), SCIPsetRelaxSolVals(), SCIPsetRelaxSolValsSol(), and SCIPmarkRelaxSolValid()
2141 receive an additional argument "relax" to store the relaxation handler as creator of the relaxation solution.
2144 - SCIProwGetOriginCons() now returns a SCIP_CONS* instead of a SCIP_CONSHDLR*, use SCIProwGetOriginConshdlr() for the previous behavior
2145 - SCIPcreateRowCons() and SCIPcreateEmptyRowCons() now expect a SCIP_CONS* instead of a SCIP_CONSHDLR*,
2146 use SCIPcreateRowConshdlr() and SCIPcreateEmptyRowConshdlr(), respectively, for the previous behavior
2147 - deprecated SCIPlpfeastol() and SCIPchgLpfeastol(), use SCIPgetLPFeastol() and SCIPsetLPFeastol()
2149- new parameter "divecontext" for every method that queries statistics for a diveset. The context can be used to distinguish between the dive set
2150 as single (standalone) heuristic or within Adaptive Diving.
2151- new parameters "divecontext" and "iterlim" to SCIPperformGenericDivingAlgorithm() to control in which context (single,adaptive) statistics are updated.
2153- SCIPcopyVars, SCIPcopy, SCIPcopyConsCompression, and SCIPgetVarCopy do not copy variables that are marked as relaxation-only,
2154 thus it cannot be assumed anymore that each active variable from the master SCIP also has a counterpart in the copy.
2155 SCIPcopy, SCIPcopyConsCompression, and SCIPcopyConss can now return *valid=TRUE if some non-checked and non-enforced constraints were not copied, e.g.,
2156 because they involved relaxation-only variables. Thus, a copy is already regarded as valid if all checked or enforced constraints were copied successfully.
2158- linking constraint handler:
2159 - changed type of vals argument from int* to SCIP_Real* in SCIPcreateConsLinking() and SCIPcreateConsBasicLinking()
2160 - SCIPgetIntvarLinking() has been renamed to SCIPgetLinkvarLinking().
2161 - changed return value of SCIPgetValsLinking() from int* to SCIP_Real*.
2162 - new method SCIPgetBinvarsDataLinking().
2164- SCIPbendersCheckSubproblemOptimality() now returns a boolean indicating whether the subproblem is optimal or not.
2165 Previously this result was returned through a parameter. The change was required to facilitate the integration with
2168- deleted SCIPcombineTwoInt(), SCIPcombineThreeInt(), SCIPcombineFourInt(); use the appropriate SCIPhashTwo(), ..., SCIPhashSeven() method instead
2170- SCIPsetupBendersSubproblem takes a parameter of the enforcement type.
2172- SCIPcreateNlpiProb takes a hashmap to store the map between the nlrows and the index in the nlrow array.
2174### New API functions
2176- SCIPallowWeakDualReds() and SCIPallowStrongDualReds() replace the deprecated SCIPallowObjProp() and SCIPallowDualReds(), respectively
2177- methods have been added to facilitate the transfer of Benders' decomposition cuts between solvers in UG. These include
2178 SCIPapplyBendersStoredCuts(), SCIPbendersGetNStoredCuts(), SCIPbendersGetStoredCutData() and
2179 SCIPbendersGetStoredCutOrigData().
2180- added SCIPisConvexAbspower()
2181- new functions SCIPsolGetType(), SCIPsolGetRelax(), SCIPsolSetRelax(), SCIPsolSetLPRelaxation(), SCIPsolSetStrongbranch(),
2182 SCIPsolSetPseudo to set or query the new type attribute of a primal solution. The type attribute gives information
2183 about the origin of the solution, ie, whether it was created by a relaxation handler,
2184 by the LP relaxation, by strong branching, by the current pseudo solution, or by a primal heuristic.
2185 The meaning of the argument 'heur' in all creation methods for primal solutions such as SCIPcreateSol() stays unchanged.
2186- added SCIProwGetOriginConshdlr(), SCIPcreateRowConshdlr(), SCIPcreateEmptyRowConshdlr()
2187- new API functions SCIPsetCommonSubscipParams(), SCIPtranslateSubSol(), and SCIPtranslateSubSols() shared by several Large Neighborhood Search heuristics.
2188- new API function SCIPgetLPDualDegeneracy() to get two measures for the dual degeneracy of the current LP
2189- new API functions SCIPdivesetIsAvailable() to check preconditions of a dive set and SCIPdivesetIsPublic() to check if the dive set can be used
2190 by other primal heuristics.
2191- new API functions SCIPcomputeOrbitsSym(), SCIPcomputeOrbitsFilterSym(), SCIPgetPropertiesPerm(), SCIPdetermineBinvarAffectedSym(),
2192 SCIPdetermineNVarsAffectedSym(), SCIPcomputeComponentsSym(), and SCIPextendSubOrbitope(), SCIPgenerateOrbitopeVarsMatrix() for symmetry computations
2193- new API functions SCIPvarIsRelaxationOnly() and SCIPvarMarkRelaxationOnly() to query and set, resp., whether a variable is marked as relaxation-only
2194- new API functions SCIPconshdlrGetNUpdateConss() and SCIPconshdlrGetUpdateConss(), for expert users only
2195- new API function SCIPgetNConflictDualproofsApplied()
2196- new API functions SCIPeventGetOldtype() and SCIPeventGetNewtype() for the new event when changing the variable type
2197- new API function SCIPisConvexConsQuadratic() to check whether a quadratic constraint is convex when a given set of variables would be fixed
2198- new API functions SCIPgetLPFeastol(), SCIPsetLPFeastol(), and SCIPresetLPFeastol() to get, set, and reset (to the default), respectively, the primal
2199 feasibility tolerance for the LP relaxation
2200- new API functions SCIPcleanupConss{Linear,Varbound,Setppc,Logicor,Knapsack}() to clean up inactive variables from those types of linear constraints
2201- new API function SCIPsetBendersSubproblemComp() used to add a custom comparison method for ordering the Benders'
2202 decomposition subproblem solves. The comparison method is used to help with load balancing.
2203- new API function SCIPgetRowObjParallelism to get the objective parallelism of a row
2204- new API function SCIPcolGetAge to get the age of a column
2205- added SCIPhashThree(), SCIPhashFive(), SCIPhashSix(), and SCIPhashSeven() that complement SCIPhashTwo(), SCIPhashFour() to combine 32bit integers to
2207- new API function SCIPgenerateAndApplyBendersOptCut is used to generate a Benders' optimality cut using the dual
2208 solutions. This function can be supplied vectors for the primal and dual solution for generating an optimality cut.
2209 This avoids the need for a SCIP instance to solve the Benders' decomposition subproblem and generating cuts.
2210- new API function SCIPconsAddCoef used for adding a coefficient to a linear-type constraint.
2211- new API functions SCIPconsNonlinearGetRhs, SCIPconsNonlinearGetLhs and SCIPconsNonlinearAddLinearCoef for getting the
2212 RHS and LHS from a nonlinear-type constraint and adding a linear coefficient to the constraint.
2213- new API function SCIPbendersSolSlackVarsActive for checking whether any slack variables from the feasibility phase are
2214 active in the subproblem solution.
2215- new API functions SCIPbendersSetSubproblemType and SCIPbendersGetSubproblemType sets and gets the subproblem type.
2217 - Convex constraints with continuous variables
2218 - Convex constraints with discrete variables
2219 - Non-convex constraints with continuous variables
2220 - Non-convex constraints with discrete variables
2221- new API functions SCIPbendersSetSubproblemIsNonlinear() and SCIPbendersSubproblemIsNonlinear() for setting and
2222 identifying whether the Benders' decomposition subproblems contain nonlinear constraints. Similarly, the functions
2223 SCIPbendersSetMasterIsNonlinear() and SCIPbendersMasterIsNonlinear() sets and identifies whether the Benders'
2224 decomposition master problem contains nonlinear constraints.
2225- new API function SCIPapplyBendersDecomposition for applying Benders' decomposition given a decomposition in the DEC
2227- new API function SCIPwasNodeLastBranchParent to query if a node has been the parent of the most recent branching in the tree
2228- new API functions SCIPtreemodelInit(), SCIPtreemodelFree(), SCIPtreemodelIsEnabled(), SCIPtreemodelSelectCandidate() related to the new
2229 treemodel way of comparing branching candidates. These functions are only currently used for reliability pscost branching, but they can be used
2230 in other parts of the code.
2231- New function SCIPcalcChildEstimateIncrease() to compute the increase in the child estimation
2232- new API functions SCIPisOrbitalfixingEnabled() and SCIPgetSymmetryNGenerators() to check whether orbital fixing is
2233 enabled and to get the number of generators of the current symmetry group, respectively
2234- new API function SCIPdelNlRow() to remove a row from the NLP
2238- new event type SCIP_EVENTTYPE_NODEDELETE to react on nodes that are about to be deleted from the tree
2240### Changed parameters
2242- renamed parameter "propagating/orbitalfixing/enableafterrestart" to ".../symmetry/recomputerestart"
2243- Parameter "misc/allowdualreds" is now called "misc/allowstrongdualreds"
2244- Parameter "misc/allowobjprop" is now called "misc/allowweakdualreds"
2245- changed default values of propagation (new value: 1, old value: 5) and separation frequency (new value: -1, old value: 5) in cons_orbitope.c
2246- all primal heuristics that use sub-SCIPs are disabled within the heuristics fast emphasis setting
2247- deleted parameter heuristics/localbranching/useuct, use heuristics/useuctsubscip instead
2248- changed default value of "presolving/symbreak/detectorbitopes" (new value: TRUE, old value: FALSE)
2249- extended range of "misc/usesymmetry" (new range: [0,3], old range: [0,2])
2250- deleted parameter "constraints/orbisack/checkalwaysfeas"
2251- deleted parameter "constraints/orbitope/checkalwaysfeas"
2252- deleted parameter "constraints/symresack/checkalwaysfeas"
2253- deleted parameter "presolving/symmetry/maxgenerators"
2254- deleted parameter "presolving/symmetry/checksymmetries"
2255- deleted parameter "presolving/symmetry/displaynorbitvars"
2256- deleted parameter "presolving/symbreak/conssaddlp"
2257- deleted parameter "presolving/symbreak/addsymresacks"
2258- deleted parameter "presolving/symbreak/computeorbits"
2259- deleted parameter "presolving/symbreak/detectorbitopes"
2260- deleted parameter "presolving/symbreak/addconsstiming"
2261- deleted parameter "propagating/orbitalfixing/symcomptiming"
2262- deleted parameter "propagating/orbitalfixing/performpresolving"
2263- deleted parameter "propagating/orbitalfixing/recomputerestart"
2264- changed default value of "heuristics/coefdiving/freq" (old: 10, new: -1)
2265- changed default value of "heuristics/conflictdiving/freq" (old: -1, new: 10)
2266- changed default value of "heuristics/conflictdiving/lockweight" (old: 1.0, new: 0.75)
2267- replaced parameter "numerics/lpfeastol" by "numerics/lpfeastolfactor" to specify which factor should be applied to the SCIP feasibility
2268 tolerance to initialize the primal feasibility tolerance of the LP solver
2269- enabling aggressive presolving now activates all available presolving plugins,
2270 and decreases the presolving/restartfac parameter correctly with respect to default.
2271- changed default value of heuristics/rins/nodesquot to 0.3 (was 0.1), to compensate
2272 the removal of a hard coded factor of 3.0 in the code without affecting the default behavior
2273 of the RINS heuristic.
2274- changed default value of "constraints/quadratic/empathy4and" (old: 0, new: 2)
2275- changed default value of "propagating/redcost/useimplics" (old: TRUE, new: FALSE)
2279- the possibility to define the Benders' decomposition auxiliary variables as implicit integer is provided. This
2280 behavior is controlled with an additional parameter in the Benders' decomposition framework.
2281- added parameter benders/<bendersname>/cutcheck to enable the generation of Benders' decomposition cuts during solution
2283- constraints/orbitope/usedynamicprop: the possibility to propagate orbitope constraints by reordering the rows based on the
2284 branching strategy is provided (only possible for non-model constraints)
2286- new parameters heuristics/shiftandpropagate/minfixingratelp and heuristics/locks/minfixingratelp to stop the
2287 heuristics after propagating integer fixings if no sufficient fixing of the all variables (including continuous)
2288 could be achieved. These parameters help to avoid solving LP's that are comparable in hardness to the main root LP.
2290- Added parameters branching/midpull and branching/midpullreldomtrig to control by how much to move
2291 the branching point for an external branching candidate closer to the middle of the candidates domain. The
2292 default of 0.75 and 0.5, respectively, uses a point that is 75*alpha% closer to the middle of the domain, where
2293 alpha is the relative width of the candidates domain (width of local domain divided by width of global domain),
2294 if the latter is below 0.5, and alpha=1.0 otherwise. That is, with the default settings, a branching point is
2295 chosen closer to the middle of the candidates domain if the variables local domain is still similar to its
2296 global domain, but is chosen closer to the LP solution if the local domain is much smaller than the global
2299- Added parameter lp/minmarkowitz to set the Markowitz stability threshold (range 0.0001 to 0.9999).
2300 High values sacrifice performance for stability.
2302- Added parameters benders/<bendersname>/lnsmaxcalls and benders/<bendersname>/lnsmaxcallsroot to the Benders'
2303 decomposition core. These parameters limit the number of Benders' decomposition subproblem checks, for the full
2304 branch-and-bound tree and root node respective, when solving the auxiliary problem of LNS hueristics. These
2305 parameters only have effect if the lnscheck parameter is set to TRUE.
2307- Added parameter cons/linear/maxmultaggrquot to limit the maximum coefficient dynamism of an equation on which
2308 multiaggregation is performed. This replaces a compiler define of the same name.
2309 Default value is 1000, smaller values make multiaggregations numerically more stable.
2310- new global parameter heuristics/useuctsubscip that affects all LNS heuristics using common sub-SCIP parameters
2312- new parameter branching/relpscost/degeneracyaware to switch degeneracy-aware hybrid branching
2314- new parameter separation/rapidlearning/checkexec to check whether rapid learning is allowed to run locally
2315- new parameters separation/rapidlearning/check{degeneracy,dualbound,leaves,nsols,obj} to enable checking the respective feature for local rapid learning
2316- new parameter separation/rapidlearning/maxcalls to limit the number of rapid learning executions
2317- new parameter separation/rapidlearning/nwaitingnodes to set the number of waiting nodes before the dual bound is checked
2318- new parameter separation/rapidlearning/mindegeneracy to set the minimal threshold of degenerate basic-variables
2319- new parameters separation/rapidlearning/minvarconsratio to set the minimal ratio of unfixed variables in relation to basis size
2321- new parameters to control the Benders' decomposition two-phase method.
2322 - constraints/benderslp/depthfreq: after the maxdepth is reached, then the two-phase method will only be called at
2323 nodes at a depth divisible by depthfreq.
2324 - constraints/benderslp/stalllimit: after the maxdepth is reached, if there has been no improvement in the dual bound
2325 for stalllimit number of nodes, then the two-phase method is executed for the next fractional LP solution that is
2327 - constraints/benderslp/iterlimit: after the root node, only iterlimit fractional LP solutions are used at each node
2328 to generate Benders' decomposition cuts.
2330- new parameters for symmetry handling
2331 - new parameter "propagating/symmetry/maxgenerators"
2332 - new parameter "propagating/symmetry/checksymmetries"
2333 - new parameter "propagating/symmetry/displaynorbitvars"
2334 - new parameter "propagating/symmetry/conssaddlp"
2335 - new parameter "propagating/symmetry/addsymresacks"
2336 - new parameter "propagating/symmetry/detectorbitopes"
2337 - new parameter "propagating/symmetry/addconsstiming"
2338 - new parameter "propagating/symmetry/ofsymcomptiming"
2339 - new parameter "propagating/symmetry/performpresolving"
2340 - new parameter "propagating/symmetry/recomputerestart"
2341 - new parameter "constraints/symresack/checkmonotonicity"
2342 - new parameter "propagating/symmetry/compresssymmetries"
2343 - new parameter "propagating/symmetry/compressthreshold"
2344 - new parameter "propagating/symmetry/disableofrestart"
2345 - new parameter "propagating/symmetry/symfixnonbinaryvars"
2347- new parameter for enabling shared memory parallelisation for solving Benders' decomposition subproblems. The parameter
2348 benders/<bendersname>/numthreads sets the number of threads used for parallel subproblem solving.
2350- new parameters to control enhancements for solving MINLPs by Benders' decomposition
2351 - benders/<bendersname>/execfeasphase: enables the feasibility phase for solving the Benders' decomposition
2353 - benders/<bendersname>/slackvarcoef: the initial coefficient of the slack variable for the feasibility phase
2354 - benders/<bendersname>/checkconsconvexity: should the constraints be checked for convexity. This can be set to FALSE
2355 if you are certain that the NLP subproblem is convex.
2357- new parameter presolving/clqtablefac (default value 2.0) as limit on number of entries in clique table relative to number of problem nonzeros
2359- new parameter conflict/uselocalrows (default: TRUE) to incorporate locally valid cuts / rows for dual proof analysis
2361- new return code SCIP_NOTIMPLEMENTED for functions, e.g., in the LPI that have not been implemented (yet)
2363- new parameter separating/cgmip/genprimalsols that allows to generate initial primal solutions from Gomory cuts
2365- new parameter branching/relpscost/filtercandssym to allow filtering from orbits
2367- new parameter branching/relpscost/transsympscost to transfer pseudo cost information to orbit
2369- new parameters for tree size estimation and restarts:
2370 - estimation/restarts/restartpolicy (default value n)
2371 - estimation/method (default value c)
2372 - estimation/restarts/restartlimit (default value 1)
2373 - estimation/restarts/minnodes (default value 1000)
2374 - estimation/restarts/countonlyleaves (default value FALSE)
2375 - estimation/restarts/restartfactor (default value 2)
2376 - estimation/coefmonoprog (default value 0.3667)
2377 - estimation/coefmonossg (default value 0.6333)
2378 - estimation/restarts/hitcounterlim (default value 50)
2379 - estimation/reportfreq (default value -1)
2380 - estimation/regforestfilename (default value "-")
2381 - estimation/completiontype (default value a)
2382 - estimation/treeprofile/enabled (default value FALSE)
2383 - estimation/treeprofile/minnodesperdepth (default value 20)
2384 - estimation/useleafts (default value TRUE)
2385 - estimation/ssg/nmaxsubtrees (default value -1)
2386 - estimation/ssg/nminnodeslastsplit (default value 0)
2388- new parameter constraints/linear/extractcliques to turn clique extraction off
2390- new emphasis setting emphasis/numerics to increase numerical stability of (mostly) presolving operations such as (multi-)aggregations at the cost of performance.
2392- new parameters for treemodel:
2393 - new parameter branching/treemodel/enable to enable the treemodel in reliability pscost branching and possible
2394 future parts of the code where it could be used.
2395 - new parameter branching/treemodel/highrule to specify which branching rule to use when treemodel thinks the node
2396 is high in the tree.
2397 - new parameter branching/treemodel/lowrule to specify which branching rule to use when treemodel thinks the node
2399 - new parameter branching/treemodel/height to specify at which (estimated) height a node is high or low in the tree.
2400 - new parameter branching/treemodel/filterhigh to specify whether to filter dominated candidates in nodes which are
2402 - new parameter branching/treemodel/filterlow to specify whether to filter dominated candidates in nodes which are
2404 - new parameter branching/treemodel/maxfpiter to specify the maximum number of fixed-point iterations to use when
2405 computing the ratio of a variable using the fixed-point method.
2406 - new parameter branching/treemodel/maxsvtsheight to specify the maximum height to compute the SVTS score exactly
2407 before approximating it using the ratio.
2408 - new parameter branching/treemodel/fallbackinf defines the fallback strategy to use when the tree size estimates
2409 obtained by SVTS are infinite.
2410 - new parameter branching/treemodel/fallbacknoprim defines the fallback strategy to use when no primal bound is known
2411 and thus SVTS would not be able to compute a tree size (it would be infinite).
2412 - new parameter branching/treemodel/smallpscost defines the value under which pscosts are considered too small to be
2413 the deciding factor for branching, in which case it may be better not to use the treemodel.
2415- new parameters for symmetry handling constraint handlers to enforce that also non-model constraint are copied:
2416 - new parameter "constraints/orbisack/forceconscopy"
2417 - new parameter "constraints/orbitope/forceconscopy"
2418 - new parameter "constraints/symresack/forceconscopy"
2423- small changes in constants of hash functions
2424- added fast 2-universal hash functions for two to seven 32bit elements with 32bit output
2425- extended SCIPpqueueCreate() by additional callback argument SCIP_DECL_PQUEUEELEMCHGPOS to catch position changes
2426- new methods SCIPpqueueDelPos() to delete elements at a specific position in the priority queue and SCIPpqueueFind() to
2427 find a specific position. It is recommended to track position changes using the new callback SCIP_DECL_PQUEUEELEMCHGPOS.
2428 In contrast, using SCIPpqueueFind() can be slow because it needs to compare the element it searches for
2429 with each slot in the queue.
2433- The default value for DFLAGS in the non-cmake buildsystem has changed from -MM to -MMD. This will break the
2434 generation of depend.* files if that was done by a compiler call that relied on -MM. The new preferred way
2435 to handle compilation dependencies is to additionally use $(DFLAGS) when compiling the object files (.o) and
2436 to include the generated .d files in the Makefile, see also "Build system / Makefile" below.
2440 - new unit test for treemodel.
2445 - fixed an issue that may have lead to wrong status reports in the evaluation scripts
2452- avoid problem with doubly defined object together with CPLEX
2456- Removed static object compilation dependency files (depend.*). If using a GCC compatible compiler, then dependency
2457 files are now dynamically created and updated during build. The new dependency files (*.d) reside next to each object
2458 file (.o) in the corresponding obj subdirectory.
2459- added support for building against Ipopt >= 3.13
2460- unify compiler switches for Intel compiler and avoid problem with doubly defined object together with CPLEX
2465- fix and improve memory handling in symmetry computation
2466- fix shown number of applied conflicts in solving statistics
2467- fix wrongly skipping strong branching call and using old information if LP was solved with 0 iterations
2468- fix minor bug in cut score calculation
2469- fixed several bugs related to rounding locks of variables not being updated correctly
2470- small fix in cons_varbound.c to skip changing bounds of multi-aggregated variables in separation callback
2471- fixed issue in SCIPtightenVar* and SCIPinferVar* that occurs for small bound changes
2472- fixed rejecting minimal boundchange that changed sign of variable, even though SCIPisLb/UbBetter approved it
2473- fixed issue in generateCutNonConvex() which is triggered when adding quadratic constraints during the solving process
2474- fixed bug in freeing the reoptimization data if no problem exists
2475- fixed bug in SCIPreoptReleaseData() when freeing all stored constraints
2476- fixed bug when freeing the transformed problem via interactive shell if reoptimization is enabled
2477- fixed two issues related to (near-)redundant logicor constraints in presolving
2478- fixed counting of aggregations in XOR constraint handler
2479- fixed handling of unbounded solutions
2480- fixed update of LP size information when an LP error occured during probing
2481- handle special case of variable bound constraints during aggregating variables
2482- tighten sides of linear constraints before trying to upgrade them to more specialized constraints (knapsack, logic-or etc.) when calling SCIPupgradeConsLinear()
2483- fixed an issue in repair heuristic in the case of loose (noncolumn) variables
2484- allow user to correctly set heuristics/alns/(un)fixtol
2485- fixed an issue in heur_completesol which is triggered during bound widening of unbounded continuous variables
2486- fixed bug in cons_indicator if addopposite is true
2487- fixed bug in sepa_disjunctive: treat case that conflictgraph is empty
2488- added safety check in conversion to rational number to avoid overflow
2489- fixed bug in interval evaluation with power-operator in certain situations
2490- fixed behavior of SCIPmatrixCreate() regarding memory management and column generation
2491- SCIPmatrixCreate() returns complete=FALSE when locks do not add up
2492- fixed bug in sepa_oddcylce when variables are fixed
2493- fixed numerical issues related to tighter constraint sides in varbound constraint handler
2494- fixed update of watchedvars in logicor constraint handler in case of a restart during the tree
2495- fixed treatment of multi-aggregated variables in logicor constraint handler
2496- handle special case of redundant implications
2497- fixed numerical issue related to almost-0-values in pseudosolution conflict analysis
2498- fixed numerical issue related to very large greatest common dividers in linear constraint handler
2499- avoid using implications on multiaggregated variables when propagating implications
2500- fixed creation of (Lagrangian) variable bounds in the OBBT propagator
2501- fixed sorting of primal solutions
2502- fixed cleaning of clean buffer in conflict analysis
2503- avoid probing on variables with huge bounds in shift and propagate heuristic
2504- fix issue in printing solutions for variables that have been added by the dual sparsify presolver
2505- fix issue related to fixing redundant logic-or constraints after presolving
2506- fixed bug when parsing logic-or and and-constraints
2507- fixed wrong assert in updateLazyBounds()
2508- fixed bug in pricestore, which resulted in too many problem variables being added
2509- fixed bug in cons_knapsack where weight of clique was not reset after an infeasibility was detected
2510- fixed bug in presol_inttobinary which did not take into account that the aggregation could be rejected due to numerics
2511- fixed bug in debug solution mechanism in connection to variables created by presol_inttobinary
2512- fixed wrong indexing while undoing the implications from a redundant variable in SCIPshrinkDisjunctiveVarSet
2513- redundancy checks in SCIPnodeAddBoundinfer now take a possible change to an active variable into account
2514- fixed adding already added quadratic rows to NLP relaxation during solve
2515- fixed issue related to variable locks in the varbound constraint handler
2516- fixed bug in the quadratic constraint handler when changing infinite constraint sides
2517- fixed sorting of variables in linear constraint handler
2518- added additional checks to ensure numerical stability of dual proofs
2519- fixed a case when activities of a linear constraint got unreliable but where still used for reductions
2520- ensure that lhs <= rhs for linear constraints (without tolerances)
2521- make handling of read errors in SCIPfread() consistent between version with and without ZLIB
2522- correctly drop variable events in cons_indicator in restart
2523- fixed bug in cons_orbitope with upgrading of orbitope constraints
2524- additional checks in some presolvers for time limit being exceeded
2525- fixed bug in presolving of cons_varbound with multi-aggregated variables
2526- improve numerics in conflict analysis by using double-double arithmetic
2527- fixed bound acceptance condition to avoid inconsistencies
2528- fixed numerics in pseudoobj propagator by using double-double arithmetic
2533- modified display column for memory usage ("mem"), which reports the memory usage most of the time, but shows the creator name
2534 (heuristic, relaxation handler, LP relaxation, strong branching, pseudo solution) of every new incumbent solution. Together with this change,
2535 heuristic display characters have been unified to represent the type of the heuristic
2536 (diving, Large neighborhood search, propagation, etc.), see also type_heur.h.
2537- added assert that ensures that the locks of a variable have been decreased to 0 when it is freed
2538- added more output for completing a partial solution
2539- checks in debug mode that clean buffer memory is really clean when being freed are now disabled by default
2540- don't compute symmetries if reoptimization is enabled
2541- prefer integral values when fixing an almost-fixed continuous variable in the trivial presolver
2542- changed the name of the variable that is added by the OSiL reader to represent the quadratic or nonlinear parts of the objective function
2543- SCIP_EXPORT is now defined as __attribute__((__visibility__("default"))) if GCC and no SCIP config header is used
2545@page RN6 Release notes for SCIP 6
2547@section RN602 SCIP 6.0.2
2548*************************
2553- The abspower constraint handler now passes more accurate convexity
2554 information to the NLP relaxation.
2556Examples and applications
2557-------------------------
2559- added parsing functionality for optcumulative constraints in CIP format
2564### Interfaces to external software
2566- Updated the Mosek LP solver interface to support Mosek 9.0.
2573- new target to 'doc' to build documentation
2574- ctests now fail if parameter file not found
2575- add flag STATIC_GMP and improve GMP find module
2576- remove non-API methods from library (API methods use new macro SCIP_EXPORT)
2577- increase minimal required CMake version to 3.3
2578- correct paths and dependency information when installing SCIP
2582- fixed SCIP-Jack presolving bug that could lead to wrong results for Steiner arborescence problems
2583- fixed wrong unboundedness result in case not all constraints were already in the LP and enforcement was
2584 skipped because an optimal solution was found
2585- fixed wrong enforcement of constraints in the disjunction constraint handler
2586- fixed wrong behavior of concurrent solve ignoring initial solutions
2587- fixed bug in concurrent solve when problem was already solved in presolving
2588- aggregate non-artificial integer variable for XOR constraints with two binary variables and delete constraint
2589- copy the objective offset when copying the original problem
2590- fixed bug in SCIPlpiGetBInvARow in lpi_cpx using wrong size of resulting vector
2591- fixed quadratic runtime behavior in sepa_aggregation
2592- fixed statistics of separators
2593- improve numerical stability in varbound constraint handler by using double-double arithmetic
2594- fixed bug in propagation of dual proofs
2595- fixed bugs that arise for multiaggregated indicator variables by disallowing multiaggregation for them
2596- improve numerical stability in SCIPcomputeBilinEnvelope* by using double-double arithmetic
2597- fixed bug related to releasing pending bound changes in tree.c
2598- set STD FENV_ACCESS pragma to on in code that changes floating-point rounding mode
2599- disable GCC optimizations in main interval arithmetic code to prevent wrong optimizations
2600- fixed wrong assert in cons_xor concerning the variable type
2601- fixed different behavior of SCIPisLbBetter and SCIPisUbBetter between having NDEBUG defined or not
2602- correctly handle bound disjunctions in symmetry detection
2603- fixed issue in reliability branching related to the LP error flag not being reset
2604- fixed treatment of near-infinite bounds in shiftandpropagate's problem transformation
2605- fixed handling of infinite values in SCIPcomputeHyperplaneThreePoints()
2606- fixed comparisons of infinite values in heur_intshifting.c and heur_shifting.c
2607- fixed bug related to updating unprocessed cuts in the cutpool
2608- fixed bug related to enabling quadratic constraints during `CONSINITLP`
2609- add missing SCIP_EXPORT for functions used by GCG
2610- fixed memory leak and wrong initialization for trival cases in cons_symresack.c
2611- fixed bug with upgrading to packing/partitioning orbitopes
2612- fixed bug with the status while upgrading in presol_symbreak.c
2613- fixed wrong stage while clearing the conflict store
2614- fixed behavior of SCIPfixVar() by setting infeasible pointer to TRUE if fixval lies outside variable domain
2615- allow tightenVar() in SCIP_STAGE_PROBLEM stage
2616- fixed bug in cumulative constraint handler when separating the LP solution
2617- fixed issues with integer overflow in cumulative constraint handler
2618- fixed bug where the convexity of Benders' decomposition subproblems was checked even when users defined subproblem
2619 solving methods. Now, as per the documentation, the user must explicitly state whether the subproblem is convex
2620- fixed wrong indexing in heur_dualval
2621- fixed issue with basis status in SoPlex LPi
2626- statistics now output primal/dual bounds if objective limit is reached
2627- memory check in debug mode is now disabled by default
2628- message is now provided to the user to inform that automatic Benders' auxiliary variable lower bound computations are
2629 not activated when user defined subproblem solving methods are present
2630- corrected documentation of the primalgap in SCIP; describe when it will be infinite
2632@section RN601 SCIP 6.0.1
2633*************************
2638- when using a debug solution every (multi-)aggregation will be checked w.r.t. this solution
2640Performance improvements
2641------------------------
2643- try greedy solution first before solving knapsack exactly using dynamic programming in SCIPsolveKnapsackExactly,
2644 compute greedy solution by weighted median selection.
2645- don't consider implied redcost by default in the reduced cost propagator
2650### Deleted and changed API methods and macros
2652- The preprocessor macro NO_CONFIG_HEADER now needs to be defined when
2653 including SCIP header files from a SCIP build or installation that
2654 has been build via the Makefile-only build system.
2656- The following preprocessor macros have been renamed:
2657 WITH_ZLIB to SCIP_WITH_ZLIB, WITH_GMP to SCIP_WITH_GMP, WITH_READLINE
2658 to SCIP_WITH_READLINE, NO_SIGACTION to SCIP_NO_SIGACTION, NO_STRTOK_R
2659 to SCIP_NO_STRTOK_R, ROUNDING_FE to SCIP_ROUNDING_FE, ROUNDING_FP to
2660 SCIP_ROUNDING_FP, ROUNDING_MS to SCIP_ROUNDING_MS. Note, however, that
2661 the names of macros NO_RAND_R and NO_STRERROR_R have not been changed
2664### New API functions
2666- SCIPhashmapInsertInt(), SCIPhashmapSetImageInt(), and SCIPhashmapGetImageInt() to use integer values as images in hashmaps
2668### Command line interface
2670- warn about coefficients in MPS files with absolute value larger than SCIP's value for infinity
2672### Changed parameters
2674- default clock type for timing is now wallclock
2679- added unit tests for exact knapsack solving and (weighted) median selection algorithms
2686- add missing GMP dependency when compiling with SYM=bliss
2687- add DL library when linking to CPLEX to avoid linker errors
2688- new config.h header defining the current build configuration, e.g. SCIP_WITH_GMP
2693- fixed handling of weights in cons_sos1 and cons_sos2 (NULL pointer to weights)
2694- fixed handling of unbounded LPs in SCIP and in several LPIs; added heuristic method to guess solution
2695- the STO reader is capable of handling scenarios defined using lower case "rhs"
2696- fixed OPB reader for instances without explicit plus signs
2697- correct dual solution values for bound constraints
2698- fixed recognition of variable with only one lock in cons_bivariate, cons_quadratic, and cons_nonlinear
2699- fixed update of constraint violations in solution repair in cons_bivariate, cons_quadratic, and cons_nonlinear
2700- print error message and terminate if matrix entries of a column are not consecutive in mps format
2701- fixed incorrect handling of fixed variables when transfer of cuts from LNS heuristic for Benders' decomposition
2702- fix returning local infeasible status by Ipopt interface if Ipopt finds problem locally infeasible
2703- skip attempt to apply fixings in linear constraint handler during solving stage as LP rows cannot change anymore
2704- fixed bug when reading >= indicator constraints in MPS format
2705- fix issue with nodes without domain changes if we ran into solution limit in prop_orbitalfixing
2706- fixed unresolved reference to CppAD's microsoft_timer() function on builds with MS/Intel compilers on Windows
2707- ignore implications added through SCIPaddVarImplication() that are redundant to global bounds also in the
2708 special case of an implication between two binary variables; also, use implications instead of cliques in the case
2709 of a binary implied variable with nonbinary active representative
2710- fixed bug with aggregated variables that are aggregated in propagation of cons_sos1
2711- fixed some special cases in SCIPselect/SCIPselectWeighted methods
2712- relaxed too strict assertion in Zirounding heuristic
2713- fixed the upgrade routine to XOR constraints: aggregate integer variable if its coefficient has the wrong sign
2714- fixed handling of nonartificial parity variables when deleting redundant XOR constraints
2715- earlier deletion of trivial XOR constraints (at most 1 operator left)
2716- fixed wrong hashmap accesses and added sanity check for the correct hashmap type
2717- avoid copying of unbounded solutions from sub-SCIPs as those cannot be checked completely
2718- corrected the output of the first LP value in case of branch-and-price
2719- fixed possible integer overflow, which led to wrong conclusion of infeasibility, in energetic reasoning of cons_cumulative.c
2724- do not scale linear constraints to integral coefficients
2726@section RN600 SCIP 6.0.0
2727*************************
2732- new diving heuristic farkasdiving that dives into the direction of the pseudosolution and tries to construct Farkas-proofs
2733- new diving heuristic conflictdiving that considers locks from conflict constraints
2734- restructuring of timing of symmetry computation that allows to add symmetry handling components within presolving
2735- `lp/checkstability` is properly implemented for SoPlex LPI (spx2)
2736- new branching rule lookahead that evaluates potential child and grandchild nodes to determine a branching decision
2737- limits on the number of presolving rounds a presolver (maxrounds) or propagator/constraint handler (maxprerounds)
2738 participates in are now compared to the number of calls of the particular presolving method, not the number of
2739 presolving rounds in general, anymore
2740- new miscellaneous methods for constraints that have a one-row linear representation in pub_misc_linear.h
2741- a Benders' decomposition framework has been added. This framework provides the functionality for a user to solve a
2742 decomposed problem using Benders' decomposition. The framework includes classical optimality and feasibility cuts,
2743 integer optimality cuts and no-good cuts.
2744- add statistic that presents the number of resolves for instable LPs
2745- new readers for stochastic programming problems in SMPS format (reader_sto.h, reader_smps.h)
2747Performance improvements
2748------------------------
2750- cuts generated from certain quadratic constraints with convex feasible region are now global
2751- performance improvements for Adaptive Large Neighborhood Search heur_alns.c
2752 + all neighborhoods now start conservatively from maximum fixing rate
2753 + new default parameter settings for bandit selection parameters
2754 + no adjustment of minimum improvement by default
2755- improved bound tightening for some quadratic equations
2756- constraint handler checking order for original solutions has been modified to check those with negative check priority
2757 that don't need constraints after all other constraint handlers and constraints have been checked
2758- deactivate gauge cuts
2760Examples and applications
2761-------------------------
2763- new example `brachistochrone` in CallableLibrary examples collection; this example implements a discretized model to
2764 obtain the trajectory associated with the shortest time to go from point A to B for a particle under gravity only
2765- new example `circlepacking` in CallableLibrary examples collection; this example models two problems about packing
2766 circles of given radii into a rectangle
2767- new price-and-branch application for the ringpacking problem
2768- new stochastic capacitated facility location example demonstrating the use of the Benders' decomposition framework
2773### New and changed callbacks
2775- added parameter locktype to `SCIP_DECL_CONSLOCK` callback to indicate the type of variable locks
2777### Deleted and changed API methods
2780 + removed function SCIPgetTimingSymmetry() in presol_symmetry.h since this presolver does not compute symmetries independent
2781 of other components anymore
2782 + additional argument `recompute` to SCIPgetGeneratorsSymmetry() to allow recomputation of symmetries
2785 + the seed of SCIPinitializeRandomSeed() is now an unsigned int
2786 + the seed of SCIPsetInitializeRandomSeed() is now an unsigned int and it returns an unsigned int
2787 + new parameter for SCIPcreateRandom() to specify whether the global random seed shift should be used in the creation of
2788 the random number generator
2791 + additional arguments `preferrecent`, `decayfactor` and `avglim` to SCIPcreateBanditEpsgreedy() to choose between
2792 weights that are simple averages or higher weights for more recent observations (the previous default).
2793 The last two parameters are used for a finer control of the exponential decay.
2794 + functions SCIPintervalSolveUnivariateQuadExpression(), SCIPintervalSolveUnivariateQuadExpressionPositive(), and
2795 SCIPintervalSolveUnivariateQuadExpressionPositiveAllScalar() now take an additional argument to specify already
2796 existing bounds on x, providing an entire interval ([-infinity,infinity]) gives previous behavior
2798### New API functions
2800- SCIPintervalSolveUnivariateQuadExpressionNegative()
2801- SCIPvarGetNLocksDownType() and SCIPvarGetNLocksUpType()
2802- SCIPaddConsLocksType()
2803- SCIPconsIsLockedTypePos(), SCIPconsIsLockedTypeNeg(), SCIPconsIsLockedType(), SCIPconsGetNLocksTypePos() and SCIPconsGetNLocksTypeNeg()
2804- SCIPstrncpy(), a safe version of strncpy()
2806### Changed parameters
2808- Removed parameters:
2809 - `heuristics/alns/stallnodefactor` as the stall nodes are now controlled directly by the target node limit within the heuristic
2810 - `presolving/symmetry/computepresolved` since this presolver does not compute symmetries independent of other components anymore
2811 - `separating/maxincrounds`
2815- `lp/checkfarkas` that enables the check of infeasibility proofs from the LP
2816- `heuristics/alns/unfixtol` to specify tolerance to exceed the target fixing rate before unfixing variables, (default: 0.1)
2817- `propagating/orbitalfixing/symcomptiming` to change the timining of symmetry computation for orbital fixing
2818- `lp/alwaysgetduals` ensure that the dual solutions are always computed from the recent LP solve
2819- `display/relevantstats` indicates whether the small relevant statistics are displayed at the end of solving
2820- `propagating/orbitalfixing/performpresolving` that enables orbital fixing in presolving
2821- `presolving/symbreak/addconsstiming` to change the timining of symmetry computation for symmetry handling inequalities
2822- `propagating/orbitalfixing/enabledafterrestarts` to control whether orbital fixing is enabled after restarts
2823- `benders/∗` new submenu for Benders' decomposition related settings. This includes the settings related to the
2824 included Benders' decompositions and the general Benders' decomposition settings.
2825- `benders/<decompname>/benderscuts/∗` submenu within each included Benders' decomposition to control the Benders'
2826 decomposition cuts. The cuts are added to each decomposition separately, so the setting are unique to each
2831- new enum `SCIP_LOCKTYPE` to distinguish between variable locks implied by model (check) constraints (`SCIP_LOCKYPE_MODEL`)
2832 and variable locks implied by conflict constraints (`SCIP_LOCKYPE_CONFLICT`)
2833- expression interpreter objects are now stored in the block memory
2838- removed presolving plugin presol_implfree
2839- separated scip.c into several smaller implementation files scip_*.c for better code overview; scip.c was removed,
2840 but the central user header scip.h remains, which contains includes of the separated headers
2845- fixed bug in gcd reductions of cons_linear regarding an outdated flag for variable types
2846- fixed bug in heur_dualval regarding fixing routine for integer variables
2847- suppress debug solution warnings during problem creation stage
2848- fixed check for activated debugging solution in components constraint handler
2849- fixed potential bug concerning solution linking to LP in SCIPperformGenericDivingAlgorithm()
2850- fixed reward computation in ALNS on continuous, especially nonlinear, problems
2851- fixed bug in freeing reoptimization data if problem was solved during presolving
2852- fixed check of timing in heur_completesol
2853- fixed wrong propagation in optcumulative constraint handler
2854- fixed non-deterministic behavior in OBBT propagator
2855- don't disable LP presolving when using Xpress as LP solver
2856- fixed possible `NULL` pointer usage in cons_pseudoboolean
2857- ensured that SCIPgetDualbound() returns global dual bound instead of the dual bound of the remaining search tree
2858- fixed rare division-by-zero when solving bivariate quadratic interval equation
2859- use total memory for triggering memory saving mode
2860- fix parsing of version number in the CMake module for Ipopt
2861- fixed handling of implicit integer variables when attempting to solve sub-MIP in nlpdiving heuristic
2862- added workaround for bug when solving certain bivariate quadratic interval equations with unbounded second variable
2863- fixed bug with releasing slack variable and linear constraint in cons_indicator
2864- fixed problem when writing MPS file with indicator constraints with corresponding empty linear constraints
2865- fixed bug in heur_vbound triggered when new variables were added while constructing the LP
2866- fixed bug with unlinked columns in SCIProwGetLPSolCutoffDistance()
2871- updated CppAD to version 20180000.0
2872- remove LEGACY mode, compiler needs to be C++11-compliant
2874@page RN5 Release notes for SCIP 5
2876@section RN501 SCIP 5.0.1
2877*************************
2882- SCIP executable handles the `SIGTERM` signal. If the process receives a `SIGTERM`, SCIP terminates the solution process with a
2883 new `SCIP_STATUS` code `SCIP_STATUS_TERMINATE` and displays all relevant statistics before exiting.
2884- add number of conflict constraints found by diving heuristics to statistics
2885- allow output of lower bounds for visualization
2886- added symmetry detection for linking constraints
2888Performance improvements
2889------------------------
2891- disable disaggregation of quadratic constraints by changing the default for `constraints/quadratic/maxdisaggrsize` to 1
2892 (disaggregation can still be very helpful on some instances, but also seems hurtful on others)
2895 - increased threshold when to scale up cuts that are generated by nonlinear constraint handlers
2896 - test additional scaling factors in CMIR cut generation heuristic
2897 - cleaned up implementation of the cut selection procedure and added new cut quality measure
2898 - use random tie-breaking in cut selection
2903### New API functions
2905- new methods SCIPtryTerminate() and SCIPterminated() in scip/interrupt.h for handling of SIGTERM signals.
2906- new method SCIPselectCuts() to run SCIP's cut selection procedure on a given array of cuts
2908### Changed parameters
2910- rename parameter `constraints/orbisack/orbisack/coverseparation` to `constraints/orbisack/coverseparation`
2914- `visual/displb` that enables output of lower bounds for visualization
2915- `presolving/symmetry/displaynorbitvars` (whether we display the number of affected variables in the statistics)
2916- `separating/efficacyfac` to change the weight of the efficacy in cut score calculation
2917- `separating/dircutoffdistfac` to change the weight of the directed cutoff distance in cut score calculation
2921- new `SCIP_STATUS` code `SCIP_STATUS_TERMINATE` in scip/interrupt.h for handling of SIGTERM signals.
2926- expanded unit tests of the lpis
2927- added check to unit tests that problem is not solved after every change
2932- fixed LP status to unsolved when marking LP to be resolved if objective limit has changed
2933- copy parameter settings to sub-SCIPs in SCIPcopyLargeNeighborhoodSearch() also when copying only LP rows
2934- fixed a check for fixed variables in Binpacking example
2935- generate deprecation warnings when using SCIPaddCut
2936- fix bug in sepa_gomory if cut is a bound change
2937- fixed handling of infinite bounds in cons_sos1
2940 - fixed bug while scaling linear constraints
2941 - don't delete conflict constraints that were transformed into model constraints during a restart
2942 - fixed treatment of variable aggregations in knapsack constraint handler that led to wrong propagations
2945 - fixed LPI status after changing objective in lpi_cpx, lpi_grb, lpi_xprs, lpi_msk
2946 - fixed and unified asserts in LPIs
2947 - retrieve interior solution instead of (possibly non-existing) basic solution from mosek after using barrier without crossover in lpi_msk
2948 - fixed bug with `NULL` pointer handling in LPIs
2951 - fixed wrong cast in LP iteration limit computation in proximity search heuristic
2952 - fixed check for time limit in heur_nlpdiving
2953 - improved numerics and fixed stop criterion in zirounding heuristic
2955@section RN500 SCIP 5.0.0
2956*************************
2961- new numerical solution violations get printed when checksol is called
2962- added analysis of the clique table which identifies possible aggregations via the search for
2963 strongly connected components and may detect infeasible assignments on the way
2964- added macros to do computations with a higher precision by using double-double arithmetic
2965- extended conflict analysis by analyzing dual solutions of boundexceeding LPs
2966- revised internal debugging mechanism to check against a user given debug solution (debug.h)
2969 - add new heuristic MPEC that solves a MPEC reformulation of a mixed-binary nonlinear problem by regularized NLP reformulations
2970 - new primal heuristic ALNS that orchestrates eight different LNS heuristics adaptively
2971 using algorithms for the multi-armed bandit problem
2972 - three bandit selection algorithms to face sequential decision problems under uncertainty
2974- Presolving and symmetry:
2975 - added presol_symmetry.c for computing and storing symmetry information of a MIP
2976 - added presol_symbreak.c to detect special symmetry structures and to add symmetry handling constraints
2977 - SCIP can now automatically detect and compute symmetries in MIPs (if a graph automorphism code is linked in)
2978 - added cons_symresack.c to handle permutation symmetries in a binary programs via inequalities and propagation
2979 - added cons_orbisack.c to handle special permutation symmetries in a binary programs via inequalities and propagation
2980 - cons_orbitope.c can now handle full orbitopes as well
2983 - added new propagator orbital fixing
2984 - utilizing linear inequalities to compute stronger linearizations for bilinear terms; the inequalities are computed in
2988 - added API for aggregating rows for generating cuts which uses double-double arithmetic internally
2989 - added filtering of parallel cuts in the cut pool
2992 + added new plugin type `table` for adding user-defined statistics tables
2993 + new presolving plugin presol_sparsify that tries to cancel nonzero coefficients in linear constraints by adding
2994 multiples of linear equalities
2996Performance improvements
2997------------------------
2999- use disjoint set to reduce peak memory usage and time to compute of clique table connectedness information
3000- add and use RESTRICT macro for some pointers
3001- improved the implementation of SCIPvarGetActiveRepresentatives
3002- speed-up reverse propagation
3003- removed bestrelaxsol and directly access relaxation solution instead to decrease overhead when using relaxation handlers
3004- for fast presolving emphasis, disable use of implications in logicor presolving
3005- use limit on the total number of nonzeros added to the clique table during the greedyCliqueAlgorithm of cons_knapsack.c
3006- revised disaggregation of quadratic constraints: the number of created constraints can now be controlled and the
3007 disaggregated constraints are scaled in order to increase numerical accuracy
3008- disabled reformulation of products of a binary variable with a linear term that does not solely involve binary variables
3009- speed up creation of LP in the computation of relative interior points
3010- improved dual ray analysis
3011- drop events of disabled linear constraints to reduce event processing effort
3014 - new implementation of zerohalf separator
3015 - enabled cutting plane separation in the tree
3016 - improved cut selection and management
3017 - improved cut post-processing: apply coefficient tightening, enforce maximal dynamism
3020 - improved selection of rows in CMIR aggregation heuristic
3021 - generate lifted flowcover cuts in CMIR cut generation heuristic
3022 - faster implementation of CMIR cut generation heuristic
3023 - use LP solution polishing during probing and diving mode to activate it during many primal heuristics; remains disabled
3024 during strong branching and OBBT
3025 - improved versions of the clique and variable bound pre-root heuristics that are often able to fix many more variables
3030### New and changed callbacks
3033 - added new abstract selection algorithm `SCIP_BANDIT` together with callbacks
3034 - added new types for symmetry handling
3037 - dropped NLP termination status `SCIP_NLPTERMSTAT_UOBJLIM`
3040 - added parameter `objval` to `SCIP_DECL_NLPIGETSOLUTION` for returning the optimal objective value (can be set to `NULL`)
3042- Separation callbacks:
3043 - added parameter `allowlocal` to `SCIP_DECL_SEPAEXECLP` and `SCIP_DECL_SEPAEXECSOL` to switch generation of locally valid cuts
3044 - added parameter `dstatssize` to `SCIP_DECL_NLPIDELVARSET` and `SCIP_DECL_NLPIDELCONSSET`
3046### Deleted and changed API methods
3049 - removed parameter `allowaddcons` from SCIPselectVarPseudoStrongBranching(), SCIPselectVarStrongBranching(), and
3050 SCIPincludeBranchruleRelpscost()
3052- Constraint Handlers:
3053 - generalized SCIPcreateConsOrbitope() and SCIPcreateConsBasicOrbitope() method to three orbitope types (full, partitioning, packing)
3055- Cutting plane separation methods:
3056 - changed function signature of SCIPcalcMIR()
3057 - changed function signature of SCIPcalcStrongCG()
3058 - new method SCIPaddRow() to replace deprecated SCIPaddCut()
3059 - removed parameter `scaling` from SCIPgetRowprepViolation()
3060 - added parameter `allowlocal` to SCIPseparateSol()
3063 - replaced LP parameters `SCIP_LPPARAM_LOBJLIM` and `SCIP_LPPARAM_UOBJLIM` by `SCIP_LPPARAM_OBJLIM`
3066 - SCIPnlpStatisticsCreate() and SCIPnlpStatisticsFree() now require a pointer to blockmemory as parameter
3067 - added parameter `objval` to SCIPnlpiGetSolution() of NLPIs for returning the optimal objective value (can be set to `NULL`)
3068 - added parameter `varnameslength` to SCIPexprParse()
3069 - added parameter `dstatssize` to SCIPnlpiDelVarSet() and SCIPnlpiDelConsSet()
3070 - added modifier const to `exprtree` parameter of SCIPnlpiChgExprtree()
3073 - SCIPheurPassIndicator() has a new parameter which allows to pass the objective of the solution
3076 - added parameter `includeslp` to SCIPmarkRelaxSolValid(), SCIPsetRelaxSolVals() and SCIPsetRelaxSolValsSol();
3077 - removed parameter `includeslp` from SCIPrelaxCreate() and SCIPincludeRelax()
3078 - removed functions SCIPrelaxIncludesLp() and SCIPrelaxSetIncludesLp()
3079 - replaced method SCIPgetRelaxFeastolFactor() by SCIPrelaxfeastol() and added SCIPchgRelaxfeastol()
3082 - changed return type of SCIPcliqueGetId() from `int` to `unsigned int`
3083 - removed SCIPvarGetCliqueComponentIdx(); the connectedness information of the clique table is now stored as a
3084 `SCIP_DISJOINTSET` member of the clique table and cannot be publicly accessed
3085 - added parameter `copytables` to SCIPcopyPlugins()
3086 - SCIPsolveParallel() has been deprecated, use the new method SCIPsolveConcurrent() instead
3087 - allowed SCIPgetNConss() in stage `SCIP_STAGE_INITSOLVE`
3089### New API functions
3091- SCIPaddRow() to replace deprecated SCIPaddCut()
3092- methods to display linear constraint classification types; use SCIPclassifyConstraintTypesLinear()
3093 after reading a problem to classify linear constraint types
3094- public methods SCIPvariableGraphBreadthFirst() and SCIPvariableGraph{Create,Free}() to
3095 perform breadth-first search on the variable constraint graph used by the GINS and ALNS heuristics
3096- SCIPsetProbingLPState() to install given LP state and/or norms at the current probing node
3097- SCIPbranchcandGetLPMaxPrio() and SCIPbranchcandGetExternMaxPrio() to query the maximal branching priority of given
3098 branching candidates; also added SCIPbranchcandGetNPrioLPCands() to access the number of LP candidates with this priority.
3099- SCIPupdateSolIntegralityViolation(), SCIPupdateSolBoundViolation(), SCIPupdateSolLPRowViolation(),
3100 SCIPupdateSolConsViolation() and SCIPupdateSolLPConsViolation() for updating numerical solution violations, as well as
3101 SCIPactivateSolViolationUpdates() and SCIPdeactivateSolViolationUpdates() for activating/deactivating violation updates globally
3102- SCIPsetSubscipDepth() to set the depth of SCIP as a copied subproblem during problem stage
3103- SCIPdivesetGetNSols() to query the number of found solutions from a diveset.
3104- SCIPnextafter() that wraps different nextafter methods to return the next representable value after a given value
3105- SCIPlinConsStats{Create,Free,GetTypeCount,GetSum}() and SCIPprintLinConsStats() to work with linear constraint classification through the C API
3106- SCIPgetRowNumIntCols() that returns the number of integer columns in a row
3107- SCIPsetSlackVarUb() to control upper bound of slack variable in cons_indicator
3110 - methods SCIPrandomCreate() and SCIPrandomFree() are no longer public and should be replaced by SCIPcreateRandom() and
3111 SCIPfreeRandom(), respectively (the new methods respect the global parameter `randomization/randomseedshift` automatically)
3112 - methods SCIPdigraphCreate() and SCIPdigraphCopy() are no longer public and should be replaced by SCIPcreateDigraph() and
3113 SCIPcopyDigraph(), respectively, which receive a SCIP argument and are more robust towards future interface changes
3116 - SCIPgetAllBilinearTermsQuadratic() to access data of all existing bilinear terms in quadratic constraints
3117 - SCIPaddBilinearIneqQuadratic() to propose an inequality with two variables that appear in a bilinear term
3118 - SCIPcomputeBilinEnvelope{1,2}() to compute a linearization of a bilinear term when considering at most two linear inequalities
3121 - SCIPcliqueGetIndex() which returns the unique identifier for the given clique
3122 - SCIPgetNCliquesCreated() which returns the number of cliques created so far
3124- Cutting plane separation methods:
3125 - SCIPisCutNew() that returns whether a cut is already present in the global cut pool
3126 - SCIPgetSepaMinEfficacy() to access separating/minefficacy(root)
3129 - interface methods to create and use bandit algorithms implemented as SCIP core plugins
3130 - interface methods for aggregating rows and computating MIP cuts, see cuts.h
3131 - interface method SCIPsetRandomSeed() to (re)set a random number generator seed
3133### Command line interface
3135- new interactive shell functionality to display linear constraint classification types;
3136 use `display linclass` after reading a problem to classify linear constraint types
3137- new command line parameter `-r` to pass a nonnegative integer as random seed.
3139### Interfaces to external software
3141- added interface to the NLP solver WORHP
3142- added interface to the NLP solver FilterSQP
3143- added interface to graph automorphism algorithms in `src/symmetry/` (initially only to BLISS)
3144- unify handling of objective limit in LPIs by replacing LPI parameters `SCIP_LPPAR_LOBJLIM` and `SCIP_LPPAR_UOBJLIM` by
3146- dropped support for MOSEK < 7.0.0.0
3148### Changed parameters
3150- changed and removed several parameters for zerohalf separator
3151- replaced `constraints/quadratic/disaggregate` by `constraints/quadratic/maxdisaggrsize` to bound
3152 the total number of created constraints when disaggregating a quadratic constraint
3153- new value 3 for parameter `lp/solutionpolishing` to enable LP polishing only during probing and diving mode
3154- parameter `conflict/useboundlp` has new values `d` (only dual solution analysis) and `b` (both, conflict and dual solution analysis)
3157 - fixed typo `heuristics/completesol/maxunkownrate` has changed to `heuristics/completesol/maxunknownrate`
3158 - replaced parameter `heuristics/{clique,vbounds}/minfixingrate` by `heuristics/{clique,vbounds}/minintfixingrate` and
3159 `heuristics/{clique,vbounds}/minmipfixingrate`, which check the fixing rate before LP solving and after sub-MIP presolve
3162 - parameter `separating/maxstallrounds` only applies to nodes in the tree (not the root node, anymore); use the new
3163 parameter `separating/maxstallroundsroot` for the root node
3164 - moved parameters for flowcover and cmir separators to `separating/aggregation`
3166- Removed parameters:
3167 - `constraints/{abspower,bivariate,nonlinear,quadratic,soc}/scaling`
3168 - `constraints/{abspower,bivariate,quadratic,nonlinear}/mincutefficacysepa`
3169 - `constraints/{abspower,bivariate,quadratic,nonlinear}/mincutefficacyenfofac`
3170 - `constraints/soc/minefficacy`
3172 - `conflict/prefermir`
3173 - `heuristics/clique/{multiplier,initseed}`
3174 - `separating/feastolfac`
3175 - `separating/orthofac`
3176 - `separating/cgmip/allowlocal` (use parameter passed to separation callback instead)
3177 - `separating/{gomory,strongcg}/maxweightrange`
3181- `conflict/prefinfproof` (prefer infeasibility proof to boundexceeding proof)
3182- `conflict/sepaaltproofs`
3183- `constraints/indicator/maxsepanonviolated` to stop separation after separation of non violated cuts
3184- `constraints/orbisack/coverseparation` (whether orbisack cover inequalities should be separated)
3185- `constraints/orbisack/orbiSeparation` (whether facet defining inequalities for orbisack should be separated)
3186- `constraints/orbisack/coeffbound` (maximal value of coefficients in orbisack facet inequalities)
3187- `constraints/orbisack/checkpporbisack` (check whether orbisacks can be strengthened by packing/partitioning constraints)
3188- `constraints/orbisack/checkalwaysfeas` (whether conscheck returns always `SCIP_FEASIBLE`)
3189- `constraints/orbitope/checkpporbitope` (check packing/partitioning orbitopes)
3190- `constraints/orbitope/sepafullorbitope` (separate full orbitopes)
3191- `constraints/orbitope/checkalwaysfeas` (whether conscheck returns always `SCIP_FEASIBLE`)
3192- `constraints/quadratic/{usebilinineqbranch,minscorebilinterms,bilinineqmaxseparounds}`
3193- `constraints/quadratic/disaggrmergemethod` to change the strategy of how to merge independent blocks of quadratic constraints
3194- `constraints/quadratic/mincurvcollectbilinterms` to change the minimal curvature of constraints
3195 to be considered when returning bilinear terms to other plugins
3196- `constraints/quadratic/binreformbinaryonly` to disable reformulation of products of binary and non-binary variables
3197- `constraints/symresack/ppsymresack` (check whether symresacks can be strengthend by packing/partitining constraints)
3198- `constraints/symresack/checkalwaysfeas` (whether conscheck returns always `SCIP_FEASIBLE`)
3199- `expbackoff` to all separators which increases the frequency exponentially over the depth in the tree
3200- `heuristics/completesol/{beforepresol,maxlpiter,maxcontvars}`
3201- `heuristics/{clique,vbounds}/maxbacktracks` to limit the number of backtracks in the fix-and-propagate phase
3202- `heuristics/{clique,vbounds}/uselockfixings` to enable fixing of additional variables based on variable locks
3203- `heuristics/vbounds/{feasvariant,tightenvariant}` to specify the fixing variants used by the vbounds heuristic
3204- `lp/refactorinterval` to change the refactorization interval of the LP solver
3205- `misc/debugsol` to specify a debug solution that should be checked during the solve
3206- `misc/usesymmetry` to determine whether symmetry handling should be used
3207- `presolving/symbreak/conssaddlp` (whether symmetry handling inequalities should be added to the LP)
3208- `presolving/symbreak/addsymresacks` (whether symresacks should be used to handle symmetries)
3209- `presolving/symbreak/computeorbits` (whether symmetry orbits should be computed)
3210- `presolving/symbreak/detectorbitopes` (whether it should be checked if some symmetries can be handled by orbitopes)
3211- `presolving/symmetry/computepresolved` (Whether symmetries are computed after presolving)
3212- `presolving/symmetry/maxgenerators` (maximal number of generators generated by symmetry detection)
3213- `presolving/symmetry/checksymmetries` (whether validity of computed symmetries should be verified)
3214- `propagating/obbt/{itlimitfactorbilin,minnonconvexity,createbilinineqs}`
3215- `propagating/vbounds/minnewcliques` to specify the minimum number of new cliques to trigger another clique table analysis
3216- `propagating/vbounds/{maxcliquesmedium,maxcliquesexhaustive}` to limit the number of cliques relative to the
3217 number of binary variable for performing clique table analysis
3218- `separating/maxincrounds`
3219- `separating/maxlocalbounddist`, `separating/maxcoefratio` and `separating/intsupportfac`
3220- if PaPILO >= 2.1: `presolving/milp/maxbadgesizepar` to limit the maximal badge size if PaPILO is called in parallel mode
3221- if PaPILO >= 2.1: `presolving/milp/maxbadgesizeseq` to limit the maximal badge size if PaPILO is called in sequential mode
3225- new type `SCIP_Shortbool` (equal to uint8_t) for storing Boolean values in a more compact manner
3226- new disjoint set data structure `SCIP_DISJOINTSET` to incrementally update connectedness information for a graph on nodes {0,...,n-1}
3227- new red black tree data structure defined in `src/scip/rbtree.{c,h}`
3228- new object `SCIP_LINCONSSTATS`, see type_cons.h, to work with linear constraint classification through the C API
3229- added new type `SCIP_TABLE` together with callbacks to output SCIP statistics
3234- added several tests for the LP interface
3235- added tests that cover nonempty linear constraint classification types
3236- added tests for the double double arithmetic, the new red black tree data structure, the nlpi, obbt, interval arithmetics,
3237 symmetry computation, objective function changes in probing, computing envelopes of bilinear function, relaxation enforcement
3242- added interface to the NLP solver WORHP; set `WORHP=true` in order to link to WORHP
3243- added interface to the NLP solver FilterSQP; set `FILTERSQP=true` in order to link to FilterSQP
3247- added support for sanitizers in debug mode and options SANITIZE_ADDRESS, SANITIZE_MEMORY, SANITIZE_UNDEFINED, SANITIZE_THREAD
3248- added option SYM to specify which graph automorphism package (bliss, none) should be used, if available
3249- disable non-standard compliant floating point optimizations in combination with intel compilers
3250- improve Visual Studio compilation
3251- only accept IPOPT version 3.12.0 or higher
3252- preserve correct rpath in library (e.g. path to libipopt) when installing
3256- new flag `DEBUGSOL={true,false}` to enable checks against a user given debug solution
3257- added flag SYM to specify which graph automorphism package (bliss, none) should be used
3258- default value for ZIMPL in the Makefile is now `false`
3263- fix wrong statistic display of diving leaf solutions
3264- fixed order of SCIPcalcCliquePartition() in corner case where no cliques are available
3265- fix treatment of infinite lower bound in proximity objective cutoff
3266- fixed minor issue in expression graph simplification
3269 - fix linear knapsack relaxation during separation if a binary variable does not have a solution value in [0,1].
3270 - fixed potential ressource leaks in SCIPsolveLinearProb(), expr.c, sepa_eccuts, cons_cumulative.c, cons_nonlinear.c
3271 - fixed bug in cons_orbitope.c, where wrong terminating index in separation of SCIs was used
3272 - fixed wrong mapping of permuted basis indices in gomory separator
3273 - fixed integer objective separator for objective scales < 1
3276 - fixed numerical issues in boundshift presolver when aggregating integer variables
3277 - fixed aggregation of variables in boundshift presolver that contain large variable bounds
3280 - fixed bug in feasibility pump heuristic when switching on the `usefp20` parameter
3281 - fixed handling of LOOSE variables in locks heuristic
3282 - fixed creation of conflicts in clique heuristic for incomplete LPs
3285 - fixed bug in mps reader. Reader now prints `OBJSENSE` section and tries to generate unique names of constraints
3286 - fixed upgrade to a varbound constraint if abspower constraint contains a multi-aggregated variable
3287 - fixed several bugs related to hashing of constraints/rows in cutpool.c and cons_linear.c
3288 - fixed registration of almost fixed nonlinear variables in abspower constraints
3291 - fixed releasing of variables in the genvbounds propagator in case the problem could be solved during presolving of a restart
3292 - fixed numerical issues in bound widening of variable bound constraint handler and vbound propagator during conflict analysis
3294@page RN4 Release notes for SCIP 4
3296@section RN401 SCIP 4.0.1
3297*************************
3302- added parsing functionality to cardinality constraint handler for CIP format
3303- allow to relax objective limit in reoptimization in presolved stage
3304- suppress excessive printing about numerical troubles in LP on default verblevel (high)
3306Performance improvements
3307------------------------
3309- only accept passed improving solutions in heur_indicator
3310- add and use RESTRICT macro for some pointers
3311- sorting of parents and children for some expression types is now independent of memory layout
3314 - widened a bottleneck in simplifying long signomial sums in a nonlinear constraint
3315 - unified and extended code that improves numerics of cuts generated by nonlinear constraint handlers
3318 - stop separation in cons_indicator after maxsepanonviolated many non violated separated cuts
3319 - improve choice of variable to enter support in separation of cons_indicator
3324### New API functions
3326- SCIPvalidateSolve() to compare solving result with an external primal and dual reference value
3327- SCIPisObjChangedProbing() to check whether the objective function has changed during probing mode
3328- SCIPgetDualSolVal() to get the dual solution value of a constraint
3329- SCIPisLPPrimalReliable() and SCIPisLPDualReliable() to check whether the current primal / dual LP solution
3330 were successfully checked for feasibility
3332### Command line interface
3334- New option in the interactive shell to validate the solution against an external primal and dual reference value
3335- added command line option `-o` and command `validatesolve` in interactive shell
3336 to validate the solution against an external primal and dual reference value.
3338### Interfaces to external software
3340- Updated and new interfaces to Mosek 8.1, GAMS and Gurobi
3341- new LP interface to Glop (Google OR tools); CMake only
3343### Changed parameters
3345- renamed parameter `heuristics/completesol/maxunkownrate` to `heuristics/completesol/maxunknownrate`
3350- add options to make test target (see Makefile section)
3357- New CMake build system alongside the usual Makefile setup
3361- added make options for specifying EXECUTABLE and OUTPUTDIR variables for the make test target
3366- fixed unintended behavior of interrupt signal handler inside SCIP copies
3367- fixed uninitialized values in SCIP's digraph data structure after calling SCIPdigraphResize()
3368- fixed issue related to SCIPcreateFiniteSolCopy() not being able to remove all infinite fixings
3369- fixed issue in SCIPcopyLimits() w.r.t. soft time limit
3370- fixed bug in dynamic resizing of hashtables and hashmaps
3371- added workaround for bug in primal simplex of cplex 12.7.1.0 occuring when attempting to solve LPs without rows without presolving
3372- fixed bug in binpacking example that might have led to doing the same branching several times
3373- fixed memory issue in binpacking example
3374- in GAMS writer, forbid also various parenthesis characters in gams symbol names
3375- added missing definition of `SCIP_UNUSED` in memory.h if def.h is not included
3376- treat reopt bugs: Avoid numerical problems with changing objective; fix check for changed objective
3377- fixed reading issue in mps reader: integer variables fixed to 0 or 1 are treated as binaries now,
3378 allowing to use them as indicator variables
3379- afternode heuristics are now called even if the node limit was reached and the solving process will be stopped
3380 after the current node
3381- fixed bug when activating probing mode with a non-empty separation storage
3384 - fixed guard against using old Gurobi versions in lpi_grb.c: Gurobi 7.5 was not permitted
3385 - fixed wrong handling of unboundedness status in lpi_grb.c
3386 - fixed wrong handling of row basis status in lpi_grb.c
3389 - fixed bug in shift and propagate--variable information with a negation transformation is correctly reset after backtracking
3390 - fixed bug in genvbounds propagator when applying a restart after the root node
3393 - fixed bug in varbound coefficient tightening: if a varbound constraint only contained one variable afterwards,
3394 it may have been deleted without applying the induced bound, if the change was too small, this is now forced
3395 - fixed potential wrong locks update after a varbound constraint became redundant in coefficient tightening
3396 - fixed potentially wrong cleanup of fixed variables in nonlinear constraint handler
3397 - fixed memory leak in OSiL reader when using SOS constraints
3400 - improved handling of infinite values in a primal solution in quadratic and nonlinear constraints
3401 - fixed bug in computing violation and cut for certain nonlinear constraints when LP solution is slightly out of bounds
3402 - fixed debug solution check that appeared in probing mode when the objective function has changed
3403 - relaxed a too strong assert concerning solutions close to the objective limit
3405@section RN400 SCIP 4.0.0
3406*************************
3411- Introduced support for partial or infeasible user solutions, which SCIP tries to complete/repair heuristically
3412- implemented linear time methods for (weighted) median selection for joint arrays of various types
3413- added adaptive solving behavior of SCIP based on solving phases and heuristic transitions, if enabled via `solvingphases/enabled`
3414- can now solve relaxations within probing
3415- in case of multiple relaxators the best solution is saved instead of the last one
3416- added write callback for reader_bnd
3417- added possibility to use a reference value for advanced analysis of the tree search. If a finite reference value
3418 (an objective value in original objective space) is passed via misc/referencevalue, SCIP keeps track of the
3419 number of nodes exceeding the reference value and the number of early backtracks -- path switches in the tree when
3420 a child node with lower bound smaller than the reference value was available.
3421- added reading capabilities for partial solutions with extension *.mst
3422- new global shift off all random seeds (randomization/randomseedshift) and unification of all existing random seeds
3423- use new macros SCIPdebugMsg(), SCIPsetDebugMsg(), SCIPstatDebugMsg() at all places where it makes sense
3424- new random number generator in pub_misc.h
3425- add check whether variables have been released when freeing SCIP
3426- a print callback can now be specified for user expressions
3429 - will now enforce relaxation solution instead of lp or pseudosolution if lowerbound is better and the whole lp is included in the relaxation
3430 - new feature solution polishing to improve integrality of LP solutions
3433 - new constraint handler for cardinality constraints
3434 - added interval-evaluation of sine and cosine
3435 - allow to create constraints of constraint handlers that don't need constraints
3436 - New constraint handlers cardinality and components
3439 - implement a storage for conflicts to have more control over active conflicts
3440 - Improved conflict analysis through central conflict pool and dual ray analysis for primal infeasible LPs; can now analyze dual
3441 unbounded rays of primal infeasible LPs
3444 - New presolvers that disaggregate SOC constraints and reformulate QP's by adding KKT conditions
3445 - new presolving step for variables contained in a single quadratic constraint with proper square coefficients
3446 - add new presolving step to disaggregate second order cone constraints
3447 - new presolving method presol_qpkktref to add the KKT conditions of a QP
3448 - implemented and extended stuffing presolving in linear constraint handler
3449 - new components constraint handler which replaces the components presolver; it searches for independent subproblems
3450 and solves small ones as sub-SCIPs during presolve, larger ones are solved alternatingly during the main solving process
3451 - new presolving timing FINAL: presolving methods with this timing are only called once after all other presolvers with timings
3452 FAST, MEDIUM and EXHAUSTIVE are finished; during this timing only reductions are allowed that are self-contained, e.g.,
3453 fixing all variables and deleting all constraints of an independent component; note that reductions found in this timing
3454 do not trigger a new presolving round
3456- Separation and Cuts:
3457 - can now separate perspective cuts for indicator constraints
3458 - add sepa_convexproj, a separator which projects onto convex relaxation and build gradient cuts at the projection
3459 - add sepa_gauge, a separator which computes an interior point of a convex relaxation and performs a binary search in the segment joining
3460 the interior point and the point to separate until it finds a point in the boundary of the feasible region where to build a gradient cut
3461 - changed handling of coupling constraints in cons_indicator; the cuts will not be added to the pool, but are separated by default
3462 - concurrent solving mode that allows to run multiple SCIP instances, that share solutions and global variable bounds, in parallel
3463 - Revised pseudo random number generation and introduced central random seed for all plugins
3466 - new Graph induced neighborhood search (GINS) primal heuristic that uses neighborhoods
3467 based on distances in the variable constraint connectivity graph.
3468 In addition, the heuristic supports a rolling horizon-like procedure to solve auxiliary problems
3469 for neighborhoods with increasing distance from the starting neighborhood.
3470 - new primal heuristic LP face that tries to find an integer solution inside the optimal LP face.
3471 - new heuristic that tries to complete partial solutions
3472 - the subnlp heuristic now gives ownership of a found solution to the heuristic that constructed the starting point, if any;
3473 as a consequence, MIP heuristics may now be shown more frequently for having found a solution when solving MINLPs, even
3474 though the solutions required an additional NLP solve
3475 - new multistart heuristic for NLPs
3478 - add prop_nlobbt, a nonlinear optimization-based bound propagator solving two convex NLP relaxations for each variable
3479 - nodes can now be postponed; currently, this can only be triggered by BEFORELP propagation callbacks
3482 + Extended statistic output displayable via the interactive shell
3483 + new statistic computed: `Root LP Estimate` that shows the root LP best-estimate with every pseudo-cost update
3484 + added leaf statistics about LP objective limit|feasible|infeasible leaves to the statistics output and
3485 to the callable library: SCIPgetNObjlimLeaves(), SCIPgetNFeasibleLeaves(), SCIPgetNInfeasibleLeaves()
3486 + next to the number of found solution, also the number of new best solutions is now printed for each heuristic
3487 (and relaxation solutions) in the statistics in the `Primal Heuristic` section.
3489Performance improvements
3490------------------------
3492- Extended the presolving timings by an additional timing FINAL for self-contained reductions
3493- Randomized tie-breaking in different parts of the code to reduce performance variability
3494- use connectedness information of the clique table to speed up the clique partitioning algorithm
3495- knapsack approximation algorithms use linear-time weighted median selection instead of sorting
3496- improved greedy solution in SCIPsolveKnapsackApproximatelyLT() for the flow cover separation
3497- reduce performance variability by using random numbers as tie-breaker for external branching candidates
3500 - adjusted most Large Neighborhood Search heuristics such that they collect their variable fixings first in an array,
3501 and only create and populate a sub-SCIP if enough variables will be fixed.
3502 - reduce performance variability by using a small perturbation in the undercover heuristic
3503 - 1-opt heuristic can now be repeatedly executed as long as new incumbents are found
3506 - Improved and extended stuffing inside of linear constraint handler
3507 - Changed handling of coupling constraints in cons_indicator
3508 - SCIP supports constraint compression for problem copies; constraint compression denotes the immediate
3509 removal of fixed variables from constraint data at creation time to reduce memory requirements.
3512 - rewrote the propagate-and-cut-and-price loop so that successful propagations with DURINGLPLOOP timing, bound changes found by separation,
3513 and new primal solutions now trigger a new round of node solving, starting with propagation; improved tuning of propagation and heuristic timings
3514 - tuned propagation methods of several constraint handlers
3515 - make more use of SCIPmarkConsPropagate() to mark constraints for propagation and improved the internal handling of marked constraints
3516 - improve propagation of absolute-value expression in the case that the sign of the argument is fixed
3521### New and changed callbacks
3524 - extended interface to support concurrent solving mode
3526- Constraint Handlers:
3527 - new optional callback `CONSENFORELAX` to enforce a relaxation solution, see \ref CONS
3528 - `CONSINITLP` callback now has a new parameter `infeasible`, which is a pointer to store whether infeasibility
3529 was detected while building the initial LP relaxation
3531### Deleted and changed API methods
3533- setting a parameter to a non-valid value now produces an error message instead of a warning
3534- bound reader uses angle bracket around variable names
3535- the parameters of SCIPlpiChgObj(), SCIPlpiSetBase(), SCIPlpiSetState(), SCIPlpiSetNorms() have been declared as const
3536- SCIPapplyHeurSubNlp() can now return the solution found by the sub-NLP heuristic
3539 - methods SCIPrandomGetInt() substitutes SCIPgetRandomInt() (marked to be deprecated)
3540 - methods SCIPrandomGetReal() substitutes SCIPgetRandomReal() (marked to be deprecated)
3541 - methods SCIPrandomPermuteArray() substitutes SCIPpermuteRandomArray() (marked to be deprecated)
3542 - methods SCIPrandomPermuteIntArray() substitutes SCIPpermuteRandomIntArray() (marked to be deprecated)
3543 - method SCIPrandomGetSubset() substitutes SCIPgetRandomSubset() (marked to be deprecated)
3546 - added parameters `conftype` and `iscutoffinvolved` to SCIPinitConflictAnalysis()
3547 that indicate the type of the conflict and whether the current cutoff bound is used or not
3549- Constraint Handlers:
3550 - added parameter `infeasible` to SCIPinitlpCons()
3553 - added parameters `fixedvars`, `fixedvals`, `nfixedvars` to SCIPcopyVars()
3554 - added parameters `fixedvars`, `fixedvals`, `nfixedvars` to SCIPcopyOrigVars()
3555 - renamed parameter `success` to `valid` in SCIPgetConsCopy()
3557- Hashmap and Hashtable:
3558 - removed function SCIPcalcHashtableSize() since not required anymore for `SCIP_HASHTABLE` and `SCIP_HASHMAP`
3559 - based on the initial size `SCIP_HASHTABLE` and `SCIP_HASHMAP` choose an appropriate size internally to allow insertion of that
3560 many elements without resizing
3561 - `SCIP_MULTIHASH` behaves like the old `SCIP_HASHTABLE` and SCIPcalcMultihashSize() should be used as replacement for
3562 SCIPcalcHashtableSize()
3564- Nonlinear Relaxation:
3565 - added parameter `curvature` to SCIPcreateNlRow()
3568 - the following new methods return a bool indicating whether the given value is valid for the parameter instead of printing a warning
3569 message and returning an error code if the value is invalid
3570 - renamed method SCIPcheckBoolParam() to SCIPisBoolParamValid()
3571 - renamed method SCIPcheckLongintParam() to SCIPisLongintParamValid()
3572 - renamed method SCIPcheckCharParam() to SCIPisCharParamValid()
3573 - renamed method SCIPcheckStringParam() to SCIPisStringParamValid()
3574 - renamed method SCIPcheckRealParam() to SCIPisRealParamValid()
3575 - in param.c/h: the new methods return a bool whether the given value is valid for the parameter instead of printing a warning message
3576 and returning an error code if the value is invalid
3577 - rename SCIPparamCheckBool() to SCIPparamIsValidBool()
3578 - rename SCIPparamCheckString() to SCIPparamIsValidString()
3579 - rename SCIPparamCheckChar() to SCIPparamIsValidChar()
3580 - rename SCIPparamCheckLongint() to SCIPparamIsValidLongint()
3583 - added parameter `initialseed` to SCIPcreateDiveset()
3584 - introduced new type `SCIP_HEURTIMING` for primal heuristic timing masks
3585 - changed type of parameter `timingmask` from unsigned int to `SCIP_HEURTIMING` in SCIPincludeHeur(), SCIPincludeHeurBasic()
3588 - new parameter `includeslp` for SCIPincludeRelax() and SCIPincludeRelaxBasic()
3589 to indicate whether relaxation includes all linear rows and can be enforced
3592 - rename method SCIPgetReopSolsRun() to SCIPgetReoptSolsRun()
3595 - added parameter `completely` to SCIPtrySol(), SCIPtrySolFree(), SCIPcheckSol() to check all constraints when
3599 - removed SCIPvarGetLbAtIndex() and added SCIPgetVarLbAtIndex()
3600 - removed SCIPvarGetUbAtIndex() and added SCIPgetVarUbAtIndex()
3601 - removed SCIPVarGetBdAtIndex() and added SCIPgetVarBdAtIndex()
3602 - removed SCIPvarWasFixedAtIndex() and added SCIPgetVarWasFixedAtIndex()
3603 - Removed method SCIPvarGetNBinImpls()
3605### New API functions
3607- added functions for concurrent solving mode (see concurrent.h, concsolver.h)
3608- SCIPcreateNlpiProb(), SCIPupdateNlpiProb() and SCIPaddNlpiProbRows() to create and update a nonlinear relaxation
3609- SCIPgetNObjlimLeaves(), SCIPgetNFeasibleLeaves(), SCIPgetNInfeasibleLeaves() for statistics output
3610 about LP objective leaves
3611- SCIPcheckCopyLimits() which can be used to check that enough time and memory is left to run a sub-SCIP after
3612 subtracting time and memory used by the main-SCIP and SCIPcopyLimits() which copies these limits accordingly and disables
3613 all other limits (need to be set by the plugin, if needed)
3614- SCIPcopyLargeNeighborhoodSearch() in heuristics.h that supports compressed copying and two kinds of problem copy: the MIP-relaxation or
3615 a 1-1 problem copy (by copying the constraints and not the LP relaxation)
3616- SCIPsolveProbingRelax() to solve a relaxation within probing
3617- SCIPgetLastStrongbranchingLPSolstat() to query the LP statuses after strong branching on a variable
3618- SCIPinitializeRandomSeed()
3619- SCIPswapReals() to swap two real values
3620- SCIPgetNNZs() to get the number of active non-zeros in the transformed/presolved problem
3623 - SCIPprintDebugMessage(), SCIPsetPrintDebugMessage(), SCIPstatPrintDebugMessage() that output debug messages and also print the
3624 subscip depth; the first two output via the message handler; also added macros SCIPdebugMsg(), SCIPsetDebugMsg(), SCIPstatDebugMsg()
3625 - SCIPdebugMsgPrint()/SCIPsetDebugMsgPrint() that output a message without `[debug]` prefix via the message handler (compare SCIPdebugPrintf())
3628 - SCIPisDualSolAvailable() to query the dual solution availability
3629 - SCIPlpiSetIntegralityInformation() to improve SoPlex' solution polishing
3632 - library methods SCIPcopyConsCompression(), SCIPcopyOrigConsCompression() that accept an array of variables that are immediately
3633 fixed in the copy. Alternatively, local instead of global bounds can be used for compression.
3634 - library methods SCIPenableConsCompression(), SCIPisConsCompressionEnabled(), SCIPcopyConsCompression(), SCIPcopyOrigConsCompression()
3635 - SCIPgetIntVarXor() to access integer variable of XOR constraints
3636 - SCIPcreateConsCardinality() to create a cardinality constraint
3637 - SCIPcreateConsBasicCardinality() to create a basic cardinality constraint
3638 - SCIPchgCardvalCardinality() to changes cardinality value of cardinality constraint (i.e., right hand side of cardinality constraint)
3639 - SCIPaddVarCardinality() to add a variable to a cardinality constraint
3640 - SCIPappendVarCardinality() to append a variable to a cardinality constraint
3641 - SCIPgetNVarsCardinality() to get the number of variables in a cardinality constraint
3642 - SCIPgetVarsCardinality() to get the array of variables in a cardinality constraint
3643 - SCIPgetCardvalCardinality() to get the cardinality value of a cardinality constraint (i.e., right hand side of cardinality constraint)
3644 - SCIPgetWeightsCardinality() to get the array of weights of a cardinality constraint
3645 - SCIPgetLinvarMay{Decrease,Increase}Quadratic() to get index of a variable in linear term of quadratic constraint that may be decreased
3646 without making any other constraint infeasible
3649 - add SCIPparamIsValidInt() and SCIPparamIsValidReal() to param.c/h
3650 - add missing functions SCIPisIntParamValid() and SCIPisRealParamValid() to scip.c/h
3652### Command line interface
3654- new command line parameter `-v` to print detailed build options
3656### Interfaces to external software
3658- Interfaces for Python and Java are, among others, now available via http://www.github.com/scip-interfaces
3659- Revised documentation of the SCIP C-API to group methods more comprehensively by topics
3660- dropped support for Ipopt < 3.11
3661- Additional I/O-functionalities for debugging and logging in SCIP and in the AMPL interface
3662- updated CppAD to 20160000
3663- for users of the ampl interface, the display/logfile option has been added to set the name of a
3664 file to write the SCIP log to (additionally to stdout)
3667 - SCIP uses the lpi_spx2 interface by default
3668 - Improved Gurobi interface that can handle ranged rows (requires Gurobi >= 7.0.2)
3669 - the CPLEX LPI now also compiles with CPLEX 12.7.0.0
3671### Changed parameters
3673- setting a value for a fixed parameter will no longer return with an error, if the new value equals the one to which the parameter is fixed
3674- changed value of parameter `separating/clique/cliquedensity` to 0.0 such that the separator always constructs a dense clique table
3675 which proved to be faster on the benchmarks MMM and stableset.
3676- parameters `misc/permutationseed`, `misc/permuteconss` and `misc/permutevars` changed to `randomization/permutationseed`,
3677 `randomization/permuteconss` and `randomization/permutevars`
3678- parameters `conflict/useinflp` and `conflict/useboundlp` are now of type char (before bool)
3679- all parameters of the components presolver (starting with `presolving/components/`) are now parameters of the components
3680 constraint handler (starting with `constraints/components/`)
3684- class randomization
3685- `branching/sumadjustweight` to adjust branching scores by adding a sum epsilon in order to keep score differences
3686 near zero, which are otherwise completely disregarded (they are adjusted to at least sum epsilon)
3687- `concurrent/∗ ` and `parallel/∗ ` for configuring the concurrent solving mode
3688- `constraints/cardinality/branchbalanced` to decide whether to use a balanced branching scheme in the enforcing of cardinality
3690- `constraints/cardinality/balanceddepth` to set the maximal depth until balanced branching is turned off
3691- `constraints/cardinality/balancedcutoff` to determine that balanced branching is only used if the branching cut off value
3692 w.r.t. the current LP solution is greater than a given value
3693- `constraints/indicator/sepaperspective` to turn on separation of perspective cuts for indicator constraints
3694- `constraints/indicator/sepapersplocal` to decide whether local cuts can be used for perspective cuts for indicator constraints
3695- `constraints/quadratic/projectedcuts` to enable convex quadratics to generate gradients cuts at the
3696 projection of the point onto the region described by the constraint, which is supporting
3697- `lp/solutionpolishing` to enable LP polishing only at the root LP or always
3698- `misc/referencevalue` to pass a reference value for further analysis of the tree search, see also in `features`
3699- `presolving/qpkktref/addkktbinary` to allow the presence of binary variables for the KKT update
3700- `presolving/qpkktref/updatequadbounded` to add the KKT conditions to QPs only if all variables are bounded
3701- `presolving/qpkktref/updatequadindef` to add the KKT conditions to QPs only if the quadratic matrix is indefinite
3702- `randomization/lpseed` to set the initial seed of the LP solver
3703- `solvingphases/enabled` to activate adaptive behavior during the solution process; several further parameters
3704 in the solvingphases-section to control how to switch the parameters and whether a restart should be performed between the phases.
3708- new `SCIP_REGRESSION` data structure in pub_misc.h to incrementally compute a best-fit line through pairs of observations
3709- add maximum branch-and-bound tree depth constant `SCIP_MAXTREEDEPTH` (replaces SCIPgetDepthLimit() and SCIPtreeGetDepthLimit())
3710- new files heuristics.c/heuristics.h to collect methods that are frequently used by heuristics
3711- merged dive.c/pub_dive.h with heuristics.c/heuristics.h, removed dive.c/pub_dive.h
3712- separated header pub_misc.h from repeated methods for sorting and (weighted) median selection;
3713 those are also available in separate headers pub_misc_sort.h
3714 and pub_misc_select.h, but included into pub_misc.h
3719- New unit testing system built on the Criterion framework
3726- All makefiles in `examples/` and `applications/` have been updated.
3727- `make.project` defines a variable `SCIP_VERSION` containing the SCIP version number
3728- revise sub-makefiles for MSVC on MinGW
3729- make shared libraries aware of their dependencies
3730- sub-makefile for CrayXC systems added
3733 - All objective files are now placed in `obj/static` or `obj/shared`, depending on `SHARED=false` or `SHARED=true`, respectively.
3734 - All internal and external libraries are placed in `lib/static` and `lib/shared`, the include files are in `lib/include`.
3735 - The binaries now contain an rpath to the SCIP directory, such that shared libraries are found.
3738 - link binary to shared libs when compiling with `SHARED=true`
3739 - External projects (including make.project) can use the makefile variable LINKCXXSCIPALL or LINKCCSCIPALL to link all SCIP libraries.
3740 - Building with `SHARED=true` automatically generates the combined library libscipsolver.so for easier linking
3743 - Running `make help` lists all makefile options.
3744 - `make install` copies now all header files
3745 - new target `dll` to build Windows dlls with MSVC
3746 - rename `dll` target to `windowslib`
3751- fixed bug in event system: bound change events of the new focus node must be processed, even if the bound
3752 is the same as at the last focus node
3753- avoid numerically unstable (multi-)aggregations
3754- fixed bug in XML reader concerning comments
3755- the AMPL interface now writes a solve status (solve_result_num) into the .sol file
3756- in the cmpres.awk (allcmpres.sh) output, the counts in the time column are now with respect to the
3757 whole set of processed instances (as with fail and solv), while before it was with respect to the
3758 set of instances where no solver failed (eval set); thus, now proc = fail + time + solv.
3759- writing of solutions or parameters to a file now works also with the message handler set to quiet
3760- ignore lower and upper bound tightenigs beyond +/-infinity during solving
3761- time limit of SCIP-infinity is converted to LPI-infinity when setting it
3762- fix LP activity of a row that has been modified
3765 - fixed possible segmentation fault in genvbounds propagator
3766 - fixed bug with sorting of propagators in presolving: the order can be changed by calling probing; thus, there is a copy of the
3767 propagators, which is sorted by presolving priority
3768 - added missing capturing and releasing mechanism in genvbounds propagator
3769 - fix wrong propagation of product expressions
3772 - fixed wrong representation of SOC constraints in NLP
3773 - fixed a few issues within redundant constraint detection of (specialized) linear constraint handlers
3774 - fixed issue in reader_opb concerning writing of fixed variables contained in no constraints
3777 - fixed memory bug in `SCIP_DIGRAPH`
3778 - improved counting of memory consumption by using more block memory and counting all allocated memory
3779 - fix memory leaks in TSP example
3780 - return `SCIP_ERROR` when a memory exception is caught in SoPlex (was `SCIP_LPERROR`)
3781 - fixed memory leak in OSiL reader
3784 - fixed bug while changing the objective value of an original value after transforming the problem
3785 - fixed bug with solutions from previous runs not satisfying an objective limit
3786 - SCIPisObjIntegral() now works correctly in `SCIP_STAGE_PROBLEM`
3789 - fixed two bugs in heur_indicator: use improvesols parameter now and update pointer to indicator constraint handler
3790 - fix wrong NLP representation of logic-or constraints in the dual value heuristic
3791 - correct handling of implicit integer variables with fractional solution value in simplerounding heuristic
3792 - fixed bug in heur_octane with uninitialized ray direction
3794@page RN3_2 Release notes for SCIP 3.2
3796@section RN321 SCIP 3.2.1
3797*************************
3802- new `force` parameter in (root)redcost propagator to run the propagator also with active pricers
3804Performance improvements
3805------------------------
3807- do not transfer solutions to original space, if SCIP is being freed
3808- modified implication graph analysis of SOS1 constraint handler; a new component allows to deduce zero fixings of variables
3809- made SOS1 constraint handler specific diving selection rule faster for the case that the SOS1 constraints do not overlap
3810- improved disjunctive cuts by the `monoidal cut strengthening` procedure of Balas and Jeroslow
3812Examples and applications
3813-------------------------
3815- several improvements of SCIP-Jack (STP application): extended presolving for STP variants, STP-specific branching
3816 rule, dual heuristic to generate initial LP relaxation
3817 SCIP-Jack is now competitive with problem specific state-of-the-art solvers on several well-known STP variants,
3818 e.g., the (rooted) prize-collecting Steiner tree problem.
3819- MultiObjective application renamed to PolySCIP; several improvements: better command line argument processing,
3820 overhaul of much of the source code, installation via CMake
3825- made debug solution functionality thread safe (see debug.h for further information)
3827### Deleted and changed API methods
3829- add SCIPcomputeHyperplaneThreePoints() to compute a hyperplane containing three given 3-dimensional points
3830- SCIPsolveLinearProb() now uses a 1-dimensional matrix representation
3832### Command line interface
3834- added interactive shell command `display finitesolution` to print solution with infinite fixings removed,
3835 added reference to that method to `display solution` output if there are infinite fixings
3836- new interactive shell command `write history` to write the command line history (only when compiled with Readline)
3838### Interfaces to external software
3840- significantly improved Python interface to support user callbacks as well as linear and quadratic expressions
3844- `constraints/sos1/branchingrule` to decide whether to use neighborhood, bipartite, or SOS1 branching (this parameter
3845 replaces the old parameters `constraints/sos1/neighbranch`, `constraints/sos1/bipbranch`, and `constraints/sos1/sos1branch`)
3846- `constraints/sos1/depthimplanalysis` to limit the number of recursive calls of implication graph analysis
3847- `constraints/sos1/perfimplanalysis` to perform an implication graph analysis to deduce variable fixings and
3848 additional SOS1 constraints (this parameter replaces the old parameter `constraints/sos1/updateconflpresol`)
3849- `misc/transsolorig` for transfering transformed solutions to the original space (default: true)
3850- `propagating/rootredcost/onlybinary` to propagate root reduced costs of binary variables only
3854- renamed MIP matrix structure to `SCIP_MATRIX`
3855- changed the numeric values for `PRESOLTIMING` flags
3862- new target `dll` to build Windows dlls with MSVC
3863- add new compiling flag OPENSOURCE to allow/forbid the usage of third party software
3868- fixed wrong objective sense when copying the original problem
3869- fixed a bug in merge step of cliques during clean up phase; method did not correctly handle infeasibility in the case of multiple
3870 variable-negation pairs
3871- fixed a previously untreated case in the linear cons simplification where coefficients only differ by slightly more than an epsilon
3872- fixed bug in parsing emphasis parameters which formerly led to completely wrong results
3873- fixed bug in the computation of the Wilcoxon test
3874- do not use the relative and absolute gap limit if no primal solution has been found so far
3875- fixed bug in conflict.c with wrong reset of bounds used
3876- fixed bug with transferring solutions to new runs (need to recompute objective before checking)
3877- fixed issue with infinite values when checking cuts for redundancy
3878- fixed library problems on Windows operating systems
3881 - fixed wrong check when computing cuts for factorable quadratic functions bound tightening of a single variable
3882 - fixed wrong handling of loose variables in OBBT
3883 - fixed freeing of hash for binary variables
3884 - fixed bug during the computation of branching points for continuous variables which are almost fixed to +/- SCIPinfinity()
3885 - treated the case of integer variables as intermediate variables in the process of obtaining the active variable for a
3886 given binary variable
3889 - fixed a bug in dive.c that occurred when lpsolvefreq was set to 1; after a cutoff, the solution values of the
3890 linked LP solution might have become invalid
3891 - do not analyse an infeasible LP for conflicts during diving mode when LHS/RHS of rows were changed
3892 - use LPi infinity when reverting bound changes in conflict analysis
3895 - fixed bug in heur_simplerounding in connection with relaxators
3896 - fixed bug in feaspump heuristic where last solution candidates were not updated correctly
3897 - fixed bug with infinite shift values in heur_shifting
3898 - fixed bug in shiftandpropagate heuristic: the heuristic did not correctly handle intermediate, global bound changes of the selected variable
3899 after its tentative fixing led to a cutoff.
3902 - (root) reduced cost propagators are not run anymore when doing branch-and-price,
3903 since they may install upper bounds on variables which might interfere with the
3904 pricing (they may be enabled again by their force parameters)
3905 - fixed too hard assertion in pseudoobj propagator
3906 - fixed a bug in shiftandpropagate where column positions after sorting are now correctly linked to their variables after sorting
3907 - fixed potential memory leak in genvbound propagator
3910 - fixed inconsistency in knapsack constraint handler data during presolving
3911 - fixed some problem with reoptimization when the problems are infeasible or have been solved in presolving
3912 - fixed endless loop in knapsack constraint handler when continuous variables change their types to binary during presolving
3913 - squares of binary variables might not have been replaced by the binary variable itself in presolve,
3914 if the variable was originally general integer and only became binary during presolve (due to bound tightening)
3915 - fixed bug in dive.c avoiding a check of constraints in the presence of indicator constraints
3918 - fixed numerical problems in computation of cuts for bivariate functions in quadratic constraint handler
3919 - fixed bug in quadratic constraint handler when computing lifted-tangent inequalities
3920 - fixed bug in nonlinear constraint handler when replacing a violated nonlinear constraint leads to an infinite
3921 - fixed bug in SOS1 constraint handler with inconsistent data structure after restart
3922 - fixed wrong handling of negated variables in bound tightening procedure of SOS1 constraint handler
3923 - fixed bug in simple fixing heuristic of SOS1 constraint handler
3924 - fixed two bugs in pseudoboolean constraint handler with wrong sorting of and constraints
3925 - fixed issue: constraints being parallel to objective function (after restart) sometimes led to wrongly stating infeasible
3926 - fixed bug during coefficient tightening in varbound constraint handler
3927 - handle cutoffs in cons_indicator detected by infeasible inequalities
3928 - fixed late change of type of slack variables in cons_indicator, if the bounds are not integral
3929 - fixed initsol and exitsol of cons_indicator, if problem has already been solved
3930 - fixed bug in cons_indicator with changing type of slackvariable
3932@section RN320 SCIP 3.2.0
3933*************************
3938- added reoptimization feature for optimization problems with changed objective function or tighter feasible region
3939- the original problem can now be permuted directly after reading (if `misc/permutationseed` has value >= 0)
3940- added methods to compute strongly connected components with Tarjan's Algorithm
3941- added method to propagate implications of SOS1 variables
3942- convex quadratic contraints can now generate gradient cuts which are supporting to the feasible region
3943- SoPlex interface can now (re)store dual steepest edge weights
3944- extended expression parsing to support power, realpower and signpower operators; started support for user-defined operators
3945 in expression trees/graphs
3946- possibility to set a soft time limit which becomes active only after the first primal solution was found
3947- added matrix module for getting access to the internal mixed inter linear problem matrix
3948- better handling of large values returned by the LP solver
3949- added more checks to SCIP{alloc,realloc,duplicate}BufferArray() to handle overflows properly
3950- new plugin for reoptimizing a sequence of optimization problem that differ in the objective function, e.g., sequences arising from
3952- new plugin `compr` for rearranging the search tree, currently this only works on the reoptimization tree
3953- moved assertions in comparison methods from scip.c to set.c
3956 - we can now upgrade quadratic constraints with one bilinear term to SOC constraints
3957 - we can also upgrade general quadratic constraints with a single negative eigenvalue to SOC constraints
3960 - tighter reliability notions introduced for reliability branching, based on pseudo-cost relative errors
3961 and comparing candidates with the best pseudo-candidate using a 2-sample student-T test. These methods
3962 are used in disjunction with the existing reliability notion that uses a fixed number as reliability
3963 threshold for every variable before turning off strong-branching. This means, the classical method
3964 must be turned off by setting parameters minreliable and maxreliable to 0. The behavior is
3965 controlled through several parameters.
3966 - new distribution branching rule to base decisions on row activity (normal) distribution over domain space
3967 - can now output information for BAK: Branch-and-bound Analysis Kit
3968 - new score in hybrid reliability pseudocost branching that prefers nonlinear variables when solving MINLPs
3969 - new branching rule multaggr which allows to branch on general disjunctions defined by fractional multi-aggregated variables
3970 - new branching rules for SOS1 constraints for branching on a neighborhood or a complete bipartite subgraph of
3971 the conflict graph. In addition to variable domain fixings, it is sometimes also possible to add complementarity
3972 constraints to the branching nodes. This results in a nonstatic conflict graph, which may change dynamically
3973 with every branching node.
3974 - new branching rule nodereopt to reconstruct the tree after changing the objective function
3977 - the MPS reader can now read semi-integer variables, they are handled by creating bound disjunction constraints
3978 - the MPS reader can now handle objective constants given as (the negation of) the RHS of the objective row
3981 - obbt propagator applies now additional separation and propagation in order to learn stronger and more bound tightenings
3982 - extended probing mode to allow separation and objective coefficient changes
3983 - improved separation procedure of SOS1 constraint handler, including bound (clique) cuts and implied bound cuts
3984 - new disjunctive cut separator for SOS1 constraints
3985 - new edge-concave cut separator for quadratic constraints
3988 - Improved coordination of presolvers. There are three timings for presolvers now, FAST, MEDIUM and EXHAUSTIVE.
3989 Each presolving callback can specify one or more of these timings in which it will be called later.
3990 Within a presolving method, the current timing can be checked and the algorithms to be performed selected based on
3991 the timing. In one presolving round, first all presolving methods with timing FAST are called, sorted by priority.
3992 If they found enough reductions, a new round is started, otherwise, all presolving methods with timing MEDIUM are
3993 called. Again, with enough reductions, a new presolving round is started, too few reductions lead to running
3994 the EXHAUSTIVE presolvers. Similar to the delay concept used before, we are not neccessarily running all EXHAUSTIVE
3995 presolvers but stop as soon as one of them found enough reductions, starting a new presolving round immediately.
3996 - new presolving components for SOS1 constraints, including bound tightening and clique extension
3997 - new presolver tworowbnd for improving variable bounds and detecting redundant constraints added
3998 - new presolver dualagg for aggregating single up-/downlocked variables by a binary variable added
3999 - new presolver implfree for aggregating implied free variables added
4000 - new presolver redvub which can detect redundant variable upper bound constraints added
4001 - new presolver stuffing for fixing of singleton continuous variables added
4004 - improved clique and variable bound heuristics
4005 - new heuristic distribution diving that bases its score function on the changes regarding solution density
4006 - variable histories can be transferred between sub-SCIPs solved by LNS heuristics and the component presolver
4007 and the main SCIP to reuse this information.
4008 - new heuristic heur_indicator that tries to make partial solutions with indicator constraints feasible. It also
4009 tries to improve them (or external solutions) by a one-opt local search.
4010 - new heuristic (heur_bound) which fixes all integer variables to their lower/upper bounds and solves the remaining LP
4011 - modified diving heuristics to handle SOS1 constraints
4012 - new primal heuristic for reoptimization 'ofins': objective function induced neighborhood heuristic
4013 - new heuristic for reoptimization which constructs solutions based in the changes between the objective function and the optimal
4014 solution before changing the objective function
4017 - extended variable branching statistics in the interactive shell by sample variance of unit gains
4018 - extended statistic output of interactive shell by more information on diving heuristic behavior
4020Performance improvements
4021------------------------
4023- improved treatment of nonlinearities in hybrid reliability pseudo cost branching
4024- using sparsity information of the SoPlex LP
4027 - improved vartype upgradability from continuous to implicit variables in cons_linear.c, depending on their objective coefficients
4028 - improved propagation of SOS1 constraint handler using the information from a conflict
4031 - zi rounding heuristic uses buffer data structures, thereby decreasing total memory usage of SCIP
4032 - adjusted (hard) diving heuristics to solve fewer LPs. LP's are resolved only if a parameter-defined
4033 percentage of the variable bounds changed through domain propagation or at a predefined frequency.
4034 - some of the diving heuristics additionally consider indicator variables and SOS1 variables as candidate variables and try to
4035 make these constraint types feasible before passing a rounded solution to SCIPtrySol()
4038 - new presolving/propagation algorithm using the gcd for ranged rows and equations in cons_linear
4039 - added presolving levels (FAST, MEDIUM and EXHAUSTIVE) to allow better balancing of presolvers
4042 - improved separation procedure of SOS1 constraint handler
4043 - improved separation procedure for convex quadratic constraints
4045Examples and applications
4046-------------------------
4048- two new applications for multi-objective optimization (PolySCIP) and the Steiner Tree Problem in Graphs
4049- new application for solving Steiner tree problems: SCIP-Jack can handle both the classical Steiner tree problem in graphs
4050 and 10 of its variants
4055### New and changed callbacks
4057- new callback function `SCIP_DECL_CONSGETDIVEBDCHGS` to provide
4058 constraint handler method to suggest dive bound changes during the generic diving algorithm, see type_cons.h for details
4059- new callback `SCIP_DECL_DIVESETGETSCORE` to implement scoring function to guide diving
4061### Deleted and changed API methods
4063- avoid potential comparisons of different infinity values by adjusting the LP solution value
4064- SCIPintervalSign(), SCIPintervalAbs(), SCIPintervalMax(), SCIPintervalMin(), SCIPexprgraphGetNodePolynomialMonomialCurvature(),
4065 and SCIPexprgraphTightenNodeBounds() need an infinity value to decide whether an interval is empty or not
4066- SCIPgetFeasibilityQuadratic() and SCIPgetActivityQuadratic() returns now a `SCIP_RETCODE` and needs an additional `SCIP_Real*` to
4068- methods which support statistical tests in pub_misc.h, SCIPstudentTGetCriticalValue(), SCIPcomputeTwoSampleTTestValue() etc.
4069- SCIPsolveLinearProb() solves a linear problem of the form Ax=b for a regular square matrix A
4070- Added parameter `freesubscip` to SCIPapplyProximity()
4073 - Renamed method SCIPdigraphGetSuccessorsDatas() to SCIPdigraphGetSuccessorsData()
4074 - Renamed method SCIPdigraphGetNodeDatas() to SCIPdigraphGetNodeData()
4075 - Renamed method SCIPdigraphSetNodeDatas() to SCIPdigraphSetNodeData()
4077- Constraint Handlers:
4078 - Renamed method SCIPconshdlrGetPropTimingmask() to SCIPconshdlrGetPropTiming()
4079 - new method SCIPconshdlrSetPropTiming()
4080 - Removed method SCIPconshdlrIsPresolvingDelayed()
4081 - Removed method SCIPconshdlrWasPresolvingDelayed()
4082 - SCIPmakeSOS1sFeasible() based on solution values, fixes variables to zero to turn all SOS1 constraints feasible
4083 - removed `delay(presol)` parameter from SCIPinclude{Conshdlr,Presol,Prop}() and added `(presol)timing` parameter
4084 - new parameter `presoltiming` for method SCIPpresolCons()
4085 - SCIPvarIsSOS1() returns whether some variable is involved in an SOS1 constraint
4086 - SCIPgetConflictgraphSOS1() gets conflict graph of SOS1 constraints
4087 - Added parameter `presoltiming` to SCIPpropCumulativeCondition()
4088 - Removed parameter `delaypos` from SCIPsetConshdlrPresol()
4089 - Added parameter `presoltiming` to SCIPsetConshdlrPresol()
4090 - Removed parameter `delaypos` from SCIPincludeConshdlr()
4091 - Added parameter `presoltiming` to SCIPincludeConshdlr()
4092 - Added parameter `consgetdivebdchgs` to SCIPincludeConshdlr() to provide a divebdchg-callback for the constraint handler
4096 - Added parameter `forcestrongbranch` to SCIPselectVarStrongBranching()
4097 - Added parameter `executebranching` SCIPexecRelpscostBranching()
4098 - Added parameters `ndomredsdown` and `ndomredsup` to SCIPgetVarStrongbranchWithPropagation()
4100- LP and Cutting Planes:
4101 - Added parameters `inds` and `ninds` to SCIPgetLPBInvRow(), SCIPgetLPBInvCol(), SCIPgetLPBInvARow(), SCIPgetLPBInvACol(), and
4103 - Added parameters `maxweight`, `weightinds`, `nweightinds`, and `rowlensum` to SCIPcalcMIR()
4106 - SCIPvarGetNodeSOS1() returns node of SOS1 variable in the conflict graph
4107 - SCIPnodeGetVarSOS1() returns SOS1 variable associated to some given node in the conflict graph
4108 - Removed method SCIPvarGetNBinImpls()
4111 - Removed parameter `delaypos` from SCIPincludePresolBasic()
4112 - Added parameter `presoltiming` to SCIPincludePresolBasic()
4113 - Removed parameter `delaypos` from SCIPincludePresol()
4114 - Added parameter `presoltiming` to SCIPincludePresol()
4115 - Removed parameters `presoldelay` and `presoltiming` from SCIPincludePresol()
4116 - Removed parameters `presoldelay` and `presoltiming` from SCIPsetPropPresol()
4119 - Added parameter `isequation` to SCIPaddClique()
4120 - Removed parameter `writeimplications` from SCIPwriteCliqueGraph()
4121 - Removed method SCIPallocBufferSize()
4122 - Removed method SCIPduplicateBufferSize()
4123 - Removed method SCIPreallocBufferSize()
4124 - Removed method SCIPfreeBufferSize()
4125 - Removed method callback SCIPdialogExecConflictgraph()
4127### New API functions
4129- started support for user-defined operators in expression trees/graphs (see SCIPexprCreateUser()),
4130 interface will likely change again in future SCIP versions
4131- new methods for mixed inter linear matrix access (see pub_matrix.h) added
4132- SCIPcomputeArraysIntersection() to compute the set intersection of two ordered arrays
4133- SCIPcomputeArraysSetminus() to compute the set difference of two ordered arrays
4134- SCIPcutGetLPActivityQuot() in pub_cutpool.h to get the potion of LP's where this cut was sharp in an optimal basis.
4135- SCIPpresolGetTiming(), SCIPpresolSetTiming(), SCIP{conshdlr,prop}GetPresolTiming(), and SCIP{conshdlr,prop}SetPresolTiming()
4136- SCIPdigraphSetNSuccessors() sets the number of successors of some digraph node to a given value
4139 - SCIPcreateDiveset() to add a diveset to a heuristic. Heuristics may have multiple divesets under different names
4140 - SCIPperformGenericDivingAlgorithm() that performs diving with periodic LP resolve according to the diveset argument.
4143 - new setter function SCIPsetConshdlrGetDiveBdChgs() in scip.h to set dive bound change callback for this constraint handler
4144 - SCIPaddDiveBoundChange() to add a diving bound change to the diving bound change storage of SCIP together with the information if this is a
4145 bound change for the preferred direction or not, to be used by constraint handlers inside the getDiveBdChgs-callback
4146 - SCIPchgCoefLinear() and SCIPdelCoefLinear() to modify linear constraint during problem creation
4149 - BMSallocClearBlockMemoryArray()/SCIPallocClearBlockMemoryArray() and
4150 BMSallocClearBufferMemoryArray(), SCIPallocClearBufferArray() to allocate arrays that are initialized to 0
4151 - SCIPbuffermem() to get buffer memory;
4154 - added new sorting functions SCIPsortRealRealRealBoolBoolPtr(), SCIPsortDownRealRealRealBoolBoolPtr()
4155 - added new sorting functions SCIPsortIntIntIntReal(), SCIPsortDownIntIntIntReal(), SCIPsortRealIntInt(), SCIPsortDownRealIntInt()
4158 - SCIPwriteParam() to write a single parameter to a file
4159 - SCIPcheckParam{Bool,Char,...}() to check whether a parameter value is within the feasible domain
4162 - SCIPchgLhsQuadratic(), SCIPchgRhsQuadratic(), SCIPchgLinearCoefQuadratic(), SCIPchgSquareCoefQuadratic(),
4163 and SCIPchgBilinCoefQuadratic() to modify quadratic constraints during problem creation
4164 - SCIPgetFeasibilityQuadratic() and SCIPgetActivityQuadratic() to get the feasibility and activity of a quadratic constraint in a given solution
4165 - SCIPaddSquareLinearization(), SCIPaddSquareSecant(), SCIPaddBilinLinearization() and SCIPaddBilinMcCormick()
4166 in cons_quadratic.h to compute linear under- and overestimation for bilinear and quadratic terms
4168### Command line interface
4170- extended variable branching statistics and statistic output in the interactive shell (see Statistic section)
4171- submenu for setting `vbc` settings renamed to `visual`
4172- at the end of a command line run the best solution can now be output in the orignal space
4174### Interfaces to external software
4176- in the AMPL interface, variable and constraint attributes (flags) can now be set via suffixes, where 0 (unset) stands
4177 for the default, 1 for TRUE and other values for FALSE; see SCIPcreateVar() and SCIPcreateCons() for their meaning;
4178 for variables, `initial` and `removable` are recognized;
4179 for constraints, `initial`, `separate`, `enforce`, `check`, `propagate`, `dynamic` and `removable` are recognized
4180- the AMPL interface now passes an initial guess, if specified, as a solution (that will be checked for feasibility) to SCIP
4182### Changed parameters
4184- rowrepswitch set to 2.0, so row representation is activated if LP has at least 2 times more rows than columns
4185- one can now set emphasis parameters at the beginning of a settings file; it should start with `emphasis:` and
4186 the contain the emphasis string, e.g., `emphasis: feasibility` or `emphasis: heuristics off`.
4188- Renamed parameters:
4189 - `vbc/filename` to `visual/vbcfilename`
4190 - `vbc/realtime` to `visual/realtime`
4191 - `vbc/dispsols` to `visual/dispsols`
4195- added parameter to switch pseudo cost update in diving heuristics (enabled by default)
4196- `branching/relpscost/confidencelevel` to set the confidence level to be used by statistical tests
4197- `branching/relpscost/higherrortol` to define the highest reliability threshold for relative error based reliability
4198- `branching/relpscost/lowerrortol` to define a lower reliability threshold for relative error based reliability
4199- `branching/relpscost/nlscoreweight` for weight of nonlinear score when branching on MINLPs
4200- `branching/relpscost/usedynamicconfidence` to use a dynamic confidence level based on the amount of
4201 strong-branching simplex-iterations compared to the overall simplex iterations (default is FALSE)
4202- `branching/relpscost/usehyptestforreliability` to enable strong branching decisions based on a 2-sample student-T test of all prior
4203 pseudo-cost observations between the best pseudo-candidate and the candidate for which to decide whether strong-branching should be applied
4204- `branching/relpscost/userelerrorreliability` to enable relative error based reliability
4205- `branching/relpscost/skipbadinitcands` for skipping strong-branching candidates whose estimated gain
4206 is significantly worse than the one of the locally best (sb or pseudo) candidate
4207- `constraints/linear/multaggrremove` to perform multi-aggregations in linear constraint handler only if the constraint can be removed afterwards
4208- `constraints/linear/rangedrowpropagation` to disabled newly implemented propagtion algorithm for ranged rows and equations
4209- `constraints/quadratic/advanced/interiorcomputation` to select the way of computing and interior point for gauge cuts
4210- `constraints/quadratic/gaugecuts` to enable convex quadratics to generate gradients cuts which are supporting
4211- `constraints/soc/generalsocupgrade` to allow general quadratics to be upgraded to soc
4212- `constraints/SOS1/addcomps` to add local complementarity constraints to the branching nodes (can be used in combination
4213 with neighborhood or bipartite branching)
4214- `constraints/SOS1/addbdsfeas` to define a minimal feasibility value for local bound (clique) inequalities in order to be
4215 added to the branching node
4216- `constraints/SOS1/addcompsdepth` to define the maximal depth for adding complementarity constraints
4217- `constraints/SOS1/addcompsfeas` to define a minimal feasibility value for local complementarity constraints in order to be
4218 added to the branching node
4219- `constraints/SOS1/autocutsfromsos1` to automatically switch to separating bound cuts from SOS1 constraints if the SOS1
4220 constraints do not overlap
4221- `constraints/SOS1/autosos1branch` to switch to SOS1 branching if the SOS1 constraints do not overlap
4222- `constraints/SOS1/conflictprop` to define whether to use conflict graph propagation
4223- `constraints/SOS1/bipbranch` to branch on a complete bipartite subgraph of the conflict graph
4224- `constraints/SOS1/boundcutsdepth` to define the node depth of separating bound (clique) cuts
4225- `constraints/SOS1/boundcutsfreq` to define the frequency for separating bound (clique) cuts
4226- `constraints/SOS1/boundcutsfromgraph` to define whether to separate bound (clique) inequalities from the conflict graph
4227- `constraints/SOS1/boundcutsfromsos1` to define whether to separate bound (clique) inequalities from SOS1 constraints
4228- `constraints/SOS1/fixnonzero`: If neighborhood branching is used, then fix the branching variable (if positive in sign)
4229 to the value of the feasibility tolerance
4230- `constraints/SOS1/implcutsdepth` to define the node depth of separating implied bound cuts
4231- `constraints/SOS1/implcutsfreq` to define the frequency for separating implied bound cuts
4232- `constraints/SOS1/implprop` to define whether to use implication graph propagation
4233- `constraints/SOS1/maxaddcomps` to define the maximal number of complementarity constraints added per branching node
4234- `constraints/SOS1/maxboundcuts` to define the maximal number of bound (clique) cuts separated per branching node
4235- `constraints/SOS1/maxboundcutsroot` to define the maximal number of bound (clique) cuts separated per iteration in the root node
4236- `constraints/SOS1/maximplcuts` to define the maximal number of implied bound cuts separated per branching node
4237- `constraints/SOS1/maximplcutsroot` to define the maximal number of implied bound cuts separated per iteration in the root node
4238- `constraints/SOS1/maxextensions` to define maximal number of extensions that will be computed for each SOS1 constraint in presolving
4239- `constraints/SOS1/maxsosadjacency` to define that the adjacency matrix of the conflict graph is not created in presolving if
4240 the number of SOS1 variables is too large
4241- `constraints/SOS1/maxtightenbds` to define the maximal number of bound tightening rounds per presolving round
4242- `constraints/SOS1/neighbranch` to branch on a neighborhood of the conflict graph
4243- `constraints/SOS1/nstrongiter` to define the maximal number LP iterations to perform for each strong branching round
4244- `constraints/SOS1/nstrongrounds` to define the maximal number of strong branching rounds to perform for each node (only
4245 available for neighborhood and bipartite branching)
4246- `constraints/SOS1/sos1branch` to branch on a single SOS1 constraint, i.e., a clique of the conflict graph
4247- `constraints/SOS1/sosconsprop` to define whether to use SOS1 constraint propagation
4248- `constraints/SOS1/strthenboundcuts` to define whether to strengthen bound (clique) cuts in case bound variables are available
4249- `constraints/SOS1/updateconflpresol` to update the conflict graph during the presolving procedure
4250- `display/allviols` to print all violated constraints of the best solution during checksol in the scip shell
4251- `heuristics/indicator/improvesols` that turns on the improvement of external solutions by one-opt
4252- `heuristics/∗diving/lpresolvedomchgquot` to determine the percentage of changed domains since previous LP to trigger
4253 an LP resolve [default: 0.15] (* stands for eight diving heuristics to support this feature)
4254- `heuristics/∗diving/lpsolvefreq` to determine the frequency for resolving LP's during the execution of
4255 this heuristic [default: 1, use 0 for a dynamic setting based on the number of domain reductions]
4256 (* stands for eight diving heuristics to support this feature)
4257- `heuristics/shiftandpropagate/binlocksfirst` to set if binaries without locks should be preferred in ordering
4258- `heuristics/shiftandpropagate/maxcutoffquot` to select a maximum percentage of allowed cutoffs before stopping the heuristic (default is 0.0)
4259- `heuristics/shiftandpropagate/selectbest` to trigger if shiftandpropagate should select the best candidate in every round
4260 (set to FALSE for static order) (default is FALSE)
4261- `limits/autororestart` for triggering an automatic restart after this many nodes, or -1 for no auto restart [default is -1]
4262- `limits/softtime` to set a soft time limit (active only after first primal solution was found)
4263- `misc/allowobjprop` to allow objective function propagation
4264- `misc/allowdualreds` to allow dual reductions
4265- `misc/outputorigsol` to control whether at the end of a command line run the solution should be output in the orignal space
4266- `numerics/checkfeastolfac` to scale feasibility tolerance when checking the feasibility of best found solution
4267 after the solving process finished (e.g., checksol in scip shell)
4268- `separating/cutselrestart` for cut selection during restart copy process (`a`ge, activity `q`uotient) [default is `a`]
4269- `separating/cutselsubscip` for cut selection for sub SCIPs (`a`ge, activity `q`uotient) [default is `a`]
4270- `separating/disjunctive/maxconsdelay` to delay separation of disjunctive cuts if number of SOS1 constraints is larger than predefined value
4271- `separating/disjunctive/maxdepth` to define the node depth of separating disjunctive cuts
4272- `separating/disjunctive/maxinvcuts` to define the maximal number of disjunctive cuts investigated per iteration in a branching node
4273- `separating/disjunctive/maxinvcutsroot` to define the maximal number of disjunctive cuts investigated per iteration in the root node
4274- `separating/disjunctive/maxrank` to define the maximal permissible rank of a disjunctive cut that could not be scaled to integral coefficients
4275- `separating/disjunctive/maxrankintegral` to define the maximal permissible rank of a disjunctive cut that could be scaled
4276 to integral coefficients
4277- `separating/disjunctive/maxrounds` to define the maximal number of separation rounds of disjunctive cuts in a branching node
4278- `separating/disjunctive/maxweightrange` to define the maximal valid range of simplex tableau row weights
4282- new enum `SCIP_CONFIDENCE_LEVEL` for different levels of confidence for statistical tests.
4283- new struct `SCIP_DIVESET` that bundles options for SCIP's diving heuristics; all hard diving heuristics (those
4284 without `obj` at the beginning) include diveset and implement only the scoring callback.
4285- rename all file `*_vbc.?` to the more generic `*_visual.?`
4286- moved buffer memory handling to blockmemory/memory.?;
4287 remove files type_buffer.h, struct_buffer.h buffer.h buffer.c;
4288 removed functions SCIP*buffer*() from scip.? and replaced them by macros;
4289 redesigned buffer interface to be similar to block memory; added checks for strange sizes
4294- added scripts and targets for testing with xpress (see Makefile section)
4301- new parameter `DELHEADERS` for `uninstall`-target: scip headers are only removed when invoking `make uninstall DELHEADERS=true`
4302- added scripts check_xpress.awk, check_xpress.sh, evalcheck_xpress.sh and check_cluster_xpress.sh and target
4303 `testclusterxpress` and `testxpress`
4308- fixed bug in primal.c and tree.c by using SCIPinfinity() as a cutoffbound to delete child nodes
4309- fixed bug in lp.c which leads to wrong primal and dual feasibility
4310- fixed wrong handling of infinite activities and primal values in sepastore.c and lp.c
4311- fixed bug that led to an erroneous warning about the clock type
4312- fix behavior of `make install` which now sets symbolic links and short links to binaries and libraries
4313- fix bug which lead to wrong global bound tightenings in prop_genvbounds.c
4314- fix call to random generator for Windows operating systems in misc.c
4315- fixed again a bug in backward propagation of linear expressions in expression graph
4316- fixed bug in prop_symmetry.c, where an incorrect weak symmetry handling constraint got added.
4319 - fixed bug in heur_nlpdiving.c: wrong counting of fix variables
4320 - fix wrong handling of `SCIP_NLPSOLSTAT_LOCALINFEASIBLE` solution status in nlp.c
4321 - fix characterization of logic or constraints in SCIP's NLP relaxation
4324 - fixed wrong comparison when executing branching rule for external branching candidates
4325 - fix spatial branching on implicit integer variables
4326 - fix wrong comparisons of values larger/less than +/- SCIPinfinity() in branch.c, lp.c and sol.c
4327 - fixed problem with lpisrelax flag in probing mode when doing branch-and-price
4329- Constraint Handlers:
4330 - try to handle fixings of multi-aggregated variable in cons_sos1 presolving and avoid error
4331 - fixed bug in pseudoboolean constraint handler about negated variables
4332 - fixed assert in cons_soc.c: now soc with 1 lhs variable are allowed
4333 - fixed wrong assert in cons_indicator (slack variables might be replaced by active variables that have nonzero objective)
4334 - fix late creation of auxiliary LP in cons_nonlinear.c, which lead to a segmentation fault with lpi_spx2.cpp
4335 - fixed bug in cons_abspower.c: do not generate cuts with infinity right-hand-side anymore
4336 - fixed setting of enforcement flag for constraints created by reformulation in nonlinear constraint handlers
4337 - fixed bug in cons_indicator with handling local bounds
4340 - fix potential memory leak in SoPlex LP interfaces when setting invalid basis
4341 - fix potential memory leak in method SCIPgetConsCopy()
4342 - fix potential memory leak in method detectRedundantConstraints() of the knapsack constraint handler
4344- Interval arithmetic:
4345 - fix handling of infinite intervals in SCIPintervalIsEmpty()
4346 - fixed bug in intervalarith.c: bivariate quadratic equations may have been solved wrongly if second variable is unbounded
4348- Quadratic Constraints:
4349 - fix wrong sorting of bilinear terms in cons_quadratic
4350 - fix potentially tightening of LB/UB of a variable to +/- infinity in cons_quadratic
4351 - fixed bug in cons_quadratic.c which leads to an overflow when SCIP allocates memory for a dense matrix
4352 - fixed bug in cons_quadratic.c: do not generate linearization cuts for disabled constraints
4353 - fix missing clean phase of bilinear terms with zero coefficient in cons_quadratic.c
4355@page RN3_1 Release notes for SCIP 3.1
4357@section RN311 SCIP 3.1.1
4358*************************
4363- use clock average to reduce number of system calls via `timing/rareclockcheck` parameter
4364- added copy mechanism for conjunction constraints
4365- added revised lpi_xprs for using XPRESS as LP solver
4367Performance improvements
4368------------------------
4370- improved solving of LPs in OBBT propagator
4371- improved activity-delta computation and thereby propagation for linear constraints
4372- improved memory management of proximity heuristic
4373- disabled statistic timing in all subscips via new parameter `timing/statistictiming`
4378### New and changed callbacks
4380- rename array arcdatas in digraph to arcdata
4381- changes in clock type are now transferred to SoPlex
4382- corrected wrong primal bound in statistics for unbounded problems
4383- forbid to call SCIPfixVar() in `SCIP_STAGE_PRESOLVED` stage, which is not allowed since it calls SCIPchgVarLb/Ub()
4385### Deleted and changed API methods
4387- rename SCIPdigraphGetNodeDatas() to SCIPdigraphGetNodeData();
4388- rename SCIPdigraphSetNodeDatas() to SCIPdigraphSetNodeData()
4389- SCIPapplyProximity() has an additional parameter freesubscip, which causes the method to free
4390 the created subscip automatically at the end.
4392### New API functions
4394- SCIPhasPerformedPresolve() to check, e.g., whether LP duals are accessible
4395- SCIPconvertRealTo[Long]Int() to convert reals that represent integers to [long] ints.
4396- SCIPisDualfeasEQ() and related to perform checks w.r.t. to the dual feasibility tolerance
4397- SCIPdeleteSubproblemProximity() to free proximity subproblem manually as external caller
4399### Command line interface
4401- added dialog for writing the finite solution (calling SCIPcreateFiniteSolCopy() before writing)
4403### Interfaces to external software
4405- AMPL interface now returns dual multipliers if problem is an LP and presolving was turned off
4407### Changed parameters
4409- changed default value of parameter `heuristics/proximity/minimprove` to 0.02; previous value was 0.25
4410- changed default value of parameter `heuristics/proximity/usefinallp` to FALSE
4414- `timing/rareclockcheck` to call the system time less frequently, based on the current average time interval
4415 between two calls to SCIPsolveIsStopped(); the default value is FALSE
4416- `timing/statistictiming` to enable/disable all timers for statistic output of SCIP; the default value is TRUE
4420- renamed MIP matrix structure to `SCIP_MATRIX`
4421- changed the numeric values for `PRESOLTIMING` flags
4428- added Makefile support for cygwin 64 Bit
4429- allow to turn off block and buffer memory by the makefile parameters NOBLKMEM, NOBUFMEM, NOBLKBUFMEM;
4430 also remove the now superfluous makefiles for noblkmem, nobufmem, noblkbufmem
4435- fixed wrong conversion of reals representing negative integer values
4436- in debug mode, SCIP checks that no NaN's are introduced in SCIPsolSetVal()
4437- fixed bug 697 (and 699), calling SCIPsolve() after the problem was already solved and SCIPfreeSolve() was called now
4438 does nothing anymore
4439- added support for character `#` in variable names in old non-linear CIP format (i.e., names without `<` and `>`)
4440- fixed bug 702, removed too hard assert when casting too big values into `SCIP_Longint`
4441- branching for continuous variables with unbounded intervals now takes `branching/clamp` into account
4442- forbid aggregations with scalar smaller feastol or larger 1/feastol
4443- fixed bug 683, not recognizing errors/segfaults especially in free stage of SCIP by improving the check scripts
4444- fixed bug where quieting a message handler also disabled writing to files other than stdout
4445- fixed bug 708, special case of implications led to a fixing
4446- fixed bug, variable bounds detected wrong infeasibility
4447- another bug fix when computing the original variable sum of a given variable in SCIPvarGetOrigvarSum()
4448- fixed setting solution value of multi-aggregated var in xml-solution case
4449- fixed bug changing the variable type of an negated variable
4450- fixed numerical troubles in SCIPcreateFiniteSolCopy()
4451- fixed bug in SCIPpermuteProb(): if called before transforming the problem, data structures were not initialized yet
4452- fixed bug in aggregation procedure if two variables were of non-binary type but for one of the variables
4453 SCIPvarIsBinary() returned true
4454- treat activities of pseudo solutions as invalid when containing positive and negative infinity contributions
4455- fixed bug in GMI example: fractionality of slack variable is now computed correctly
4456- fixed LP interface of CPLEX: functions getBInv* return the correct sign of the coefficients.
4457- fixed bug in SCIPpermuteProb(), when called in transformed stage and non-active constraints exist
4460 - use dual feasibility tolerance for comparisons regarding reduced costs
4461 - fixed bug in prop_dualfixing: don't fix variables to infinite values during solving
4462 - fixed sign of the dual multipliers returned by AMPL interfaces for maximization
4464- Objective and Time Limit:
4465 - fixed wrong output of status when an objective limit was imposed but not reached yet
4466 - fixed the rare case that branching was performed even though strong branching found global bound changes leading to
4467 an infeasible/objlimit LP
4468 - fixed bug that objective limit was not reset correctly during SCIPfreeTransform() for maximization problems
4469 - fixed bug that hitting the time limit while solving a pure LP and then continuing the solving process lead to
4470 not solving the LP, but always creating a single child node until maximum depth is reached
4473 - fixed bug leading to an incorrect dual bound when solving probing LPs within a DURINGPRICINGLOOP heuristic
4474 - fixed bug in proximity heuristic which attempted to enter diving mode even at nodes without a constructed LP
4475 - fixed wrong pseudo cost updates during diving heuristic execution after backtracking
4476 - fixed bug in heur_oneopt: avoid bound violations if shift value is negative due to infeasibilities
4477 - fixed bug that reaching a solution limit by beforenode heuristics lead to disregarding the current node if the
4478 optimization process was restarted later
4479 - fixed bug in trysol heuristic not saving the best solution in maximization problems
4482 - fixed bug in presolving of abspower constraints that lead to wrong variable locks
4483 - allow to call SCIPmarkConsPropagate() in INITPRESOLVE stage
4484 - fixed bug in components presolver with handling of dual fixable variables: unboundedness was not detected,
4485 better handle components with single variables by dual fixing propagator
4486 - issues in component solving by presol_components do not lead to stopping the overall process, anymore, the component
4490 - fixed bug with freeing problem: need to reset objective limit
4491 - fixed memory leaks in case of erroneous parsing of constraints, e.g., non-linear constraints
4492 - fixed missing memory allocation for node data in digraphs
4495 - fixed bug in cons_quadratic which leads to wrong min/max activities
4496 - removed wrong break in cons_pseudoboolean
4497 - fixed bug in cons_varbound.c using the wrong constraint side for updating an upper bound
4498 - fixed bug in presolve of cons_nonlinear: wrong constraint upgrades may have been performed due to outdated bound
4499 information in expression graph
4500 - fixed bug in cons_setppc, wrongly aggregating variables if dual-presolving was disabled
4501 - fixed bug in cons_sos1: locks and events were not initialized if constraint was added to transformed problem
4502 - fixed bug in cons_setppc with dual presolving disabled
4503 - corrected copy of disjunction constraints
4506 - allow to read numbers like `42856.` in lp-format
4507 - fixed bug(?) in reader_mps: variables are now written in columns section even of they occur in no constraint
4508 and have an objective coefficient of 0 (otherwise, CPLEX and Gurobi cannot read the file)
4509 - fixed bug with reading `>=1` indicator constraints in LP-files
4510 - fixed bug in reader_lp which created two indicator constraints with the same name to trigger an equality
4511 - fixed bug when reading indicator constraints for linear constraints (equations/ranged rows) from MPS files
4513@section RN310 SCIP 3.1.0
4514*************************
4519- added breadth first search node selection
4520- new node selection rule UCT which balances exploration and exploitation by considering node visits
4521- added possibility to not set a cutoff bound in the LP solver (can be enabled by setting `lp/disablecutoff` to TRUE)
4522- added missing debugging solution check for cliques
4523- added a data pointer to each node of the `SCIP_DIGRAPH`
4524- SCIPgetVarCopy() will now copy the original bounds when called for an original variable
4525- added upgrade of continuous variables to implicit variables for linear equations even if the coefficient is
4527- probing supports implicit binary variables
4528- added scaling to computation of relative interior point in SCIPcomputeLPRelIntPoint()
4531 - added two methods to iterate over a sparse solution (`SCIP_SPARSESOLUTION`), see pub_misc.h
4532 - it is now possible to add an offset for the original problem instance, all original solutions will be initialized with
4533 this value and updated, when the offset is changed
4534 - extended and corrected dual feasibility checks for LP solution (controlled by parameter `lp/checkdualfeas`)
4536- Cuts and Separation:
4537 - the rank of cuts is now stored and taken into account to improve numerical stability
4538 - added possibility to separate a cutpool w.r.t. a given solution (instead of LP-solution)
4541 - new branching rule `cloud branching` that considers several alternative LP optima
4542 - additional vbc output added: branching information is printed earlier and also for nodes which were cut off
4543 - added support for strong branching with domain propagation in full strong and reliability pseudo cost branching
4544 - added strong branching with domain propagation support: in SCIPstartStrongbranch(), support for propagation can
4545 be enabled (uses the probing mode, some overhead compared to standard strong branching), after that
4546 SCIPgetVarStrongbranchWithPropagation() can be used to perform strong branching on a variable with previous domain
4547 propagation; similar to probing, valid bounds for variables are collected
4548 - strong branching with propagation can be enabled in fullstrong and relpscost branching rule
4549 - added possibility to store pricing norms of the LP solver (in addition to basis information) to speed up LP solving
4550 after a backtrack, e.g. in probing or strong branching with domain propagation
4551 - a pricer can now return that no further pricing should be done but rather early branching, even if it added variables
4554 - SoPlex (>= 1.7.0.5) can compute condition number of current basis matrix via LP interface
4555 - LPI files (lpi*.[h|c]) all moved from src/scip to src/lpi
4558 - added propagation method to cons_xor relying on Gaussian elimination, which can also produce feasible solutions
4559 - added first implication detection in cons_linear
4560 - cons_indicator can now try to construct feasible solutions from a cover
4561 - added possibility to forbid upgrading of linear constraints
4562 - new initial constraints are now added to the LP before solving a probing LP
4563 - first implementation of parsing for nonlinear constraints in CIP format
4564 - added upgrade from varbound constraints to set-packing constraints
4565 - added upgrade from bounddisjunction constraints to set-packing/logicor constraints
4566 - cumulative constraint handler adds disjunctive constraints (cumulative with capacity 1) for all jobs which cannot
4567 be processed in parallel
4568 - added new clique extraction algorithm for linear constraints
4569 - the slack variables of indicator constraints can now be scaled
4570 - added redundancy check of sides of ranged row varbound constraint
4571 - added coefficient tightening for ranged row varbound constraint
4572 - XOR constraint handler can add two extended formulations (flow/asymmetric, parameter `addflowextended/addextendedform`)
4573 - added multi-aggregation for binary variables with at most two uplocks and two downlocks, which emerge from set-
4574 partitioning or set-packing constraints
4575 - added upgrade from quadratic constraints to set-packing constraints
4576 - generalized the linking constraint handler
4579 - can now read and write CIP-files with (multi-)aggregated variables
4580 - all readers now take the global parameters `reading/dynamic{conss|cols|rows}` and `reading/initialconss` into account
4581 - added reader_pbm, which writes the constraint-variable incidence matrix in pbm format (possibly scaled to given size)
4582 - reader_osil can now read SOS1 and SOS2 constraints
4583 - reader_lp and reader_mps are now able to write and-constraints in form of their (weak/strict) relaxation
4584 - added reading capability to GAMS reader (if compiling with GAMS=true, requires a GAMS system)
4585 - added capability of writing SOS1/2 constraints to GAMS reader (introduces extra variables and equations)
4588 - new primal heuristics dual value
4589 - new LNS heuristic called `proximity`, which solves a problem in which a local branching constraint replaces the
4590 objective function which in turn is treated as additional constraint
4591 - new LP-based rounding heuristic (heur_randround) whose randomized rounding is biased towards the LP solution value;
4592 the heuristic uses the probing mode of SCIP to generate conflict clauses on the fractional variables
4595 - added new dual presolving for setppc-constraints
4596 - changed dualfix presolver to propagator such that dual fixing can also be applied during repropagation of the root node
4597 - added full-dual presolving step in setppc constraint handler
4598 - dual solution can now be displayed for pure LPs when no presolving was performed
4599 - added clique presolving for xor constraints
4600 - added presolving using pairs of variable bound constraints that use the same variables
4601 - added more presolving to cons_indicator, checking whether indicator/slack variables are aggregated
4602 - added presolve.{c,h} which should be used for all preprocessing mechanisms executed from within SCIP, corresponding to
4603 solve.{c,h} and also for presprocessing methods which can be called from different plugins or from the core to avoid
4605 - return error if variable should be fixed to infinity after presolving (LP-solvers do not handle this consistently)
4606 - in verblevel `SCIP_VERBLEVEL_FULL`, the number of non-zeros will be output for the original and presolved model
4607 - new presolving step for tightening logicor constraints using implication and clique information
4608 - several new presolving steps for linear and knapsack constraints, using gcd information and many more
4611 - added average gap based on primal-dual integral to solution statistics; can be disabled via parameter
4613 - the statistics now include the value of the first LP solved at the root node (without cuts)
4614 - added new statistic which distinguishes between internal nodes and leaves which got processed
4615 - new section `Root Node` in statistics, listing objective value, iterations and solving time for the first LP solved
4616 at the root node as well as final dual bound of the root node and LP iterations for processing the root node
4617 (those where listed in the `Solutions` section before, named `Root Dual Bound` and `Root Iterations`)
4619Performance improvements
4620------------------------
4622- allow multiaggregation of binary variables
4623- shorten conflicts and deriving global boundchanges from conflicts
4624- apply lowerbound provided by pricers already during pricing loop, stop pricing if the lower bound computed by pricing
4625 already exceeds the cutoff bound
4626- improved performance of SCIPcliquelistDel(), SCIPcliquetableAdd(), SCIPcliquetableCleanup()
4629 - strong branching LP solutions are checked for integrality
4630 - improved LP reoptimization for branch-and-price applications
4631 - improved numerical stability checks for LP solution
4632 - faster feasibility check of LP solutions (controlled by parameters `lp/checkprimfeas` and `lp/checkdualfeas`)
4635 - improved methods SCIPlpiGetBInv{Row,Col,ACol} for row representation in SoPlex LP interface
4636 - improved performance of method SCIPsolRetransform() when called during presolving with many aggregations
4637 - minor presolving performance improvements in cons_logicor.c and cons_knapsack.c
4638 - dual fixing presolver was turned into a propagator
4639 - many presolving improvements in constraint handlers
4640 - improved dual-presolving for setppc constraints in special cases
4643 - major improvements in pseudo-boolean constraint handler
4644 - performance improvement in domain propagation by marking constraints for propagation
4645 - added more constraint upgrading possibilities
4646 - improved handling of initial constraints created during solving
4647 - disabled scaling in feasibility check of nonlinear constraint handlers
4648 - conflict consisting of exactly two binary variables will be handled as set-packing constraint instead of an logicor
4649 constraint and the corresponding clique information is globally added
4650 - fasten repropagation for set-packing and -partitioning constraints
4651 - improved merging of and-constraints
4652 - disabled multi-aggregation in linear constraint handler when coefficients differ too much
4653 - improved multi-aggregation in linear constraint handler when only one variable in the aggregation has infinity
4655 - added upgradability for implicit binary variable cases for linear constraints
4657Examples and applications
4658-------------------------
4660- new textbook Gomory mixed integer cuts example
4665- removed all message length parameters in message.c and for printing error messages (not needed anymore)
4667### New and changed callbacks
4669- Domain Propagation:
4670 - added parameter `nmarkedconss` to SCIP_DECL_CONSPROP() callback which gives the number of constraints marked
4671 for propagation (these constraints are listed first in the conss array given as parameter).
4674 - Added parameter `nodeinfeasible` to SCIP_DECL_HEUREXEC() callback which states whether the current subproblem was
4675 already detected to be infeasible. In this case, the current LP solution might not respect local bounds and the
4676 heuristic must not assume that it does.
4679 - Added parameter `stopearly` to callback method SCIP_DECL_PRICERREDCOST(). This boolean pointer should be used by the pricer
4680 to state whether early branching should be performed, even if new variables were added in the current pricing round.
4683 - new possible return value `SCIP_DIDNOTFIND` for SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_BRANCHEXECPS(), and
4684 SCIP_DECL_BRANCHEXECEXT() callbacks to state that the branching rule searched, but did not find a branching.
4686### Deleted and changed API methods
4688- SCIPcalcMIR() takes an additional parameter sidetypes to determine which side of the rows to use
4689 (relevant for ranged rows)
4690- SCIPvarParseOriginal() and SCIPvarParseTransformed() now return the end of the parsed string
4691- SCIPgetConsCopy() now always captures the created constraint
4694 - Added parameter `nfracimplvars` to SCIPgetLPBranchCands()
4695 - SCIPgetLPBranchCands() can be used to retrieve the number of implicit integer variables with fractional LP solution
4696 value via an additional pointer; the corresponding implicit integer variables can be accessed together with their
4697 fractionalities and solution values in the same way as binary and integer variables before; the arrays are sorted such
4698 that binary and integer variables precede the implicit integer variables; the method SCIPbranchcandGetLPCands()
4699 has been modified in the same way
4701- LP and Cutting Planes:
4702 - Added parameter `sidetypes` to SCIPcalcMIR() to specify the specify row side type to be used.
4703 - Added parameter `cutrank` to SCIPcalcMIR() and SCIPcalcStrongCG() which stores the rank of the returned cut;
4704 via SCIProwChgRank() the rank of a cut can be changed (default rank is 0)
4705 - Added parameter `infeasible` to SCIPaddCut() which is a pointer to store whether the cut is infeasible for the
4707 - SCIPgetLPObjval() now returns the LP value of the current (suboptimal) basis if the iteration limit is hit during LP
4708 solving (instead of -infinity); this value is not necessarily a valid dual bound and must not be used as such, but can
4709 be used as an objective estimate, e.g., if strong branching is simulated using the probing mode
4710 - removed parameter `normtype` from function SCIPcomputeLPRelIntPoint()
4713 - Added parameter `lazyconss` to SCIPwriteMIP() to swith writing removable rows as lazy constraints.
4714 - Added parameter `enablepropagation` to SCIPstartStrongbranch(), which can be used to enable strong branching
4715 with domain propagation.
4716 - SCIPstartStrongbranch() has a new parameter `propagate` to enable or disable propagation support for strong branching
4717 - New method SCIPgetVarStrongbranchWithPropagation() which performs strong branching with propagation on a variable.
4718 - Added parameter `endptr` to SCIPparseVar() which stores the final string position after parsing.
4720### New API functions
4722- added SCIPdebugCheckConss() to the debugging mechanism and therefore created a `SCIP_SOL` (in original space) in debug.c
4723- before copying solutions to the original solution candidate storage, infinite solution values can now be removed using SCIPcreateFiniteSolCopy()
4724- SCIPsortLongPtrRealBool(), SCIPsortLongPtrRealRealBool(), SCIPsortLongPtrRealRealIntBool() and corresponding
4725 methods for sorting, insertion and deletion
4726- SCIPstoreSolutionGap() in scip.c, to store the gap when the first and last solution is found
4727- SCIPwriteCliqueGraph() which allows to write a graph with node weights for fractional variables
4730 - SCIPconshdlrIncNCutsFound(), SCIPsepaIncNCutsFound() and SCIPsepaIncNCutsFoundAtNode() to increase the number of found cuts
4731 - SCIPseparateSolCutpool() to separate a cutpool w.r.t. a given solution
4733- Constraint Handlers:
4734 - New method SCIPconshdlrGetStrongBranchPropTime() which returns the time used for domain propagation methods
4735 of the constraint handler during strong branching.
4736 - New method SCIPconsIsMarkedPropagate() which returns whether a constraint is marked for propagation.
4737 - New methods SCIPconsAddUpgradeLocks() and SCIPconsGetNUpgradeLocks() to increase or get the number of upgrade
4738 locks of a constraint.
4739 - New method SCIPgetNCheckConss() which returns the number of checked constraints.
4742 - New methods SCIPsparseSolGetFirstSol() and SCIPsparseSolGetNextSol() to get the first sparse solution
4743 or iterate over the sparse solutions, respectively.
4744 - New methods for the `SCIP_QUEUE` data structure in pub_misc.h to handle a (circular) queue, e.g., SCIPqueueCreate(),
4745 SCIPqueueFree(), SCIPqueueInsert(), SCIPqueueRemove(), SCIPqueueFirst(), SCIPqueueIsEmpty(), SCIPqueueNElems()
4746 - New method SCIPgmlWriteNodeWeight() to write a node section including weight to a .gml graph file.
4747 - New methods for hash tables: SCIPhashtableRemoveAll(), SCIPhashtableGetNElements(), SCIPhashtableGetLoad()
4748 - New methods in pub_misc.h to handle a resource activity, e.g., SCIPactivityCreate(), SCIPactivityFree(),
4749 SCIPactivityGetVar(), SCIPactivityGetDemand() ...
4750 - New methods for digraphs: SCIPdigraphResize() to resize the graph and SCIPdigraphSetNodeDatas() and
4751 SCIPdigraphGetNodeDatas() to set and get the data attached to the nodes.
4753- Domain Propagation:
4754 - New method SCIPpropGetStrongBranchPropTime() which returns the time spent by a domain propagator during strong branching.
4755 - New methods SCIPmarkConsPropagate() and SCIPunmarkConsPropagate() to (un)mark a constraint for propagation.
4757- LP and Cutting Planes:
4758 - New methods SCIPchgRowLhsDive() and SCIPchgRowRhsDive() to change left and right hand side of a row during diving.
4759 - Added parameter `cutoff` to SCIPsolveDiveLP(), SCIPsolveProbingLP(), and SCIPsolveProbingLPWithPricing()
4760 which is a pointer to store whether the diving/probing LP was infeasible or the objective limit was reached.
4761 - SCIPgetFirstLP{Dual/Lower}boundRoot() which return the value of the first LP solved at the root node
4762 - SCIPgetNRootFirstLPIterations() which returns the number of LP iterations for the first LP solved at the root node
4763 - SCIPlpiGetNorms(), SCIPlpiSetNorms() and SCIPlpiFreeNorms() for getting the LP pricing norms from the LP
4764 solver, loading them back into the solver and freeing the data
4765 - New method SCIPgetFirstLPTime() and SCIPgetNRootFirstLPIterations() to return time and iterations for the first LP solve
4766 and SCIPgetFirstLPDualboundRoot() and SCIPgetFirstLPLowerboundRoot() to return the first root LP dual and lower bound.
4767 - New method SCIPprintDualSol() which prints the dual solution for a pure LP (works only with preprocessing disabled).
4768 - New method SCIPisCutApplicable() which returns whether a cut is good enough to be applied.
4771 - the main output routine of message.c (`bufferMessage` now handleMessage) has been rewritten: it now does not need
4772 a copy of the string to be output anymore, which makes the code much simpler (and also faster); it is passed a
4773 function pointer to the output function and uses it to directly output the (buffered) messages
4774 - New generic messagehandler output callback method SCIP_DECL_MESSAGEOUTPUTFUNC().
4775 - Removed parameter `msglength` from callback method SCIP_DECL_ERRORPRINTING().
4776 - New method SCIPmessageVPrintError() to print an error message.
4777 - Removed method SCIPmessagePrintWarningHeader().
4780 - New method SCIPparamGetCharAllowedValues() to get the allowed values for a char parameter.
4781 - New method SCIPgetParam() to get the parameter with a given name.
4784 - SCIPapplyProbingVar() in prop_probing.h
4785 without deteriorating its objective value
4786 - SCIPshrinkDisjunctiveVarSet(), which takes an set of variables with corresponding bounds and boundtypes, and
4787 tries to derive global boundchanges and also to shorten this set of variables by using cliqe, implication and
4788 variable bound information
4789 - SCIPselectVarStrongBranching() to get the variable that fullstrongbranching would select
4790 - New method SCIPvarGetValuehistory() to get the value-based history of a variable.
4793 - New method SCIPdoNotMultaggr() which returns whether multi-aggregation was disabled.
4794 - New method SCIPcreateFiniteSolCopy() to create a copy of a solution with infinite fixings removed.
4795 - New method SCIPadjustImplicitSolVals() which sets implicit integer variables to an integer value in the given
4796 solution without deteriorating its objective value.
4797 - New method SCIPcopyOrig() to copy the original problem. Analoguosly, use SCIPcopyOrigProb(), SCIPcopyOrigVars(),
4798 and SCIPcopyOrigConss() to copy original problem data, variables, or constraints, respectively.
4799 - New method SCIPwriteCliqueGraph() to write the clique graph in GML format into a given file
4800 - New method SCIPaddOrigObjoffset() to add an offset to the objective function.
4801 in original space and updates all orignal solutions correspondingly
4802 - New method SCIPcopyImplicationsCliques() to copy implications and cliques to a copied SCIP instance.
4803 - New method SCIPgetOpenNodesData() which returns all unprocessed nodes.
4804 - Added parameter `endline` to SCIPprintDisplayLine() to switch printing a newline symbol at the end of the line.
4805 - New method SCIPgetNLimSolsFound() returning the number of feasible primal solution respecting the objective limit.
4807### Command line interface
4809- allow dialog option to write clique graph
4810- dual solution values can now be obtained in the interactive shell after solving a pure
4811 LP without presolving
4813### Interfaces to external software
4815- new SoPlex 2.0 interface, can be enabled with `LPS=spx2`
4816- add support for SOS1 and SOS2 constraints to AMPL interface (see `interfaces/check/testset/SOS/sos?a.mod` for example)
4817- added copy of GAMS interface from COIN-OR/GAMSlinks project; GAMS-reader in SCIP can now read model instances from .gms files
4818- beta version of a python interface for the scipoptsuite is now available under interfaces/python
4819- beta version of a Java native interface is now available under `interfaces/jni`
4821### Changed parameters
4823- parameter `branching/scorefunction` has new value `q` for for `q`uotient branching score function
4824- replaced parameter `lp/checkfeas` by two parameters `lp/checkprimfeas` and `lp/checkdualfeas` to decide on primal and dual
4825 feasibility checks individually
4826- removed all local parameters `reading/(READER)/dynamic{conss|cols|rows}` and replaced them by global parameters
4827 `reading/dynamic{conss|cols|rows}`
4828- changed default value of parameter `numerics/dualfeastol` to 1e-7 for safer dual bounds from LP solver
4829- new possible values for parameter `heuristics/shiftandpropagate/sortkey` for sorting variables w.r.t. their norm,
4830 default changed from `u` to `v`, which means sorting downwards by violations
4833 - changed type of parameters `constraints/bivariate/scaling`, `constraints/quadratic/scaling`, `constraints/soc/scaling`
4834 from boolean to character
4835 - changed default for `constraints/{abspower,bivariate,nonlinear,quadratic,soc}/scaling` to off
4836 - changed default max coefficient for big-M constraint to be initial from 1e6 to 1e9
4839 - changed default value of gomory cut separation parameter `separating/gomory/maxrank` from 0 to 3, to take also gomory
4840 cuts that could not be scaled to integral coefficients, with maximal rank 3 into account
4841 - remove parameter `separating/closecuts/relintnormtype`
4845- `branching/checksol` and `branching/heursbsol` to specify whether the strong branching LP solution
4846 should be checked for feasibility and whether a simple rounding heuristic should be run on this solution
4847- `branching/firstsbchild` and `branching/forceall` to specify the first child node to be
4848 investigated during strong branching (`u`p, `d`down, `a`uto) and whether always both children should be solved (only for
4849 strong branching with domain propagation, per default, the second child is not looked at when the first is infeasible)
4850- `conflict/fullshortenconflict` to decide whether we want to stop shortening a conflict set, when no
4851 global bound changes can be found anymore
4852- `conflict/maxvarsdetectimpliedbounds` to decide whether the a valid conflict of what maximal length
4853 will be used to derive global bound changes
4854- `constraints/{linear,knapsack}/detectcutoffbound` and `constraints/{linear,knapsack}/detectlowerbound`
4855 to enable/disable detection of constraint parallel to the objective function that will add an cutoffbound or an
4856 lowerbound respectively and these constraints will be prevented from entering the LP
4857- `constraints/and/upgraderesultant` to upgrade resultants of and constraints from binary to implicit binary variables, default is TRUE
4858- `constraints/abspower/scaling` and `constraints/nonlinear/scaling`
4859- `constraints/indicator/scaleslackvar` for scaling of the slack variable in indicator constraints
4860- `constraints/indicator/trysolfromcover` for trying to construct a feasible solution from a cover
4861- `constraints/linear/checkrelmaxabs` for checking linear constraints with a side of 0.0 relative to
4862- `constraints/linear/detectpartialobjective` to enable/disable the detection of sub-equations of the objective function
4863- `constraints/logicor/strengthen`, should pairwise constraint comparison try to strengthen constraints by removing superflous non-zeros?
4864- `constraints/xor/addextendedform` to add an extended formulation in XOR-constraints
4865- `constraints/xor/addflowextended` to add use the extended flow formulation in XOR-constraints
4866- `heuristics/<heurname>/lplimfac` for LNS heuristics to limit the number of LPs solved in a subproblem
4867 the maximum absolute value in the activity instead of 1.0
4868- `heuristics/shiftandpropagate/fixbinlocks` for fixing binary variables with no locks in one direction to the corresponding bound
4869- `heuristics/shiftandpropagate/collectstats` which decides whether variable statistics are collected
4870- `heuristics/shiftandpropagate/impliscontinuous` to decide whether implicit integer variables are treated as continuous variables
4871- `heuristics/shiftandpropagate/preferbinaries` and `heuristics/shiftandpropagate/stopafterfeasible`,
4872 which decide whether binaries should be shifted first and the shifting should be stopped when no violations are left
4873- `lp/disablecutoff` to toggle usage of LP cutoff bound (0: enabled, 1: disabled, 2: auto = disabled if pricers are used)
4874- `misc/calcintegral` (default TRUE) to trigger calculation of primal-dual integral
4875- `misc/finitesolutionstore` to switch whether infinite fixings should be removed from solutions before
4876 copying them to the original solution store
4877- `misc/permuteconss` and `misc/permutevars` to control whether variables and/or constraints should be permuted, if permutationseed != -1
4878- `presolving/components/feastolfactor` to increase the feasibility tolerance in all sub-SCIPs, when solving a component
4879- `propagating/obbt/conditionlimit` to discard instable LP bases
4880- `reading/(READER)/initialconss` that determines whether model constraints are initial
4881- `reading/cipreader/writefixedvars` for disabling printing of fixed variables in CIP format
4882- `reading/lpreader/aggrlinearization-ands` and `reading/mpsreader/aggrlinearization-ands` to enable/disable
4883 the printing of the weak or strict relaxation of and-constraints in LP and MPS format, respectively
4884- `reading/lpreader/linearize-and-constraints` and `reading/mpsreader/linearize-and-constraints` to
4885 allow and-constraints to be linearized when printing in LP and MPS format, respectively
4886- `separating/feastolfac` to allow dynamic decrease of relaxation feasibility tolerance depending on feasibility to applied cuts,
4887 i.e., allow relaxation solutions to have a primal infeasibility of at most this factor times the infeasibility of applied cuts
4888- `separating/gomory/sidetypebasis` to decide whether the sides of ranged rows should be determined from the basis status
4889- `separating/oddcycle/cutthreshold` to run odd cycle separation if not enough cuts have been found
4890- `separating/zerohalf/delayedcuts` to use the delayed cutpool for the zerohalf separator
4891- `write/allconss` to enable that all constraints are written
4892- `write/genericnamesoffset` when writing a generic problem to define an offset on the variable numbering
4896- New structure to store value-based branching and inference history (see pub_history.h).
4897- new data structure for (circular) queues (`SCIP_QUEUE`)
4898- hash tables will now increase dynamically
4899- Moved LP solver interfaces to subdirectory `src/lpi`.
4904- added McNemar tests and Wilcoxon signed rank tests to cmpres.awk evaluation scripts
4905- added passing MEM option of testgams(cluster) target as workspace option to GAMS jobs
4906- extended test scripts by statistical tests
4913- default flag for ZIMPL is now `auto`, which means that it is built if and only if GMP is available (GMP=true)
4914- fixed make install for older Mac systems where install command does not have option -t
4915- dropped support for Ipopt < 3.10
4920- fixed bug when adding (global) clique, implications or variable bound information in solving stage that lead to
4921 global bound changes which contradict local bounds and therefore need to be stored as pending bound changes
4922- unlinking a solution now copies solution values smaller than SCIPepsilon() avoiding some feasible solution in the
4923 transformed problem to be infeasible in the original problem
4924- fixed bug when flushing the warning buffer when SCIP is closed
4925- fixed bug when a bound change contradicts a local bound and is stored as pending, but the contradicting local
4926 bound becomes global afterwards (--> node where pending bound change is valid can be cut off)
4927- fixed statistics bug: externally given solutions and new solutions found while transforming existing ones
4928 are now listed in line `other solutions` of primal heuristics statistics
4929- fixed bug in random generators SCIPgetRandomInt() and SCIPgetRandomReal() for large intervals
4930- make sure that bound changes of negated original variables are correct
4933 - fixed bug w.r.t. changing the variable branching priority beyond the problem stage
4934 - allow again branching on continuous variables with huge bounds
4937 - fixed bug in sepa_cgmip computeObjWeightSize() w.r.t. equal sized rows
4938 - fixed wrong bound calculation in sepa_rapidlearning
4939 - fixed bug in flowcover separator to exclude unconstrained rows in aggregation
4942 - fixed bug that lead to resolving the LP after diving instead of restoring the buffered solution
4943 - fixed rare bug with conflict analysis and LP/LPI having different states after diving
4944 - fixed several bugs in lpi_grb
4945 - fixed wrong strong branching results in lpi_grb.c and an invalid write
4946 - fixed bug in handling max-function in ampl interface; added support for min-function
4949 - fixed bug in prop_dualfix w.r.t. to fixing of variables to infinity after presolving
4950 - fixed wrong presolving finished status which sometimes occurred when the time limit was hit during presolve
4951 - fixed bug where a limit on presolving rounds was exceeded by 1
4952 - fixed minor bugs in presolving in cons_setppc.c and cons_logicor.c
4953 - fixed minor bug in cons_linear w.r.t. disabled presolving
4956 - fixed bug in genvbounds propagator occurring when objective offset or scale changes after a restart
4957 - fixed bug in genvbounds propagator by replacing non-active variables on right-hand side after presolving
4960 - fixed memory bug in reader_mps
4961 - fixed several minor bugs with handling of memory when writing aggregated variables (reader_lp, reader_mps)
4962 - fixed bug in reader_lp when writing bilinear terms (product sign was missing)
4963 - fixed bug in reading indicator constraints in mps-format
4964 - nonlinear readers now create auxiliary objective variables and constraints always as initial and not removable
4965 in order to avoid unbounded LPs due to loose variables with infinite best bound
4968 - fixed several bugs where variables or constraints were not freed correctly
4969 - do not multi-aggregate variables if the constant would be a huge value in order to avoid numerical troubles
4970 - fixed bug with infinite multi-aggregation constants
4971 - fixed output of aggregated variables in indicator constraints in lp and mps-format
4972 - improved handling of initial constraints: constraints which are initial, but added during the search to an already
4973 treated node are kept and added to the LP at every node where they are active
4974 - fixed bug in cons_superindicator concerning names of upgraded constraints
4975 - fixed bug in cons_indicator with trying to create solution in problem stage
4976 - fixed bug in cons_orbitope with fixing upper right triangle in non-root nodes
4981- new SCIP Optimization Suite homepages
4983@page RN3_0 Release notes for SCIP 3.0
4985@section RN302 SCIP 3.0.2
4986*************************
4991- reading erroneous CIP files can now output some indication of syntax errors
4992- can now run splint on core files
4993- cons_xor now uses the integral variable in propagation
4994- allowed to switch on/off the solution debugging
4996Performance improvements
4997------------------------
4999- improved SCIPlpiAdd{Cols,Rows}() in SoPlex LPi
5001Examples and applications
5002-------------------------
5007### New API functions
5009- SCIPmarkColNotRemovableLocal() and SCIPmarkRowNotRemovableLocal() to forbid removal of an column/row
5010 from the LP in the current node
5011- SCIPmessageVPrintError()
5013### Command line interface
5015- can now output the solutions in the solution pool in the interactive shell
5017### Interfaces to external software
5019- updated Mosek LP interface to compile with Mosek 7
5024- fixed bugs in solution counting
5025- fixed fieldtypes in sorting template
5026- fixed bug concerning the userinterrupt flag, which was not reset
5027- fixed solution collection when counting solutions
5028- fixed bug with storing original solutions
5029- fixed bug with infinite multi-aggregation constants
5030- fixed bug that removing reverse implication did not reset closestvblpcount
5031- fixed bug that duplicate solutions stopped copying of solutions to original solution candidate store
5032- forbid branching on variables with huge bounds; such huge values cannot be enumerated with fixed precision
5033 floating point arithmetics
5034- fixed bug that Ipopt's error message was not fully shown due to exiting before the message handler buffer was emptied
5035- unlinking a solution now copies solution values smaller than SCIPepsilon() avoiding some feasible solution in the
5036 transformed problem to be infeasible in the original problem
5037- allow to add columns (rows) with nonzero indices beyond current number of rows (columns) in SoPlex LPi
5038- updated get.ASL script to cope with broken ftp access to netlib server
5041 - fixed bugs with freeing C++ object data for problem and variables
5042 - fixed memory leak in lp.c (probably never occurred so far since array was not used)
5043 - fixed bug in sepa_zerohalf.c where the maxcuts(root) parameters led to an invalid memory allocation call
5046 - fixed assert in solve.c with branched status and LP reached the objective limit
5047 - fixed bug in heur_oneopt.c and heur_clique.c which was caused by side-effects when calling SCIPconstructLP(); when
5048 adding new variables in this method (e.g. adding new variables needed for a relaxation), this changes the variables
5050 - fixed problem that diving did not save status for infeasible LPs
5051 - fixed bug in SCIPlpComputeRelIntPoint() with wrong iteration limit and with wrong recompution
5052 - fixed bug that old LP size was not updated for deadend if no LP was solved
5055 - fixed issues with ungraceful termination when encountering unsupported expression operands in AMPL interface
5056 - fixed bug in backward propagation of linear expressions in expression graph
5059 - fixed potential performance issue with tree depth always assumed to be zero when propagating in probing mode
5060 - fixed bug in prop_vbound w.r.t. creation of variables during the search
5061 - fixed several bugs in propagation of cons_xor: need to take integral variables into account
5062 - fixed bug in cons_abspower.c handling infinity values in propagation
5063 - fixed bug in cons_and.c when a constraint was not correctly propagated which led to wrong dual-presolve reductions
5064 - fixed bug in cons_abspower: wrong infinity check when propagating bounds
5067 - fixed bug that the number aggregated variables were not counted in presol_inttobinary.c
5068 - fixed bug in presol_domcol: locks are now checked to see whether rounding was forbidden for a variable
5071 - fixed bug in reader_gms.c w.r.t. writing nonlinear expressions with polynomials with constants
5072 - fixed bugs in parsing bounds from CIP-files, in reader_gms and AMPL interface
5073 - fixed bug when reading a mps formated file with a missing bound in the bound section
5076 - fixed bug in cons_bounddisjunction with satisfied literal of multi-aggregated variable
5077 - fixed bug in upgrade method of cons_soc
5078 - fixed issue with negated variables in cons_xor.c
5079 - fixed several asserts in cons_xor presolving
5080 - fixed bug in cons_xor.c calling method on null pointer row
5081 - fixed bug using a too hard comparison on the objective-infeasible-decision in constraint enforcement
5082 - fixed possible cycling in enforcement of nonlinear constraints due to too early removal of newly added cuts from LP
5083 - fixed bug wrongly removing constraints locally while counting
5084 - fixed bugs in cons_bivariate.c when the nonlinear function is not differentiable on the boundary of the domain
5085 - fixed bug in cons_indicator.c:SCIPmakeIndicatorFeasible() with handling fixed variables
5086 - fixed bug in cons_integral: check integrality of implicit integer variables when a solution is checked for feasibility
5087 - fixed bug in Undercover with `pseudo-`quadratic constraints
5088 - fixed bug with quadratic constraints not being upgraded
5089 - fixed bug in intervalarith.c: bivariate quad. equations may have been solved wrongly if second variable is unbounded
5092 - fixed bug in sepa_zerohalf.c not copying the displays to the subscip, but still changing a display parameter there
5093 - fixed iteration limit determination in sepa_closecuts
5094 - fixed bug in sepa_closecuts: need to make sure that variable values of separation point satisfy bounds
5095 - fixed bugs in sepa_oddcylce: number of arcs have to be adjusted, handle implicit binary variables,
5096 fixed bug in heuristic separation method, fixed asserts
5097 - fixed wrong bound calculation in sepa_rapidlearning
5099@section RN301 SCIP 3.0.1
5100*************************
5105- added delayed cutpool which only gets separated if the sepastore is empty after a separation round
5106- sepa_cgmip can now take the objective row into account
5107- added possibility to run clang compiler
5108- statistics now include output on number of solutions that respect objective limit
5110Performance improvements
5111------------------------
5113- also copying active tight cuts from the delayed cut pool when calling SCIPcopyCuts()
5114- sort genvbounds only when root node is finished; apply more often
5116Examples and applications
5117-------------------------
5122- when using an objective limit, heuristic characters are not displayed any longer for worse solutions
5124### Deleted and changed API methods
5126- fixed spelling in the method name SCIPgmlWriteClosing()
5128### New API functions
5130- SCIPgetNLimSolsFound() to get number of solutions that respect the objective limit
5135- fixed issue with applying the effective root depth during the search
5136- fixed bug concerning usage of dualbound and lowerbound
5137- fixed bug trying to color probing nodes, which are not added to the vbc output anymore
5138- fixed bug in sorting template
5139- fixed bug leading to removing a ranged row parallel to the objective function, although one of the sides was still needed
5140- fixed a bug correcting the binvarssorted flag in cons_linear.c
5141- fixed bug in cons_varbound.c not resolving multi-aggregated variables
5142- relaxed assert in SCIPvarCh{Lb,Ub}{Global,Local} that new bound must be tighter to feastol
5143- fixed contra-intuitive behavior when using SCIP with objective limits and solution limit at the same time;
5144 SCIP now only stops when sufficiently many solutions better than the objective limit have been found
5145- fixed bug when adding binary implications with non-vartype binary variables
5146- fixed bug adding binary implications on binary variables with type != `SCIP_VARTYPE_BINARY`
5147- fixed bug concerning different tolerances for reached objective limit in case of pricing with fastmip
5150 - fixed bug which disabled iteration limit in SCIPlpSolveAndEval()
5151 - ensure consistency of LP bounds during OBBT diving, i.e., that lower <= upper holds exactly
5152 - set lpsolstat to `SCIP_LPSOLSTAT_NOTSOLVED` in SCIPchg{Lp,Dual}feastol()
5153 - use tighter dual feasibility tolerance for LPs solved during optimization-based bound tightening
5154 - fixed bug with unflushed LP arising from global bound changes in strong branching
5157 - fixed issue with deleting varbound constraints in case the bound change was not applied
5158 - fixed bugs in parsing dis-/conjunctive constraints
5159 - fixed bug with handling of empty logicor and bounddisjunction constraints
5160 - fixed issue in cumulative constraint and separation
5161 - fixed bug when sorting knapsack constraints with the same weights
5162 - fixed bug resulting in trying to delete an upgraded linear constraint a second time in exitpre callback
5163 - fixed minor bug in conjunctive constraint handler printing wrong constraint
5164 - fixed bug in disjunctive constraint handler when enforcing a constraint
5165 - fixed behaviour change of indicator constraint handler when solving another instance after solving one using the
5167 - fixed several issues in cumulative constraint handler
5168 - fixed bug in cumulative constraint handler w.r.t. getting active variables
5169 - fixed bug in cumulative constraint handler concerning conflict analysis
5171- LPI and Interfaces:
5172 - fixed bug in CppAD in connection with abspower constraints
5173 - fixed bug in CppAD when using signpower functions with expression pointers that do not fit into an unsigned int
5174 - better handling of generalized (Lagrangian) variable bounds that are not in the LPI
5175 - fixed wrong basis rstat values in CPLEX LPI
5176 - fixed bug with LP not being flushed after bound changes on columns that are not in the LPI
5177 - methods SCIPlpiIs{PrimalFeasible,DualFeasible,DualUnbounded}() in SoPlex LPi now check that the LP is not perturbed,
5178 which may happen when stopping due to iteration or time limit
5179 - fixed inconsistencies between methods SCIPlpiIs{PrimalFeasible,DualFeasible,Optimal,...} in SoPlex LPi
5182 - fixed bug when adding linear constraints with non active variables in solving process, during propagation this
5183 resulted in changing the row, which is not possible for unmodifiable constraints/locked rows
5184 - fixed small issue in pseudo objective propagator w.r.t. propagating the lower bound globally
5185 - fixed bug in cons_orbitope: in rare cases one cannot repropagate
5186 - fixed bug of wrong result code in propagation in prop_genvbound.c
5189 - fixed bug in copying nonlinear constraints during presolve (resulted
5190 in wrongly declaring instances as infeasible when using component presolve)
5191 - fixed bug in copying nonlinear constraints during presolve (nonlinear part was not copied)
5194 - fixed wrong solving status (OPTIMAL) in case an unbounded solution was provided or found by heuristic before presolve
5195 - fixed bug in heur_subnlp running with tightened tolerances: sumepsilon must be tightened like feastol and epsilon
5196 - fixed bug in nlp diving heuristic for fractional variables with values slightly outside of their domain
5199 - fixed several numeric issues
5200 - fixed numerical bug in conflict.c relaxing bounds while keeping an infeasibility proof
5201 - fixed feasibility decision bug when replacing inactive variables by their active counterparts, which might change the
5202 redundancy status of a bounddisjunction constraint due to numerics
5203 - fixed numerical bug adding a relaxed bound for conflict analysis in cons_varbound
5204 - fixed numerical bug in conflict analysis of genvbounds propagator
5206@section RN300 SCIP 3.0.0
5207*************************
5212- SCIPcomputeLPRelIntPoint() with normtype=`s` now uses homogenized LP for computing rel.int. point too and allow to
5213 set relaxrows = FALSE
5214- new column showing the pseudo objective value
5215- digraph structure added to misc.c and pub_misc.h that can be used to handle directed graphs, compute undirected
5216 components in the graph and sort these components (almost) topologically
5217- SCIP does now print an info message when the root LP could not be solved or is unbounded
5218- added counter and clock for SCIPcopy() calls
5219- correct initialization of steepest edge weights with SoPlex 1.6.0.4
5220- parameters can now be fixed, which means that their value cannot be changed unless they are unfixed, first;
5221 the fixing status of a parameter is copied to sub-SCIPs, which allows to ensure that certain parameters
5222 are also not changed when, e.g., heuristics change emphasis settings or also specific parameters
5223- automatic transfer of original solutions (e.g., provided by the user, from solution pool, after restart, from heuristic
5224 adding original solution during solve) to the transformed space (might fail due to, e.g., dual fixings)
5225- added possibility to use GUBs for lifting knapsack cuts (disabled)
5226- added pre- and post-conditions in doxygen documentation for all methods of scip.{c,h}
5227- added zeroobj heuristic that solves a copy of the problem without an objective function and with quite strict limits
5228 on the number of nodes and LP iterations
5229- complete reworking of the vbounds propagator: it now takes into account variable bounds, cliques and implications,
5230 stores bounds of variables which were changed and performs a forward propagation from these bounds, i.e., tries to
5231 derive new bounds for other variables; during propagation, bound changes are propagated in an (almost) topological order
5234 - full version of cumulative constraint handler
5235 - new constraint handler `superindicator` for indicator constraints with slack constraints of arbitrary type
5236 - implemented first clique lifting procedure in cons_setppc.c (by default is off)
5237 - the conjunction and disjunction constraint handlers are now able to parse their CIP output format
5240 - better handling of memory limits, in particular for large problems
5241 - estimate memory consumption for sub-SCIP and do not copy them if close to memory limit
5244 - time for initpre and exitpre methods is now also measured in presolving time
5245 - added dual presolving for and-constraints difficult instances (no guarantees)
5246 - oneopt can now be called before presolving
5247 - added a presolving step in the disjunctive constraint handler, removing disjunction, where a sub-constraint was
5248 deleted, which means this sub-constraint is redundant, which again means it is always TRUE or will be enforced by
5250 - added new presolver convertinttobin, which converts bounded integer variables to their binary representation, e.g.
5251 for integer variable 0 <= x <= 10 the binary variables y0, y1, y2 and y3 are created, such that
5252 1 y0 + 2 y1 + 4 y2 + 8 y3 <= 10 and x = 1 y0 + 2 y1 + 4 y2 + 8 y3
5253 - added new presolver gateextraction, which tries to find and-gates/constraints which are linearized
5254 e.g. (x + y + z >= 1, x + y <= 1 and x + z <= 1 => x == AND(~y,~z)), in special cases it also detects set-partitioning
5255 constraints e.g. (x + y + z >= 1, x + y <= 1, x + z <= 1 and y + z <= 1 => x + y + z == 1));
5256 gate-extractor is also able to detect logicor constraints and set-packing/-partitioning constraints with the same
5257 variables, to upgrade these both constraints to a set-partitioning constraint
5258 - added new presolver components, that searches for independent components in the problem structure and solves
5259 these components as sub-SCIPs when they are small enough (per default <= 20 discrete variables, nodelimit of 10000)
5260 - added new presolver domcol that looks for dominated columns in a MIP and tries to fix them
5263 - CNF reader now creates feasibility instances per default, usage of an objective has to be set by a parameter
5264 - added reader for MI(NL)Ps in OSiL (Optimization Services Instance Language) format
5267 - new statistics and new statistic output messages
5268 - number of presolving calls of plugins is counted and displayed in the statistics,
5269 can be accessed via SCIPpresolGetNCalls() and SCIP{prop/conshdlr}getNPresolCalls()
5270 - the statistics shows for a branching rule the number of calls for LP, extern and pseudo candidates
5271 - new switch `SCIP_STATISTIC` and new macros SCIPstatisticMessage(), SCIPstatisticPrintf() and SCIPstatistic() to output
5272 statistic and execute code lines which are only needed therefor. Works as `SCIP_DEBUG` and SCIPdebugXyz()
5273 - added statistics on the number of cuts/rows that have actually been applied to the lp for each constraint handler and separator;
5274 use SCIPcreate(Empty)RowCons() and SCIPcreate(Empty)RowSepa() to support the statistics.
5277 - new propagators obbt and genvbounds for MINLP
5278 - new NLPI parameter `SCIP_NLPPAR_FASTFAIL` to enable convergence checks in NLP solver to stop early on seemingly
5279 - added nlpdiving heuristic that comprises several diving heuristics using an NLP relaxation
5281Performance improvements
5282------------------------
5284- improved scaling by choosing the smallest scaler
5285- if first root lp is solved and the optimality is rejected by SCIP, there won't be an unnecessary solving of the lp
5287- several performance improvements for Pseudo-Boolean optimization, pseudo objective propagator
5288- streamlined initlp functions in cons_indicator, cons_sos1, cons_sos2 (add rows only if needed)
5289- improved time used for adding implications
5290- speed up in SCIPboolarrayExtend() in misc.c replacing a for loop with BMSmoveMemoryArray() call
5291- speed up in var.c changing some recursive calls into iterative calls and reducing the number of VARFIX event that are
5292 thrown for fixation, aggregation or multi-aggregations
5293- revised reduced cost propagator
5294- increased performance in SCIPcliqueAddVar(), adding a variable to a clique
5295- tighten primal and dual feasibility tolerances independently if they are not reached in LP solving
5298 - if probing reached the end of all variables it will restart the probing cycle correctly
5299 - improved probing by ordering the variables differently and applying the one-branch before the zero-branch
5302 - improved scaling of linear constraints, linear constraints with integral variables will now be scale with
5303 1e+06/MAX(maximal absolute coefficient, 1.0) instead of 1e+03/MAX(maximal absolute coefficient, 1.0);
5304 if all coefficients are in absolute value equal they will be scaled by that
5305 - added clique presolving for and-constraints, which checks if two operands or one operand and the resultant are in a
5306 clique and then fixes the resultant to 0 and in the former case we can delete the and-constraint too
5307 - speed up in linear constraint handler replacing aggregated variables
5308 - when all nonlinearities have been fixed and the number of nonfixed variables is 1 in cons_nonlinear/cons_quadratic/
5309 cons_bivariate, handle it by a bound change instead of adding a linear constraint
5312 - automatically turn off separation in sepa_oddcycle if it was too unsuccessful within the last calls
5313 - use faster Dijkstra variants in sepa_oddcycle
5314 - improved tcliquegraphAddImplicsVars() in sepa_clique.c to faster add possible variables
5315 - changed emphasis settings: knapsack disaggregation is now allowed in fast presolving, CG-MIP separator disabled in
5316 aggressive separation
5319 - improved lp-, mps-, opb-reading time
5320 - speed up mps reader asking parameters only once
5323 - added parameters mincoveredrel and mincoveredabs to heur_undercover to only run if problem is sufficiently nonlinear
5324 - improved intdiving heuristic by activating backtracking to a different fixing value
5325 - heur_undercover treats indicator constraints as nonlinear and fixes the binary variable for linearization
5327Examples and applications
5328-------------------------
5330- new examples for scheduling and usage of the callable library with nonlinear problems
5331- the error messages are not handled via the message handler anymore; per default the error message a written to stderr
5336- introduced basic inclusion and creation methods to simplify usage of the SCIP library
5337- allowed to start diving mode even if LP is not flushed, not solved, or not solved to optimality
5338- changed the message handler system within SCIP heavily such that it is thread save
5339- the resolve propagation methods for the constraint handler and propagator getting a new parameter called relaxedbd;
5340 explaining/resolving this relaxed bound is sufficient
5341- default integer comparer SCIPsortCompInt() (see pub_misc.h)
5344 - SoPlex LPI supports setting of `SCIP_LPPAR_DUALFEASTOL` when using SoPlex version 1.6.0.5 and higher.
5347 - Forbid problem modifications in `SCIP_STAGE_{INIT,EXIT}PRESOLVE` (see pre-conditions for corresponding methods in scip.h).
5350 - New macro SCIPdebugPrintCons() to print constraint only if `SCIP_DEBUG` flag is set.
5351 - all objscip *.h file now use the default SCIP interface macros (this should avoid errors when changing the interface)
5353### New and changed callbacks
5355- Constraint Handler:
5356 - Added a propagation timing parameter `proptiming` to SCIP_DECL_CONSPROP(), giving the current timing at which
5357 this method is called (also to the corresponding c++ wrapper classes).
5358 - New optional callback methods in constraint handlers: `SCIP_DECL_CONSGETVARS` and `SCIP_DECL_CONSGETNVARS`.
5359 These callbacks, if implemented, should return an array of all variables and the number of all variables used
5360 by the given constraint, respectively. (This method might, e.g., be called by a presolver)
5362- NLP Solver Interface:
5363 - New NLPI callback SCIP_DECL_NLPISETMESSAGEHDLR() to set message handler in NLP solver interfaces.
5366 - Added a propagation timing parameter `proptiming` to SCIP_DECL_PROPEXEC(), giving the current timing at which this method is
5367 called (also to the corresponding c++ wrapper classes).
5370 - added `basic` inclusion methods which have only fundamental data of the plug-ins as arguments; added setter functions
5371 for all non-fundamental callbacks of the plug-ins; the plug-in types with basic inclusion functions are:
5372 readers, constraint handlers, conflict handlers, presolvers, propagators, heuristics, separators, relaxation handlers,
5373 branching rules, node selectors and pricers; these methods should make the usage easier, sparing out optional callbacks and
5374 parameters: e.g., SCIPincludeConshdlrBasic();
5375 - To extend the basic functionalities, there are setter method to add
5376 optional callbacks. For example SCIPsetConshdlrParse(), SCIPsetPropCopy() or SCIPsetHeurInitsol().
5378- Constraint Handlers:
5379 - Added basic creation methods for all constraints types, e.g., SCIPcreateConsBasicLinear(); these methods should make the usage easier,
5380 sparing out optional callbacks and parameters.
5382### Deleted and changed API methods
5384- SCIPcomputeCoverUndercover() now has an additional parameter coverbd
5385- tcliqueMaxClique has an additional parameter to store the number of used branch-and-bound nodes
5386- the code in `src/dijkstra` and `src/xml` has been changed to (increasingly) conform to the SCIP coding style;
5387 all function (and variable) names have been changed (do not contain `_` anymore).
5388- renamed SCIPstairmap*Core() to SCIPstairmap*Stair()
5391 - Added parameter `relaxedbds` to conflict handler callback method SCIP_DECL_CONFLICTEXEC(). This array contains
5392 bounds which are sufficient to create a valid conflict
5394- Constraint Handler:
5395 - Added a parameter `restart` to the SCIP_DECL_CONSEXITSOL() callback method, indicating whether this call was
5396 triggered by a restart.
5397 - Added a parameter `relaxedbd` to SCIP_DECL_CONSRESPROP() callback method. If explaining a given bound change
5398 (index), it is sufficient to explain the reason for reaching the `relaxedbd` value, see above
5399 - Removed parameters `isunbounded`, `isinfeasible` and `result` from SCIP_DECL_CONSINITPRE() and SCIP_DECL_CONSEXITPRE()
5400 callback methods. It is not allowed to determine unboundedness or infeasibility in these callbacks, anymore.
5401 - added a `SCIP_CONS*` parameter to SCIPcreateConsDisjunction() which can represent the linear relaxation of the whole
5402 disjunction constraint as a conjunction constraint, or `NULL`
5403 - remove problematic function cons_indicator:SCIPsetSlackVarIndicator()
5404 - Renamed SCIPgetCountedSparseSolutions() to SCIPgetCountedSparseSols() in cons_countsols.{c,h}.
5407 - Changed the counting system within SCIP heavily. New method for `SCIP_SPARSESOL` usage, SCIPsparseSolCreate(),
5408 SCIPsparseSolFree(), SCIPsparseSolGetVars(), SCIPsparseSolGetNVars(), SCIPsparseSolGetLbs(), SCIPsparseSolGetUbs()
5409 in (pub_)misc.{c,h}.
5411- Cuts and Separation:
5412 - removed `targetscip` parameter from SCIPconvertCutsToConss(), now this function can only convert cuts on one instance,
5413 otherwise use SCIPcopyCuts()
5414 - added `ncutsadded` parameter to SCIPcopyCuts() to be able to store the number of copied/converted cuts
5415 - New functions SCIPcreateEmptyRowCons(), SCIPcreateEmptyRowSepa(), SCIPcreateRowCons(), and SCIPcreateRowSepa() that allow
5416 to set the originating constraint handler or separator of a row respectively; this is, for instance, needed for statistics
5417 on the number of applied cuts. If rows are created outside a constraint handler or separator use SCIPcreateRowUnspec() and
5418 SCIPcreateEmptyRowUnspec(). The use of SCIPcreateEmptyRow() and SCIPcreateRow() is deprecated.
5419 - New functions SCIProwGetOrigintype(), SCIProwGetOriginCons(), and SCIProwGetOriginSepa() to obtain the originator
5423 - new parameter numerics/lpfeastol for primal feasibility tolerance used in LP solver
5424 - SCIPcomputeLPRelIntPoint() takes two new arguments giving a time and iteration limit
5425 - SCIPcolGetStrongbranchLPAge(), SCIPgetVarStrongbranchLPAge(), SCIPgetNLPs(), SCIPgetNPrimalLPs(), SCIPgetNDualLPs(),
5426 SCIPgetNBarrierLPs(), SCIPgetNResolveLPs(), SCIPgetNPrimalResolveLPs(), SCIPgetNDualResolveLPs(), SCIPgetNNodeLPs(),
5427 SCIPgetNNodeInitLPs(), SCIPgetNDivingLPs(), SCIPgetNStrongbranchs(), SCIPgetNRootStrongbranchs() now return a longint
5428 instead of an integer
5430- Message Handler and Printing:
5431 - New callback method SCIP_DECL_MESSAGEHDLRFREE() which is called when the message handler is freed.
5432 - The old callback method SCIP_DECL_MESSAGEERROR() was replaced by the callback method SCIP_DECL_ERRORPRINTING().
5433 - the follwing methods additionally need the SCIP pointer as parameter to make the output thread save:
5434 SCIPprintVersion(), SCIPsetMessagehdlr(), SCIPgetMessagehdlr() and SCIPwarningMessage()
5435 - the error printing method can be replaced using the method SCIPmessageSetErrorPrinting(); the default error message
5436 printing can be recoverd via SCIPmessageSetErrorPrintingDefault() (see pub_message.h)
5437 - Changed the message handler system within SCIP heavily such that it is thread-safe. SCIPcreateMessagehdlr() in
5438 scip.{c,h} was replaced by SCIPmessagehdlrCreate() in pub_message.h/message.c with a changed parameter list;
5439 see pub_message.h and type_message.h.
5440 - removed method SCIPcreateMesshdlr(), please use SCIPmessagehdlrCreate() (see pub_message.c)
5441 - removed method SCIPfreeMesshdlr(), please use SCIPmessagehdlrRelease() (see pub_message.c)
5442 - Error messages (SCIPerrorMessage()) are not handled via the message handler anymore; per default the error
5443 message is written to stderr.
5444 - the following methods need an additional message handler: SCIPdispLongint(), SCIPdispInt(), SCIPdispTime(), all message
5445 handler methods (see pub_message.h), SCIPhashtablePrintStatistics(), SCIPhashmapPrintStatistics(), SCIPlpiCreate()
5446 - SCIPprintCons() does not print termination symbol `;\n` anymore; if wanted, use SCIPinfoMessage() to print `;\n` manually
5447 - remove SCIPcolPrint() and SCIProwPrint(), please use SCIPprintCol() SCIPprintRow() see scip.h
5448 - method SCIPprintError() does not need the file stream anymore. The error is written via the error message callback.
5450- Nonlinear expressions, relaxation, and solver interface:
5451 - Method SCIPexprtreeRemoveFixedVars() is not public anymore.
5452 - Renamed SCIPmarkNonlinearitiesPresent() to SCIPenableNLP()
5453 - Renamed SCIPhasNonlinearitiesPresent() to SCIPisNLPEnabled().
5454 - removed SCIPmarkContinuousNonlinearitiesPresent(),
5455 renamed SCIPhasContinuousNonlinearitiesPresent() to SCIPhasNLPContinuousNonlinearity() and allow call only during
5456 initsolve and solve,
5459 - Replaced SCIPparamSet*() by SCIPchg*Param()
5460 + replaced SCIPparamSetBool() by SCIPchgBoolParam()
5461 + replaced SCIPparamSetInt() by SCIPchgIntParam()
5462 + replaced SCIPparamSetLongint() by SCIPchgLongintParam()
5463 + replaced SCIPparamSetReal() by SCIPchgRealParam()
5464 + replaced SCIPparamSetChar() by SCIPchgCharParam()
5465 + replaced SCIPparamSetString() by SCIPchgStringParam()
5468 - Removed parameters `isunbounded`, `isinfeasible` and `result` from SCIP_DECL_PRESOLINITPRE() and
5469 SCIP_DECL_PRESOLSEXITPRE(). It is not allowed to determine unboundedness or infeasibility in these callbacks, anymore.
5472 - changed parameters of function SCIPpropagateCutoffboundVar() in prop_pseudoobj.{c,h}
5473 - Added a parameter `restart` to SCIP_DECL_PROPEXITSOL() callback method, indicating whether this call was triggered
5475 - Added a parameter `relaxedbd` to SCIP_DECL_PROPRESPROP() callback method. If explaining a given bound change
5476 (index), it is sufficient to explain the reason for reaching the `relaxedbd` value.
5477 - Removed parameters `isunbounded`, `isinfeasible` and `result` from SCIP_DECL_PROPINITPRE() and
5478 SCIP_DECL_PROPEXITPRE() callback methods. It is not allowed to determined unboundedness or infeasibility in
5479 these callbacks, anymore.
5482 - The methods SCIPsortedvecInsert*() have an additional parameter which can be used to receive the position where
5483 the new element was inserted, if this is not of interest a `NULL` pointer can be given
5484 - new parameter in SCIPcopyPlugins() to indicate whether the message handler from the source SCIP should be passed to the
5485 target SCIP (only the pointer is copied and the usage counter of the message handler is increased)
5486 - New parameter in SCIPcopy() to indicate whether the message handler from the source SCIP
5487 should be passed to the target SCIP (only the pointer is copied and the usage counter of the message handler is
5488 increased). In multi theaded enviroment this parameter needs to be set to FALSE.
5491 - rename SCIPvarGetBestBound() to SCIPvarGetBestBoundLocal()
5492 - rename SCIPvarGetWorstBound() to SCIPvarGetWorstBoundLocal()
5493 - Method SCIPvarGetProbvarSum() is not public anymore, use SCIPgetProbvarSum() instead.
5494 - Replaced method SCIPvarGetRootRedcost() by SCIPvarGetBestRootRedcost().
5496### New API functions
5498- setup timer to all plugins and therefore SCIP<plugin-type>GetSetupTime() methods in all pub_plugin-type.h to ask
5499 for this time (, e.g. SCIPeventhdlrGetSetupTime() in pub_event.h)
5500- new GML(Graph Modeling Language) methods SCIPgmlWriteOpening(), SCIPgmlWriteCosing(), SCIPgmlWriteArc(), SCIPgmlWriteEdge(),
5501 SCIPgmlWriteNode() that write to a given GML file
5502- new LPI method SCIPlpiGetObjsen() to query objective sense
5503- SCIPpermuteIntArray() in pub_misc.h and misc.c for permuting an integer array
5504- SCIPcalcBinomCoef() in pub_misc.h and misc.c which calculates a binomial coefficient up to 33 over 16
5505- SCIPheurPassSolAddSol() in heur_trysol.c; solution which are passed via this method are just without any feasibility check
5506- SCIPgetGlobalPseudoObjval() which returns the global pseudo objective value which is all variables
5507 set to their best (w.r.t. the objective function) global bound
5508- SCIPhashGetKeyStandard() which returns the element itself as the key, SCIPhashKeyEqPtr(),
5509 SCIPhashKeyValPtr() which do the hash-comparison/-conversion on a pointer in pub_misc.h
5510- SCIPhashtableClear() which removes all elements of a hash table
5511- SCIPisUpdateUnreliable() to check whether an iteratively updated value should be recomputed from scratch
5512 (e.g., for activities; uses new parameter `misc/num_recompfac`)
5513- SCIPisHugeValue() to check whether a value is huge and should be handled separately from other values
5514 (e.g., in activity computations) and SCIPgetHugeValue() to get the smallest value counting as huge
5515- SCIPfixParam() and SCIPunfixParam() to fix and unfix a parameter, respectively;
5516 the fixing status of a parameter can be requested by SCIPparamIsFixed();
5517- SCIPsetBasePointClosecuts() to set the base point for close cut separation
5518- SCIPchgCutoffboundDive() to change the cutoffbound in diving mode
5519- SCIPupdateCutoffbound() which can be used to pass a cutoff bound
5522 - SCIPpropIsPresolDelayed() which return if a propagator is delay during presolving
5523 - Added method SCIPisPresolveFinished() which returns whether the presolving process would be stopped after the
5524 current presolving round, given no further reductions will be found, can be used to ensure that a presolver is called very late
5527 - added forgotten implementation of SCIPfreeMemorySize(), SCIPfreeMemorySizeNull() in scip.h and BMSfreeMemorySize(),
5528 BMSfreeMemorySizeNull() in memory.h
5529 - SCIPmemccpy() in pub_misc.h and misc.c which copies either a specified number of charcters of a source
5530 string to a destination string or until it hits a stoping character
5531 - BMSmoveMemory(), BMSmoveMemoryArray(), BMSmoveMemorySize() and corresponding BMSmoveMemory_call() in
5532 memory.{h,c} too move memory elements
5535 - SCIPisConflictAnalysisApplicable() which return FALSE is the conflict will not runs; can be used
5536 to avoid unnecessary initialization of the conflict analysis
5537 - SCIPaddConflictRelaxedLb(), SCIPaddConflictRelaxedUb() and SCIPaddConflictRelaxedBd(); these methods
5538 can be used to give for a bound change which is part of an explanation a relaxed bound; this means the relaxed bound
5539 is already efficient to be part of a valid explanation
5540 - SCIPisConflictVarUsed() returns TRUE if the given bound change is already part of the conflict set;
5541 that is the bound change is redundant;
5542 - SCIPgetConflictVarLb() and SCIPgetConflictVarUb() returning the lower/upper bound of the given
5543 variable within the current active conflict set
5546 - SCIPvarsGetProbvar() in pub_var.h and var.c, which returns for a given array of variables the active, fixed
5547 or multiaggregated representation
5548 - SCIPgetActiveVars() in scip.{h,c}, which returns for a given array of variables the active counterparts
5549 - SCIPgetNObjVars() which returns the number of variables which have a non-zero objective coefficient
5550 - SCIPenableVarHistory() and SCIPdisableVarHistory() which can be used to turn off and on the collection
5551 of variables statistics which is used for example for branching
5552 - SCIPbranchVarHole() which branches a variable w.r.t. a given domain hole
5553 - SCIPvarGetAggregatedObj() which computes for a (not active) variable the corresponding objective value
5554 - SCIPsolIsOriginal() that returns whether a solution is defined on the original variables
5555 - SCIPgetVarImplRedcost() which returns the implied reduced costs
5556 - SCIPvarGetBestRootSol(), SCIPvarGetBestRootRedcost(), SCIPvarGetBestRootLPObjval() which return the best
5557 combination for a variable w.r.t. root solution value, root LP objective value and root reduced cost
5558 - SCIPhaveVarsCommonClique() in scip.{h,c}, to check for common clique information on two given variables
5559 - added basic creation methods SCIPcreateVarBasic() and SCIPcreateProbBasic() and setter functions for
5560 non-fundamental callbacks of variables and problems.
5561 - added new methods SCIPvarGetBestBoundGlobal() and SCIPvarGetWorstBoundGlobal().
5563- Constraint Handler:
5564 - added public wrapper functions for calling constraint handler callback methods for a single constraint:
5565 SCIPactiveCons(), SCIPdeactiveCons(), SCIPinitlpCons(), SCIPsepalpCons(), SCIPsepasolCons(), SCIPpropCons(),
5566 SCIPrespropCons(), SCIPenfopsCons(), SCIPenfolpCons()
5567 - added basic creation methods for all constraint handlers
5568 - SCIPchgCapacityKnapsack() which can be used to change the capacity of a knapsack constraint
5569 - SCIPconsIsAdded() which returns whether a constraint was already to a SCIP instance
5570 - SCIPconshdlrGetNCutsApplied() in pub_cons.h to get the number of cuts applied to the lp
5571 - SCIPconshdlrIncNAppliedCuts() in cons.h to increase the number of applied cuts (used by sepastore.c)
5572 - SCIPchgVarName() and SCIPchgConsName() which can be used to change name of variables and
5573 constraints in problem creation stage
5574 - New methods SCIPgetConsVars() and SCIPgetConsNVars() which return for a given constraint the involved variables and
5575 the number of variables if the corresponding constraint supports this (optional) callbacks
5576 (corresponding callbacks need to be implemented, see above)
5579 - SCIPmessagehdlrCapture() which captures a given message handler (increases number of uses)
5580 - SCIPmessagehdlrRelease() which releases and possibly frees a given message handler (decreases number of uses)
5581 - SCIPsetMessagehdlrLogfile() which can be used to write into a log file
5582 - SCIPsetMessagehdlrQuiet() which can be used to turn the screen output on and off
5584### Command line interface
5586- in the interactive shell, parameters can be fixed and unfixed with `fix` (instead of `set`), e.g., `fix heuristics rens freq TRUE`;
5587- new shell command `change minuc` to minimize the number of unsatisfied constraints
5589### Interfaces to external software
5591- beta-version of a MATLAB interface can be found under interfaces/matlab
5592- beta-version of a AMPL interface can be found under interfaces/ampl
5594### Changed parameters
5596- `branching/fullstrong/reevalage` changed from an integer to a longint parameter
5598- Removed parameters:
5599 - `separating/closecuts/separootonly`
5600 - `constraints/quadratic/defaultbound`
5601 - `separating/cgmip/nodelimit`
5605- `constraints/%s/timingmask` for changing the timingmask for calling the propagtion method of all constraint plugins
5606- `constraints/and/dualpresolving` by default set to TRUE, enabling dual-presolving on and-constraints
5607- `constraints/indicator/{sepacouplingcuts,sepacouplinglocal}` to enable separation of (local) cuts
5608- `constraints/indicator/{maxsepacuts,maxsepacutsroot}` to restrict the number of separated cuts
5609- `constraints/indicator/dualreductions` to enable dual presolving/propagation steps
5610- `constraints/setppc/cliquelifting`, `constraints/setppc/addvariablesascliques`,
5611 `constraints/setppc/cliqueshrinking`, first for enabling/disabling the clique lifting algorithm in cons_setppc.c,
5612 second parameter is for trying to create extra clique constraints in lifting algorithm, third parameter is for trying
5613 to decrease the number of variable in a clique constraint in the lifting algorithm
5614- `limits/totalnodes` that allows to stop at the correct node if a restart occured; therefore the new
5615 `SCIP_STATUS_TOTALNODELIMIT` is added
5616- `lp/{rootiterlim,iterlim}` to set a limit on the LP iterations spend in the initial root LP and each
5617 LP resolve, respectively
5618- `misc/transorigsols` by default set to TRUE, that switches whether SCIP tries to transfer original
5619 solutions into the transformed space (in initsol and if a heuristic adds an original solution during solving)
5620- `numerics/hugeval` that defines the smalles value counting as huge (see new method SCIPisHugeValue())
5621- `numerics/recompfac` which denotes the factor, by which the absolute of an iteratively updated value has
5622 to be decreased in order to recompute the value from scratch
5623- `presolving/convertinttobin/maxdomainsize` by default is set to `SCIP_LONGINT_MAX`, which deternmines
5624 the domainsize for which integers are converted to their binary representation
5625- `presolving/convertinttobin/onlypoweroftwo` by default is set to FALSE, that parameter allows you to
5626 only convert integer variables with a domainsize of 2^p-1 to their binary representation
5627- `presolving/convertinttobin/samelocksinbothdirections` by default is set to FALSE, that parameter allows
5628 you to convert only integer variables to their binary representation, which have the same amount of up- and downlocks
5629- `presolving/gateextraction/sorting` by default is set to 1, that parameter determines if you want to try
5630 to extract big-gates(-1) or small-gates(1) at first by ordering bigger/smaller logicor constraint up front, or use
5631 them as they are (0)
5632- `presolving/gateextraction/onlysetpart` by default is set to FALSE, that parameter allows you to
5633 only extract set-partitioning and no and-constraints
5634- `presolving/gateextraction/searchequations` by default is set to TRUE, that parameter allows you to
5635 search for logicor constraints and set-packing/-partitioning constraints with same variables
5636- `propagating/%s/timingmask` for changing the timingmask for calling the propagtion method of all propagator plugins
5637- `propagating/probing/maxdepth` to set the maximal depth until the probing propagation is executed
5638- `reading/cnfreader/useobj` to state whether an artificial objective, depending on the number of clauses
5639 a variable appears in, should be used, by default set to FALSE, old default behavior of reader corresponds to TRUE
5640- `separating/cgmip/{minnodelimit,maxnodelimit}` to determine node limit.
5641- `separating/closecuts/maxlpiterfactor` for iteration limit in relative interior point computation
5642- `separating/oddcycle/maxunsucessfull` to automatically turn off separation
5643- `oncepernode` in Rounding and Simple Rounding heuristic
5647- new data structure for binary trees (`SCIP_BT` and `SCIP_BTNODE` in pub_misc.h)
5648- renamed data structure `SCIP_STAIRMAP` to `SCIP_PROFILE`
5649- added new stages `SCIP_STAGE_INITPRESOLVE`, `SCIP_STAGE_EXITPRESOLVE` and `SCIP_STAGE_FREE`; renamed `SCIP_STAGE_FREESOLVE`
5650 to `SCIP_STAGE_EXITSOLVE`
5651- Changed the counting system within SCIP heavily. `SPARSESOLUTION` was renamed to `SCIP_SPARSESOL` and moved
5652 from cons_countsols.h to struct_misc.h
5657- the check script now recognizes MIQCP and MINLP instances
5658- make test now also checks instances in wbo, cnf, osil and fzn format
5659- renamed parameter SCRDIR of `make testgams` to CLIENTTMPDIR and changed its default to `/tmp`
5666- CppAD source code is now distributed with SCIP (`src/cppad`), so that `lib/cppad` is not used anymore;
5667 the default for EXPRINT has changed from none to cppad
5672- fixed bug with strong branching with the LP status for conflict analysis
5673- fixed bug w.r.t. adding a value to the objective offset of the transformed problem
5674- fixed wrong assert in feasibility pump stage 3
5675- fixed bug in solve.c, applied bounding for the initial lp was only done if root-lp-solution was valid but another
5676 solution could also have been added
5677- primal solutions with infinite objective value are now automatically discarded
5678- all plugins that solve sub-SCIPs now do not stop the whole solution process if there has been an error
5679- fixed bug in cip reader, wrong use of SCIPstrtok()
5682 - fixed bug in shiftandpropagate w.r.t. SCIPconstructLP() which can have the side effect that variables are created
5683 - method SCIPvarGetProbvarSum() (and thus also SCIPgetProbvarSum()) returns +/-infinity if the variable resolves to a
5684 variable fixed to +/-infinity (depending on the sign of the scalar) but does not multiply with the scalar, anymore
5685 - better handling of infinite solution values for aggregated and negated variables
5686 - fixed bug that disabled multi-aggregation of two integer or implicit integer variables
5687 - fixed bug in sol.c with requesting values of transformed variables in original solution; previously this had only
5688 been handled in SCIPgetSolVal(), now the handling has been moved to SCIPsolGetVal()
5689 - fixed several bugs writing an mps file in the reader_mps.c, e.g. writing fixed variables which are not (yet) removed
5690 and writing integer variables even with an objective value of 0, if they only exist in non-linear constraints
5693 - fixed minor bugs with respect to counting generated and lifted cuts in sepa_oddcycle
5694 - fixed bug in sepa_clique.c, could not handle only empty cliques, that were not removed
5697 - fixed potential bugs in shiftandpropagate heuristic concerning the transformation update of a variable with free status
5698 - fixed bug in heur_zirounding with computation of up/downslacks
5699 - fixed bug in mutation heuristic with unnecessary aborts due to a wrong memory limit
5700 - fixed potential bug in fix-and-infer heuristic with variables being fixed to infinite value
5701 - fixed bug in diving heuristics with variables being fixed to values outside their domain
5702 - fixed bug in simple rounding heuristic with column generation for variables with strictly positive lower bound
5703 - made Octane heuristic numerically more stable to avoid asserts being caused by cancellation
5704 - fixed bug in mutation heuristic with variables being fixed to infinite values
5705 - do not run heur_shiftandpropagate if there is no LP
5708 - fixed bug in Cplex LPI: after running simplex, solisbasic flag was always true, which might be wrong if Cplex hit a
5710 - fixed bug in SCIP probing mode with cleared LPI state but solved LP
5711 - fixed assert with `LPI=none` (need to count rows/cols in lpi_none)
5712 - fixed bug in SoPlex LPI where objective sense was not correct after reading LP from file in SCIPlpiReadLP()
5715 - fixed bug in scip.c adding a constraint in SCIPgetConsCopy() to the constraint hashmap
5716 - fixed bug in cons_linear w.r.t recalculation of unreliable activities
5717 - fixed bug in cons_linear concerning huge activity values: besides infinite contributions, we now also treat huge
5718 contributions separately, count their occurences in a constraint and provide a relaxed activity value
5719 - fixed bug in cons_xor.c parsing a constraint
5720 - fixed count of propagations in cons_indicator and only try to propagate if variables are not yet fixed
5721 - fixed some bugs in cons_disjunction.c (wrong assert, forgotten deletion of constraint, wrong SCIPreleaseCons() call)
5726- first release of GCG, a generic branch-cut-and-price solver built on top of SCIP
5727- first release of UG, a framework for solving mixed integer programs, mixed integer
5728 nonlinear programs and constraint integer programs in parallel
5730- renamed ZIB Optimization Suite to SCIP Optimization Suite
5732@page RN2_1 Release notes for SCIP 2.1
5734@section RN212 SCIP 2.1.2
5735*************************
5737Performance improvements
5738------------------------
5740- fixed performance issue in debug mode, where SCIPvarGetLPSol_rec() calculated a value to often, which in the end lead
5741 to exponential growth in running time
5742- force cuts from linearizations of convex constraint in NLP relax solution into LP, thus allowing faster proving of
5743 optimality for convex NLPs
5748- fixed bug in varAddTransitiveImplic() in var.c, when adding implications on special aggregated, namely negated, variables
5749- fixed issue if a primal solution leads to a cutoff of the current focus node
5750- fix compilation issues with zlib 1.2.6
5751- fixed bug in SCIPsolveKnapsackExactly(), trying to allocate too much memory which led to an overflow and later to a segmentation fault
5752- fixed bug in sepa_rapidlearning, carrying on the optimization process, when already solved
5755 - fixed bug in heur_undercover.c, where a variable with fixed bounds but not of status `SCIP_VARSTATUS_FIXED` was wrongly handled
5756 - fixed bug in heur_oneopt.c which forgot to check LP rows if local rows are present
5759 - fixed bug in SCIPsolveKnapsackExactly()
5760 - fixed bug in cons_quadratic where bounds on activity of quadratic term were not always invalidated when quadratic variables were removed
5761 - fixed bug in cons.c, where after a restart the arrays for all initial constraints were corrected in the initsol process
5762 instead of the initpre process, this was to late because you might change the status in presolving which lead to an assert()
5763 - fixed bug in NLP representation of abspower constraints handling (x+a)^2 with nonzero a
5764 - fixed bug parsing an and-constraint in cip format
5765 - fixed bug in cons_setppc, did not handle new constraints with inactive variables
5766 - fixed bug in cons_xor.c which did not copy the artificial integer variable (used for the lp relaxation)
5768@section RN211 SCIP 2.1.1
5769*************************
5774- the pseudo objective propagator can be forced to propagate if active pricers are present; this can be done
5775 if for all (known or unknown) variables follows that: they have positive (negative) objective coefficient
5776 and the global lower (upper) bound is zero.
5778Performance improvements
5779------------------------
5781- improvements in undercover heuristic
5782- improve SCIPintervalSolveBivariateQuadExpressionAllScalar() for ax=0 case if x has 0 in the interval for the linear coef.
5783- better domain propagation for quadratic constraints that consist of `non-overlapping` bilinear terms only
5784- ensure that a fixing of a variable in an abspower constraint is propagated to a fixing of the other variable
5785- improvements in undercover heuristic, e.g., bound disjunction constraints are considered when setting up the covering problem
5790### Changed parameters
5792- changed parameter `propagating/pseudoobj/maxcands` to `propagating/pseudoobj/minuseless` (see prop_pseudoobj.c)
5793 due to revision of the pseudo objective propagator
5797- added parameters `heuristics/undercover/coverbd` and `heuristics/undercover/fixingorder`
5802- fixed numeric issue in aggregations
5803- fixed pseudo cost computation
5804- fixed bug with setting type of slack variables to be implicitly integral
5805- fixed bug when copying problem data in c++ case returned with the result `SCIP_DIDNOTRUN`
5806- fixed computation of counter which state the changes since the last call of a presolver
5807- fixed handling of unbounded solutions, including double-checking their feasibility and that the primal ray is a
5808 valid unboundedness proof and reoptimizing the LP with modified settings if the solution is not feasible
5809- fixed compilation issues with negate() function in intervalarith.c on exotic platforms
5810- fixed bug in SCIPsortedvecDelPos...() templates
5811- pseudo objective propagator does not propagate it active pricers are present
5812- fixed bug in heur_shiftandpropagate.c concerning the treatment of unbounded variables
5813- workaround for trying to add variable bounds with to small coefficients
5815- Reading and Writing:
5816 - gams writer now also substitutes $-sign from variable/equation names
5817 - fixed bug in reader_mps.c: INTEND marker is now also written, if COLUMNS section ends with non-continous variables
5818 - fixed bug in flatzinc reader w.r.t. boolean expressions
5821 - fixed constraint flags evaluation within the ZIMPL reader (reader_zpl.c)
5822 - fixed bug in SCIPmakeIndicatorFeasible() in cons_indicator.c
5823 - fixed bug with conflict clause modification in cons_indicator
5824 - fixed bug in cons_bounddisjunction with uninitialized return values
5825 - fixed bug in cons_orbitope with calling conflict analysis
5826 - fixed bug in nlpi_oracle w.r.t. changing linear coefs in a NLP constraint
5828@section RN210 SCIP 2.1.0
5829*************************
5834- New original solution storage capability, which allows transfering solutions between SCIP runs
5835- SCIP-CPX is now threadsafe
5836- comparison of solutions now also works for original solutions
5837- can now compute the relative interior point of the current LP
5838- interval arithmetics for power, log, exp, bivariate quadratic expressions should be rounding safe now
5839- LP iterations in resolving calls can now be limited w.r.t. the average number of LP iterations in previous calls
5840 (after the root node); this is currently only done for the initial LP solve at a node and the corresponding parameter
5841 resolveiterfac is set to -1 (no limit) per default
5842- it is now possible in `SCIP_STAGE_TRANSFORMED` to call SCIPaddVarLocks() (i.e. to lock variables in initialization methods)
5843- changed computation of optimality gap which is now done in the same way as described in the MIPLIB 2010 paper: the gap
5844 is 0, if primalbound (pb) and dualbound (db) are equal (within tolerances), it is infinity if pb and db have opposite
5845 signs and (this changed), if both have the same sign, the difference between pb and db is devided by the minimum of
5846 the absolute values of pb and db (instead of always the dual bound)
5847- functionality to use the bound flipping ratio test of SoPlex is available (requires at least version 1.5.0.7)
5848- there exists now a solution candidate store for the original problem; during transformation these solutions are tried;
5849 during free the transformed problem the best feasible solution of the transformed problem are copied to the solution
5850 candidate store of the original problem; this useful if you solve several problems iteratively, solutions get now
5851 carried over automatically.
5852- reworked concept of lazy bounds: they can now also be used for problems where constraints and objective together
5853 ensure the bounds; to allow this also for diving heuristics that might change the objective and thus destroy this
5854 property, lazy bounds are explicitly put into the LP during diving and removed afterwards
5855- `SCIP_HASHMAP` now works also without block memory
5856- The variable deletion event is now a variable specific event and not global, anymore.
5857- All timing flags are now defined type_timing.h.
5858- all C template files are now called <plugintype>_xyz.{c,h} instead of <plugintype>_xxx.{c,h}
5860- Separators and Cuts:
5861 - reorganized computation of scores in cut filtering: instead of the computation at the time of addition, scores are now
5862 only computed w.r.t. the current LP solution and when cut filtering is performed; one can now fill the cut storage
5863 with cuts that were separated for different solutions
5864 - New separator for close cuts and a new function to compute relative interior points of the LP
5865 - added first version of sepa_closecuts.{c,h} to separate cuts w.r.t. a point that is closer to the integral polyhedron
5868 - implement possibility to force a restart in cons_indicator if enough indicator variables have been fixed
5869 - the xor constraint handler can now parse its constraints
5870 - the bounddisjunction constraint handler can now parse its constraints
5871 - the knapsack, setppc and soc constraint handler can now parse their constraints
5872 - the varbound constraint handler can now parse its constraints
5873 - added beta version of variable deletion: for branch-and-price application, variables can now be completely deleted
5874 from the problem; variables that are deletable have to be marked with SCIPvarMarkDeletable(), constraint handlers can
5875 implement the new `SCIP_DECL_DELVARS` callback that should remove variables from the constraints; at the moment, only
5876 the linear, the setppc and the knapsack constraint handler support this callback; furthermore, when using this
5877 feature, all used plugins have to capture and release variables they store in their data, this is currently only done
5878 for the aforementioned constraint handlers as well as the and, the varbound and the logicor constraint handler; for
5879 more details about this feature, see the FAQ
5880 - added pseudoboolean constraint handler (cons_pseudoboolean.{c,h})
5881 - added first version of cons_disjunction.{c,h} which allows a disjunction of constraints
5882 - added constraint handler for (absolute) power constraints (cons_abspower.{c,h}) to handle equations like z = sign(x)abs(x)^n, n > 1
5885 - new heuristic vbounds which use the variables lower and upper bounds to fix variable and performs a neighborhood search
5886 - added vbound heuristic (heur_vbounds.{c,h})
5887 - added clique heuristic (heur_clique.{c,h})
5889- Reading and Writing:
5890 - added writing for wbo files
5891 - added writing for pip files (linear, quadratic, polynomial nonlinear, polynomial abspower, polynomial bivariate, and
5893 - CIP format variable characters defined, e.g. `SCIP_VARTYPE_INTEGER_CHAR`
5894 - Improved support for wbo format for weighted PBO problems, IBM's xml-solution
5895 format and pip and zimpl format for polynomial mixed-integer programs
5896 - New reader for (standard) bounds on variables
5897 - Extended reader for CIP models to handle various new constraints, including all types of linear constraints
5898 - flatzinc reader is now capable to read cumulative constraints
5899 - changed opb(/wbo) reader which now creates pseudoboolean constraints instead of linear- and and-constraints, only a
5900 non-linear objective will create and-constraints inside the reader and while reading a wbo file the topcost constraint
5902 - added clock for determine the time for reading
5903 - added reader for variable bounds (reader_bnd.{c,h})
5904 - Removed method SCIPreadSol(); call solution reading via SCIPreadProb() which calls the solution reader for .sol files.
5907 - Major extensions for nonlinear CIP, new option for n-ary branching on nonlinear variables (within pseudocost branching rule)
5908 - added BETA version of constraint handler for nonlinear constraints (cons_nonlinear.{c,h}) to handle nonlinear
5909 equations given by algebraic expressions using operands like addition, multiplication, power, exp, log, bivariate
5910 nonlinear constraints; currently no trigonometric functions
5911 - added BETA version of constraint handler for bivariate nonlinear constraints (cons_bivariate.{c,h}) to compute tight
5912 estimators for 1-convex and convex-concave bivariate nonlinear functions (given as expression tree)
5913 - the gams writer can now write nonlinear, abspower and bivariate constraints
5914 - Extended writer for GAMS and pip format to write more types of nonlinear constraints
5915 - the pip and zimpl reader now create nonlinear constraints for polynomials of degree > 2
5918 - new dual presolving methods in cons_setppc and cons_logicor
5919 - new presolving step `removeConstraintsDueToNegCliques` in locigor constraint handler which updates logicor constraints
5920 to setppc constraints if a negated clique inside this constraint exist, by default is off
5921 - new presolving step in cons_knapsack (detectRedundantVars, deleteRedundantVars) which determines redundant variables
5922 in knapsack constraint with or without using clique information
5923 - cons_logicor is now able to replace all aggregated variables in presolving by there active or negation of an active
5924 variable counterpart
5925 - prop_pseudoobj is now working in presolving as well
5926 - implement presolving in exitpre() in cons_orbitope and cons_indicator
5929 - added counter for number calls and timing for resolve propagation calls for constraint handler and propagators
5930 - Propagators are now also called in node presolving
5931 - the probing presolver presol_probing.{c.h} is now a propagator prop_probing.{c,h}, all corresponding parameters moved as well
5932 - the redcost separator sepa_redcost.{c.h} is now a propagator prop_redcost.{c,h}, all corresponding parameters moved as well
5933 - outsourced propAndSolve() method in solve.c which calls domain propagation and solving of the lp and relaxation
5936 - solutions which are given by the user from the outside are now marked by `#` in the output
5937 - the `Solving Time` is now spitted into presolving, solving and reading time
5938 - Presolvers section has new column `AddCons` which states the number of added constraint
5939 - Constraints section has new column named \#ResProp which show the number of resolve propagation calls of certain
5941 - Constraint Timing section has a new column \#ResProp which states the time spend in resolve propagation method of the
5943 - improved output of propagators in display statistics
5944 - new section `Propagator Timing` which shows the time spend in different callbacks of the propagator
5945 - rearranged first two columns of Propagators section; \#Propagate and \#ResProp stating the number of call for
5946 propagation and resolve propagation; the Time column is moved into the new section Propagator Timings
5947 - Constraints section has new column named `MaxNumber` which the maximum number of active constraint of a certain
5949 - added two columns `Time-0-It` and `Calls-0-It` in the LP section which states the number of LP call and time spend for
5950 solving LPs with zero iterations (only refactorization)
5951 - The display of statistics for presolvers, propagators, constraints and LP solving has changed.
5953Performance improvements
5954------------------------
5956- Reorganized filtering process of separation storage (allows adding cuts for different solutions)
5957- Improved presolving for various constraint handlers
5958- Improved propagation methods for variable bound constraints
5959- Improved performance for quadratic constraints
5960- performance improvements in prop_vbounds
5961- child selection rules now get also applied when the relaxation value is equal to the bound changed in branching
5962- added dual reduction to cons_cumulative.c
5963- for continuous variables, the pseudo costs update and the pscost branching rule now use the same strategies for
5964 updating the pseudo costs and estimating the improvement in the LP bound
5965- only perform probing if the variables are locked
5966- performance and memory consumption improvements in xmlparse.c
5967- Improved knapsack cover cuts
5968- avoid very long separation times of LEWIs in cons_knapsack for very large minimal covers
5969- used SCIPallocMemoryArray() instead of SCIPallocBlockMemoryArray() which leads to fewer memory consumption in
5970 getLiftingSequence() in cons_knapsack, also improved cache use bei using an extra array instead blockmemory chunks
5971- switched FASTMIP from 1 to 2 for CPLEX and changed default pricing rule back to steepest edge pricing instead of
5972 quickstart steepest edge pricing
5973- made sorting method more robust
5974- LNS heuristics now use SCIPcopy() by default
5975- considering inactive variables in undercover heuristic; limiting effort for solving covering problem
5976- if during probing mode the LP relaxation is solved from scratch, e.g., when calling the shiftandpropagate heuristic
5977 before root node solving, then we clear the resulting LP state, since it might be a bad starting basis for the next
5978 solve of the LP relaxation (controlled by new parameter `lp/clearinitialprobinglp`)
5979- included LP simplifier into SoPlex LP interface, applied when solving from scratch (lpi_spx.cpp)
5980- new presolving steps in varbound constraint handler, tightening bounds, coefficients, sides and pairwise presolving
5986 - The emphasis setting types now distinguish between plugin-type specific parameter settings (default, aggressive, fast, off),
5987 which are changed by SCIPsetHeuristics/Presolving/Separating(), and global emphasis settings (default, cpsolver, easycip,
5988 feasibility, hardlp, optimality, counter), which can be set using SCIPsetEmphasis().
5990### New and changed callbacks
5992- added propagator timings `SCIP_PROPTIMING_BEFORELP`, `SCIP_PROPTIMING_DURINGLPLOOP` and `SCIP_PROPTIMING_AFTERLPLOOP` for
5993 all propagation callbacks (see propagators and constraint handlers) which lead to calling the propagation methods of a
5994 propagator before the lp is solved, during the lp loop and after the lp solving loop
5997 - Added parameter `separate` to conflict handler callback method SCIP_DECL_CONFLICTEXEC() that defines whether the conflict
5998 constraint should be separated or not.
6000- Constraint Handler:
6001 - The new constraint handler callback SCIP_DECL_CONSDELVARS() is called after variables were marked for deletion.
6002 This method is optional and only of interest if you are using SCIP as a branch-and-price framework. That means,
6003 you are generating new variables during the search. If you are not doing that just define the function pointer
6005 If this method gets implemented you should iterate over all constraints of the constraint handler and delete all
6006 variables that were marked for deletion by SCIPdelVar().
6008- NLP Solver Interface:
6009 - The callbacks SCIP_DECL_NLPIGETSOLUTION() and SCIP_DECL_NLPISETINITIALGUESS() got new parameters to get/set values of
6011 - The callback SCIP_DECL_NLPICOPY() now passes the block memory of the target SCIP as an additional parameter.
6014 - New parameters `isunbounded` and `isinfeasible` for presolving initialization (SCIP_DECL_CONSINITPRE(),
6015 SCIP_DECL_PRESOLINITPRE(), SCIP_DECL_PROPINITPRE()) and presolving deinitialization (SCIP_DECL_CONSEXITPRE(),
6016 SCIP_DECL_PRESOLEXITPRE(), SCIP_DECL_PROPEXITPRE()) callbacks of presolvers,
6017 constraint handlers and propagators, telling the callback whether the problem was already declared to be
6018 unbounded or infeasible. This allows to avoid expensive steps in these methods in case the problem is already
6021 Note, that the C++ methods
6022 - scip::ObjConshdlr::scip_presol() corresponding to SCIP_DECL_CONSPRESOL()
6023 - scip::ObjConshdlr::scip_initpre() corresponding to SCIP_DECL_CONSINITPRE()
6024 - scip::ObjPresol::scip_initpre() corresponding to SCIP_DECL_PRESOLINITPRE()
6025 - scip::ObjProp::scip_initpre() corresponding to SCIP_DECL_PROPINITPRE()
6026 - scip::ObjConshdlr::scip_exitpre() corresponding to SCIP_DECL_CONSEXITPRE()
6027 - scip::ObjPresol::scip_exitpre() corresponding to SCIP_DECL_PRESOLEXITPRE()
6028 - scip::ObjProp::scip_exitpre() corresponding to and SCIP_DECL_PROPEXITPRE()
6029 are virtual functions. That means, if you are not adding the new parameters, your code will still compile, but these methods are not executed.
6030 - Propagators are now also called in during presolving, this is supported by the new callback methods SCIP_DECL_PROPINITPRE(),
6031 SCIP_DECL_PROPEXITPRE(), and SCIP_DECL_PROPPRESOL().
6032 - The new parameters `nnewaddconss` and `naddconss` were added to the constraint handler callback method SCIP_DECL_CONSPRESOL()
6033 and the presolver callback method SCIP_DECL_PRESOLEXEC(). These parameters were also added to corresponding C++ wrapper
6034 class methods (scip_presol() in objconshdlr.h and scip_exec() in objpresol.h)
6037 - The callback SCIP_DECL_PROBCOPY() got a new parameter `global` to indicate whether the global problem or a local version is copied.
6039### Deleted and changed API methods
6041- implemented SCIPlpiGetPrimalRay() in SoPlex interface that has become available with SoPlex version 1.5.0.2
6042- allowed calling SCIPgetRowSolActivity() in `SCIP_STAGE_SOLVED`, since LP is still available
6043- various extensions and modifications for expressions and expression trees (too much to state here)
6044- The result value `SCIP_NEWROUND` has been added, it allows a separator/constraint handler to start a new separation round
6045 (without previous calls to other separators/conshdlrs).
6046- SCIPcalcNodeselPriority() got a new parameter `branchdir`, which defines the type of branching that was performed: upwards, downwards, or fixed.
6048- Constraint Handlers:
6049 - Method SCIPincludeQuadconsUpgrade() of quadratic constraint handler got new parameter `active` to indicate whether the upgrading method is active by default.
6050 - Method SCIPseparateRelaxedKnapsack() in knapsack constraint handler got new parameter `cutoff`, which is a pointer to store whether a cutoff was found.
6052- Nonlinear expressions, relaxation, and solver interface:
6053 - SCIPcreateNLPSol() now creates a `SCIP_SOL` that is linked to the solution of the current NLP relaxation
6054 - Various types and functions dealing with polynomial expressions have been renamed to use the proper terms `monomial` and
6055 `polynomial` in nonlinear expressions (nlpi/∗expr*); results in many renamings of types, structs and methods.
6056 - The methods SCIPnlpGetObjective(), SCIPnlpGetSolVals(), and SCIPnlpGetVarSolVal() have been removed, use SCIPgetNLPObjval(),
6057 SCIPvarGetNLPSol() and SCIPcreateNLPSol() to retrieve NLP solution values instead.
6058 SCIPcreateNLPSol() now returns an error if NLP or NLP solution is not available
6059 - Removed methods SCIPmarkRequireNLP() and SCIPisNLPRequired(), because the NLP is now always constructed if nonlinearities
6061 - SCIPgetNLP() has been removed and NLP-methods from pub_nlp.h have been moved to scip.h, which resulted in some renamings, too.
6062 - renamed SCIPexprtreeEvalSol() to SCIPevalExprtreeSol() and now located in scip.h.
6063 - renamed SCIPexprtreeEvalIntLocalBounds() to SCIPevalExprtreeLocalBounds() and now located in scip.h.
6064 - renamed SCIPexprtreeEvalIntGlobalBounds() to SCIPevalExprtreeGlobalBounds() and now located in scip.h.
6065 - The functions SCIPnlpiGetSolution() and SCIPnlpiSetInitialGuess() got additional arguments to get/set dual values.
6066 - The method SCIPgetNLPI() got a new parameter `nlpiproblem`, which is a pointer to store the NLP solver interface problem.
6069 - SCIPincludeProp() got additional parameters to set the timing mask of the propagator and the new callbacks and parameters
6070 related to calling the propagator in presolving.
6071 - SCIPincludeConshdlr() got additional parameters to set the variable deletion callback function and the timing mask for
6073 - removed parameters timelimit and memorylimit from SCIPapplyRens()
6074 - The parameters `timelimit` and `memorylimit` were removed from SCIPapplyRens().
6077 - The method SCIPcopyProb() got a new parameter `global` to indicate whether the global problem or a local version is copied.
6079- Writing and Parsing Constraints:
6080 - The methods SCIPwriteVarName(), SCIPwriteVarsList(), and SCIPwriteVarsLinearsum() got a new boolean parameter `type`
6081 that indicates whether the variable type should be written or not.
6082 - The methods SCIPparseVarName() and SCIPparseVarsList() got a new output parameter `endptr` that is filled with the position
6083 where the parsing stopped.
6084 - The method SCIPwriteVarsList() got additionally a new parameter `delimiter` that defines the character which is used for delimitation.
6087 - SCIPmarkDoNotMultaggrVar()/SCIPvarMarkDoNotMultaggr() now allow to mark negated and aggregated variables
6088 - SCIPgetVarCopy() got a new parameter `success` that will be FALSE if method is called after problem creation stage and no hash map is
6089 given or no image for the given variable is contained in the given hash map.
6090 - SCIPchgVarType() got an extra boolean parameter to store if infeasibility is recognized while upgrading a variable from continuous
6091 type to an integer type.
6092 - SCIPdelVar() got a new parameter `deleted`, which stores whether the variable was successfully marked to be deleted.
6094### New API functions
6096- information about the quality of the solution of an LP (currently the condition number of the basis matrix) can now be:
6097 + requested from the LPI (currently only available for CPLEX): methods SCIPlpiGetRealSolQuality() and
6098 + SCIPprintLPSolutionQuality() command display lpsolquality in interactive shell display column lpcond to show
6099 + estimate on condition number, if available
6100- SCIPround() and SCIPfeasRound() to round to nearest integer
6101- SCIPsortRealRealIntInt() and corresponding sorting/inserting/deleting methods in pub_misc.h and necessary defines in misc.c
6102- SCIPsortRealIntLong(), SCIPsortPtrPtrRealInt() and corresponding sorting/inserting/deleting methods in
6103 pub_misc.h and necessary defines in misc.c
6104- SCIPcomputeLPRelIntPoint() to compute relative interior point of the current LP
6105- SCIPstartSolvingTime() and SCIPstopSolvingTime() which can be used to start or stop the solving time clock
6106- SCIPstrToRealValue() and SCIPstrCopySection() in pub_misc.h; these methods can be used to convert a string
6107 into a `SCIP_Real` value and to copy a substring.
6108- SCIPgetBinvarRepresentatives() which gets binary variables that are equal to some given binary variables,
6109 and which are either active, fixed, or multi-aggregated, or the negated variables of active, fixed, or multi-aggregated variables
6110- SCIPhasPrimalRay() and SCIPgetPrimalRayVal() that return whether a primal ray is stored and which value a
6111 given variable has in the primal ray, respectively
6112- SCIPsetConsModifiable()
6113- SCIPsetParam() which is a generic parameter setter method, independent of the parameter type
6114- SCIPpropInitpre(), SCIPpropExitpre(), SCIPpropPresol() which initializes, exists and executes the presolving phase
6115- SCIProwGetAge() to access the age of a row (pub_lp.h/lp.c)
6116- SCIPsolGetOrigObj() in pub_sol.h which returns for a solution in the original problem space the objective value
6117- SCIPretransformSol() in scip.h that allows to retransform a solution to the original space
6118- SCIPlpiClearState() to LP interfaces for clearing basis information in the LP solver
6119- SCIPgetSubscipDepth() to access the depth of the current SCIP as a copied subproblem
6120- SCIPdebugAddSolVal() and SCIPdebugGetSolVal() to add/get values to/from a debug solution
6121- SCIPsepastoreRemoveInefficaciousCuts() to remove non-efficious cuts from the separation storage
6124 - SCIPnodeGetParent() to get parent node of a node
6125 - SCIPnodesSharePath() in pub_tree.h that determines whether two nodes are on the same leaf-root path
6126 - SCIPnodesGetCommonAncestor() in pub_tree.h that finds the common ancestor node for two given nodes
6129 - SCIPgetReadingTime() which returns the time for reading in seconds
6130 - SCIPparseVarsLinearsum(), SCIPparseVarsPolynomial() and SCIPwriteVarsPolynomial() and for writing and
6131 parsing polynomials in constraint handler writing/parsing methods
6134 - SCIPcreateMesshdlrPThreads() and SCIPfreeMesshdlrPThreads() for allocating and deleting necessary memory
6135 for message handlers for parallel pthread version
6136 - SCIPallocClearMemoryArray() and BMSallocClearMemoryArray() for allocating cleared memory arrays in scip.h and memory.h
6139 - SCIPintervalPowerScalarInverse() to solve an equation y = x^p for given bounds on y and scalar exponent p
6140 - SCIPintervalQuadBivar() to compute tight bounds on a bivariate quadratic form
6141 - SCIPintervalSolveBivariateQuadExpressionAllScalar() to compute tight bounds on the solutions of a bivariate quadratic equation
6144 - SCIPcomputeVarCurrent{L,U}b{Local,Global}() to compute local or global lower or upper bounds of a
6145 multiaggregated variable from the bounds of the aggregation variables
6146 - SCIPbranchVarValNary() for n-ary variable branching
6147 - SCIPgetNegatedVars() which returns all negated variables for a given array of variables, if the negated
6148 variables are not existing yet, they will be created
6149 - SCIPgetNTotalVars() that returns the total number of created vars, icluding variables that were deleted in the meantime
6150 - SCIPvarGetHashkey(), SCIPvarIsHashkeyEq(), SCIPvarGetHashkeyVal() in pub_var.h which can be used for `SCIP_HASHTABLE` of variables
6151 - SCIPvarGetNBdchgInfosLb() and SCIPvarGetNBdchgInfosUb() in pub_var.h returning the number of lower or upper bound changes on the active path
6152 - SCIPvarGetBdchgInfoLb() and SCIPvarGetBdchgInfoUb() returning the bound change information at the given position
6153 - SCIPvarMarkDeletable() to mark a variable to be deletable completely from the problem (for
6154 branch-and-price); can only be called before the variable is added to the problem
6155 - SCIPvarMarkNotDeletable() that marks a variable to be non-deleteable (used within SCIP for forbidding
6156 deletion of variables contained in solution, LP bases, (multi)aggregation, ...)
6157 - SCIPvarIsDeletable() that returns whether a variable is marked to be deletable (each variable is per default non-deletable)
6160 - SCIPgetNLPVarsNonlinearity() to get for each variable in the NLP the number of NLP rows in which this variable appears in a nonlinear way
6161 - SCIPnlrowGetDualsol(), SCIPgetNLPVarsLbDualsol(), SCIPgetNLPVarsUbDualsol() to retrieve dual values from an NLP solution
6162 - SCIPgetNLPFracVars() to get the fractional variables in an NLP solution
6165 - SCIPpropSetPresolPriority() which changes the presolving priority of a given propagator
6166 - SCIPpropGetPresolPriority(), SCIPpropGetPresolTime(), SCIPpropWasPresolDelayed(), SCIPpropGetNFixedVars(),
6167 SCIPpropGetNAggrVars(), SCIPpropGetNChgVarTypes(), SCIPpropGetNChgBds(), SCIPpropGetNAddHoles(), SCIPpropGetNDelConss(),
6168 SCIPpropGetNAddConss(), SCIPpropGetNUpgdConss(), SCIPpropGetNChgCoefs(), SCIPpropGetNChgSides(), SCIPpropGetTimingmask(),
6169 SCIPpropDoesPresolve() which return corresponding presolving information
6170 - SCIPpropGetNRespropCalls() and SCIPconshdlrGetNRespropCalls() which return the number of times a
6171 propagator or a constraint handler was called for resolving a propagation
6172 - SCIPpropGetRespropTime() and SCIPconshdlrGetRespropTime() which return time spent for resolving a
6173 propagation within a propagator or a constraint handler
6174 - SCIPcheckCumulativeCondition(), SCIPpropCumulativeCondition() and SCIPrespropCumulativeCondition() in
6175 cons_cumulative.h; these methods can be used to check, propagate, or resolve the propagation of a cumulative condition
6176 - SCIPpropagateCutoffboundVar() in prop_pseudoobj.h which can be used to propagate the cutoff bound for the given variables
6179 - added to linear constraint handler SCIPsetUpgradeConsLinear(), which (de-)activates the possibility to
6180 upgrade a linear constraint to a specialized linear constraint (e.g. knapsack)
6181 - SCIPconvertCutsToConss() and SCIPcopyCuts() to scip.{c,h} for copying cuts to linear constraints
6182 - SCIPaddCoefLogicor() to add a variable to a logic or constraint
6183 - SCIPfindOrigCons() which return a original constraint with the given name or `NULL`
6184 - SCIPconshdlrGetNAddConss() which returns the number of added constraints during presolving by a given constraint handler
6185 - SCIPpresolGetNAddConss() which returns the number of added constraints during presolving by a given presolver
6187### Command line interface
6189- New funtionalities in the interactive shell (modify current CIP instance, write NLP relaxation)
6190- added dialog `write nlp` to write current NLP relaxation to a file
6191- new dialog `change freetransproblem` to free transformed problem in the interactive shell before changing the problem
6192- it is possible to change bounds of a variable in the interactive shell
6193- it is possible to add a constraint to a problem in the interactive shell
6195### Interfaces to external software
6197- Improved SOPLEX interface (LP simplifier)
6198- Improved CPLEX interface, including measures for numerical stability
6200### Changed parameters
6202- change default value of parameter `nodeselection/restartdfs/selectbestfreq` 100
6203- moved parameters for pseudoboolean constraints from opb-reader to pseudoboolean constraint handler
6204- changed possible parameter values of `branching/pscost/strategy` from `bri` to `cdsu`: default is now `u`, i.e., to
6205 estimate the LP gain by a branching for external branching candidates (esp. continuous variables) the same way as
6206 their pseudo costs are updated
6207- added possible value `d` for `constraints/soc/nlpform` to choose a convex division form for SOC constraint
6208 representation in NLP
6209- renamed parameter `constraints/quadratic/linearizenlpsol` to `constraints/quadratic/linearizeheursol` and do
6210 linearizations in every solution found by some heuristic
6211- renamed parameter `constraints/quadratic/mincutefficacyenfo` to `constraints/quadratic/mincutefficacyenfofac` and
6212 interpret it as a factor of the feasibility tolerance
6213- removed fastmip setting 2, which means the dualsolution would not be calculated but because SCIP always asks for the
6214 dual solution, the lp would be reoptimized to calculate them; so it had no real effect
6215- all parameters in cons_indicator and cons_sos1 have been converted to lower case!
6216- changed default value of parameter `separating/gomory/maxroundsroot` to 10
6217- changed default value of parameter `separating/gomory/maxsepacutsroot` to 50
6218- removed parameter `heuristics/subnlp/nlpsolver`, use `nlp/solver` instead
6222- `branching/delaypscostupdate` to delay the update of pseudo costs for continuous variables behind the separation round: default is TRUE
6223- `branching/lpgainnormalize` to set the strategy how the LP gain for a continuous variable is normalized when updating the
6224 variables pseudocosts: default is to divide LP gain by reduction of variable's domain in sibling node
6225- `branching/pscost/nchildren` and `branching/pscost/nary*` to enable and customize n-ary branching on
6226 external branching candidates (e.g., in spatial branching for MINLP)
6227- `conflict/bounddisjunction/continuousfrac` which defines the maximum percantage of continuous variables
6228 within a conflict create by the bounddisjunction conflict handler
6229- `conflict/separate` which enables or disables the separation of conflict constraints
6230- `constraints/{nonlinear,quadratic,soc,abspower}/sepanlpmincont` to specify minimal required fraction
6231 of continuous variables in problem to enable linearization of convex constraints in NLP relaxation solution in root
6232- `constraints/indicator/forcerestart` and `constraints/indicator/restartfrac` to control forced restart in cons_indicator
6233- `constraints/indicator/generatebilinear` to generate bilinear (quadratic) constraints instead of indicator constraints
6234- `constraints/indicator/maxconditionaltlp` to enable a quality check for the solution of the alternative LP
6235- `constraints/indicator/removeindicators` to remove indicator constraints if corresponding vub has been added
6236- `constraints/linear/nmincomparisons` and `constraints/linear/mingainpernmincomparisons` to influence
6237 stopping criterium for pairwise comparison of linear constraints
6238- `constraints/pseudoboolean/decompose`, for pseudoboolean constraints to transform pseudoboolean constraints into linear- and and-constraints
6239- `constraints/quadratic/binreforminitial` to indicate whether linear (non-varbound) constraints added due to reformulation of products with
6240 binary variables in a quadratic constraints should be initial (if the quadratic constraint is initial), default is FALSE
6241- `constraints/quadratic/checkfactorable` to disable check for factorable quadratic functions (xAx = (ax+b)*(cx+d)) in quadratic constraints
6242 and not to use of this information in separation (generates lifted tangent inequalities according to Belotti/Miller/Namazifar if also
6243 linear vars are present)
6244- `constraints/quadratic/disaggregate` to split a block-separable quadratic constraint into several quadratic constraint
6245- `constraints/quadratic/maxproprounds` and `constraints/quadratic/maxproproundspresolve` to limit the
6246 number of propagations rounds for quadratic constraints within one propagation round of SCIP solve or during SCIP presolve
6247- `constraints/varbound/presolpairwise` that allows pairwise presolving of varbound constraints, default is TRUE
6248- `heuristics/shiftandpropagate/onlywithoutsol` to switch whether the heuristic should be called in case a primal solution is already present
6249- `limit/maxorigsol` which defines the size of the solution candidate store (default value is 10)
6250- `lp/resolverestore` controlling how LP solution is restored after diving: if TRUE by resolving them,
6251 if FALSE by buffering them; if `lp/freesolvalbuffers` is TRUE, we free the buffer memory each time (FALSE by default)
6252- `lp/clearinitialprobinglp` to clear LP state at end of probing mode, if LP was initially unsolved
6253- `lp/resolveitermin` and `lp/resolveiterfac` to limit the number of LP iterations in resolving calls:
6254 resolveiterfac is a factor by which the average number of iterations per call is multiplied to get the limit, but the
6255 limit is at least resolveitermin; default is -1 (no limit) for resolveiterfac and 1000 for resolveitermin
6256- `lp/resolverestore` and `lp/freesolvalbuffers` possibility to buffer and restore LP solution after diving without
6257 having to resolve the LP; currently turned off, because performance impact is unclear;
6258- `misc/improvingsols` which states whether only solutions which have a better (or equal) primal bound
6259 as the best known are checked; this is of interest if the check of a solution is expensive; default value is FALSE
6260- `misc/resetstat` which state if the statistics should be reseted if the transformed problem is freed
6261 (in case of a benders decomposition this parameter should be set to FALSE) default value is TRUE
6262- `nodeselection/restartdfs/countonlyleafs` in node selector restart dfs which can be used to select the counting process of processed nodes
6263- `presolving/donotaggr` to deactivate aggregation of variables globally
6264- `pricing/delvars` and `pricing/delvarsroot` that define, whether variables created at a node / the
6265 root node should be deleted when the node is solved in case they are not present in the LP anymore
6266- `propagating/%s/maxprerounds` for all propagators which allows to change to maximal number of rounds
6267 of presolving where this propagator participates in
6268- `propagating/%s/presoldelay` for all propagators which allows to change if the presolving call of the given propagator should be delayed
6269- `propagating/%s/presolpriority` for all propagators which allows to change the priority of calling the given propagator
6270- `propagating/pseudoobj/propfullinroot` for allowing to propagate all variables in the root node,
6271 instead of stopping after `maxcands` which is set by a parameter as well
6272- `reading/gmsreader/bigmdefault` and `reading/gmsreader/indicatorreform` reader_gms is now able to write indicator
6273 constraints (reformulated either via big-M or sos1)
6274- `reading/gmsreader/signpower` to enable writing sign(x)abs(x)^n as the rarely used gams function signpower(x,n)
6275- `separating/closecuts/maxunsucessful` to turn off separation if we can not find cuts
6276- `timing/reading` to add reading time to solving time
6280- split off `PARAMEMPHASIS` from `PARAMSETTING` (in pub_paramset.c/paramset.c)
6281- new data structure `SCIP_STAIRMAP`
6282- add expression graph data structures and methods for reformulation, domain propagation, simple convexity check on
6283 nonlinear expressions and simplification for expression trees and graphs
6288- New scripts for running tests with GAMS
6289- added scripts check_gams.sh, evalcheck_gams.sh and check_gams.awk and target `testgams` in Makefile
6290- adjusted all test scripts to use the same new optimality gap computation as in SCIP
6291- added Makefile option `VALGRIND=true` to enable running the SCIP checks (make test) through valgrind; valgrind errors
6292 and memory leaks are reported as fails
6293- moved *.test and *.solu files to subdirectory testset in check directory and adjusted test scripts
6301 - via `PARASCIP=true` as a `Makefile` option it is possible to compile SCIP threadsafe in DEBUG-mode, (in OPT-mode it's
6302 only necessary if non-default messagehandler or CppAD is used)
6303 - the `make` parameter `PARASCIP=true` leads to threadsafe message handlers where you need to call
6304 SCIPcreateMesshdlrPThreads() and SCIPmessageSetHandler()/SCIPmessageSetDefaultHandler() and SCIPfreeMesshdlrPThreads();
6305 therefore we need to link with pthread library
6306 - new variable $(INSTALLDIR) in Makefile which define installation directory for the libraries, $(INSTALLDIR)/lib/,
6307 binary, $(INSTALLDIR)/bin and include headers, $(INSTALLDIR)/include, the default value is the empty string
6310 - Linking against Clp and Ipopt has been simplified. Only the directory where the
6311 package has been installed need to be provided now. For details see the INSTALL file.
6312 - to link against IPOPT, only the base directory of an Ipopt installation need to be specified now; additionally, if
6313 building with gnu compilers, the Ipopt libraries directory is stored in the SCIP binary, which should make it easier
6314 to run with Ipopt shared libraries
6315 - to link against Clp, only the base directory of an Clp installation needs to be specified now
6318 - New targets `(un)install` in Makefile, support for valgrind in testing environment
6319 - new target `make libs` which compiles only the libraries
6320 - new target in Makefile `install` performs `make` and copies using the install command the include headers, binary, and
6322 - new target in Makefile `uninstall` removes libraries, binary and include headers form `INSTALLDIR`
6323 - removed target `lintfiles`, this target is now imitated by the `lint` target and a none empty variable `FILES`
6328- fixed bug in copying if the target SCIP already is in solving stage: it might be that the copy of a variable cannot be found/created
6329- fixed bug trying to print big messages bigger than `SCIP_MAXSTRLEN`
6330- fixed bug w.r.t. counting feasible solutions and turned of sparse solution test
6331- LP solution status is now checked when checking root LP solution. Otherwise, due to different time measurements, it
6332 might happen that the LP solving was stopped due to the time limit, but SCIP did not reach the limit, yet.
6333- fixed bug trying to tighten multiaggregated variables, which have only one active representation and this variable is already tightened
6334- fixed possible buffer overrun in tclique_graph.c
6335- fixed issue with interactive shell in case (user) plugins are included after the default plugins
6336- fixed bug where mutiaggregating leads to an aggregation and both variables were of implicit or integral type
6337- fixed bug in conflict.c, where LPi was manipulated, but not marked as not solved
6340 - fixed assertion in tree.c w.r.t. node estimation
6341 - fixed bug in debug.c: removed tree nodes had not been checked if they were pruned due to an incumbent solution found by a diving heuristic
6344 - fixed bug which occured when changing a bound in the solving stage when this variables got upgraded from continuous to
6345 a integer type, where the bounds of this variable were still not integral; due to that SCIPchgVarType() has changed (see above)
6346 - fixed bug in handling of lazy bounds that resulted in putting the bounds explicitly into the LP
6349 - fixed assert in sepa_clique.c which is currently not valid because implicit binary variables in cliques are ignored
6350 - fixed bug in sepa_zerohalf.c concerning inconsistent construction of solution array of variables and fixed wrong assert about variable bounds
6353 - fixed not correct merging of variable in logicor constraint handler and changed the name of the method to a common
6354 name used by other constraint handlers too(findPairsAndSets->mergeMultiples)
6355 - fixed bugs in changing the initial and checked flags for constraints in original problem
6356 - fixed bug in cons_linear.c, when scaling a constraint maxabscoef was not set correctly, furthermore the correction of
6357 maxabscoef was not handled correctly
6358 - fixed bug in cons_indicator.c trying to copy a constraint where the pointer to the linear constraint did not point to
6359 the already transformed linear constraint (, happend when SCIPcopy() is used after transforming before presolving)
6360 - fixed numerical bug in linear constraint handler: polishing of coefficients after fixing variables led to wrong
6361 results for continuous variables fixed to a close-to-zero value.
6362 - fixed bug in cons_bounddisjunction where branching on multiaggregated variables was tried while all aggregation variables are fixed
6363 - fixed bug in presolving of cons_logicor.c: adding variable implications can lead to further reductions; added call to applyFixings()
6364 - fixed bug in cons_countsols.c w.r.t. none active variables
6365 - fixed bug in cons_linear.c, scaling could have led to wrong values
6368 - fixed bug in reader_fzn.c w.r.t. cumulative constraints
6369 - fixed bug in reader_mps.c: if a variables first occurence is in the bounds section, then the corresponding variable bound was lost
6370 - fixed several issues in flatzinc reader
6371 - deactived checking of zero solution in Zimpl reader when no starting values are provided
6372 - reader_lp is now able to read lines longer than 65534 characters
6375 - fixed bug in copying NLPI interfaces that use block-memory (NLPI copy used block memory from source SCIP)
6376 - fixed memory leak in reader_pip.c
6377 - fixed memory leak in coloring part of maximum clique algorithm (tclique_coloring.c)
6378 - fixed memory leak in coloring part of maximum clique algorithm (tclique_coloring.c) in a better way
6381 - fixed bug which occured when the dual farkas multipliers were not available in the lpi because the LP could only be
6382 solved with the primal simplex due to numerical problems
6383 - fixed bug in ZI round heuristic that led to infeasible shiftings for numerically slightly infeasible rows with close-to-zero coefficients
6384 - fixed numerical issue in octane heuristic: close-to-zero values for ray direction could have led to bad computations
6387 - fixed bug in propagation of indicator constraints: cannot fix slack variable to 0 if linear constraint is disabled/not active
6388 - fixed bug in cons_linear.c while sorting the eventdatas during the binary variable sorting for propagation
6389 - fixed bug and wrong assert in heur_shiftandpropagate.c when relaxing continuous variables from the problem
6390 - fixed bug in cons_orbitope:resprop() for the packing case
6391 - fixed wrong changing of wasdelayed flag for propagators
6392 - fixed bug using wrong sign in infinity check in prop_pseudoobj
6393 - fixed bug in redcost propagator: can only be called if the current node has an LP
6394 - fixed bug w.r.t. infinity loop during propagation
6399- The interface contains several additional callback functions and parameters for plugins. Some effort may be required to compile your old
6400 projects with SCIP 2.1. For details see section `Changes between version 2.0 and 2.1` in the doxygen documentation.
6402@page RN2_0 Release notes for SCIP 2.0
6404@section RN202 SCIP 2.0.2
6405*************************
6407Performance improvements
6408------------------------
6410- improved twoopt-heuristic by considering larger search domains
6411- the SoPlex interface now has the capability to provide a primal ray, provided it is compiled against the next SoPlex release (>= 1.5.0.2)
6412- calculation of node priority now also works when variable's relaxation value is equal to a bound
6413- fixed issue w.r.t. calling primal heuristics after presolving detected infeasibility
6416 - fasten propagation in cons_knapsack.c due to negated clique partitions
6417 - recalculating only needed partitions in cons_knapsack.c, not always both
6420 - reduced memory usage of shift-and-propagate heuristic
6421 - knapsack constraints are now separated faster; SCIPsolveKnapsackExactly() now works faster and requires less memory
6422 - fasten knapsack separation by replacing SCIPallocBuffer(Array) through SCIPallocBlockMemory(Array)
6423 - improved runtime and memory consumption in SCIPsolveKnapsackExactly() in cons_knapsack.c
6428- fixed `make/make.project`
6429- fixed wrong assert in plugins that use SCIPcopy()
6430- fixed bug in DINS w.r.t. column generation
6431- fixed bug in var.c where a possible multiaggregation was resolved to an aggregation but the variables types were not
6432 checked to prefer more general types for aggregating; possible memory loss removed
6433- fixed bug in prop_vbounds.c w.r.t. infinity lower and upper bound of variable bound variables
6434- fixed bug w.r.t. setting wall clocks
6435- fixed wrong assert in var.c (replaced `==` through SCIPsetIsEQ()), real values do not have to be exactly the same when
6436 computed in different function
6437- fixed bug in SCIPsolveIsStopped() where it could happen that TRUE was reported if a nodelimit was reached but
6438 checknodelimits had been set to FALSE
6439- fixed three bugs when writing in fzn format (wrongly splitted writing buffer, wrong variables was used, floats were printed to short)
6440- fixed bug in conflict.c, infeasibility analysis with big values led to wrong result
6443 - fixed bug in DINS heuristic that occured when the incumbent solution value is outside the variable's current domain
6444 - fixed behavior of LNS heuristics when the subproblem aborts: continue in optimized mode, stop in debug mode
6445 - fixed segmentation fault in heur_subnlp.c which occured if resolving the NLP with a tighter feasibility tolerance
6446 failed with a solver error
6447 - fixed bug in heur_subnlp.c where constraints forbidding variable fixations where added if a cutoff was used in the subproblem
6448 - fixed bug in heur_subnlp.c where wrong constraints forbidding variable fixations where added in case of general integers
6451 - fixed bug in changing quadratic coefficients of a row in the NLP
6452 - fixed various small bugs in nonlinear expressions code
6453 - fixed removal of fixed linear variables from a nonlinear row: a fixed variable may have not been removed if there was
6454 also a multiaggregated variable
6457 - implemented SCIPlpiGetPrimalRay() in SoPlex interface that has become available with SoPlex version 1.5.0.2
6458 - fixed two bugs at nodes with unbounded LP relaxation: don't check lp rows of infinite solution; don't analyze conflict
6459 due to primal cutoff bound of -infinity
6460 - fixed wrong assumption that an optimal LP solution in the root is optimal for the problem if there are no active
6461 pricers, need to check also whether all variables are in the LP
6464 - fixed bug in reader_cip regarding reading of very long constraints
6465 - fixed bug while after restarting possible the aggregted variables were not removed in setppc constraints
6466 - fixed bug in cons_knapsack: in seldom circumstances the relaxation of a linear constraint can detect infeasibility,
6467 which was not handled properly
6468 - fixed bug w.r.t. to pricing variables in case new initial constraints come in during the price and cut loop
6469 - fixed bug in cons_soc.c w.r.t. upgrading from quadratic constraints with finite left-hand-side
6470 - fixed bug caused by not (correctly) counting boundchanges in cons_varbound.c
6471 - fixed bug in sorting mechanism in cons_xor.c
6472 - fixed wrong (neg)cliquepartition check in cons_knapsack.c when deleting a coefficient
6473 - fixed bug in cons_quadratic: in seldom cases, fixed variables may have been substituted out wrongly in presolve
6474 - fixed bugs in cons_countsols.c w.r.t. collecting feasible solutions and forbidding a found solution
6475 - fixed bug in cons_linear.c: multiaggregated variables were not removed when adding during solve, leading to a failing
6476 assert in tightenBounds due to an unsuccessful bound tightening
6479 - fixed bug concerning overflow in memsize calculation in set.c
6480 - fixed memory leak in SoPlex LP interface when requesting an unbounded solution
6481 - fixed memory leak in SoPlex LP interface when solving with LP scaling
6482 - fixed memory leaks in reader of TSP example
6484@section RN201 SCIP 2.0.1
6485*************************
6487Performance improvements
6488------------------------
6490- SCIP with SoPlex as LP solver now uses auto pricing by default (start with devex, switch to steepest
6491 edge after some iterations); this fixes timeouts on instances where devex converges very slowly
6492- fixing lifting of new knapsack items which are negated items of already included items, this could lead to very long presolving
6493- fixed performance issue in presolving w.r.t. to computing the number of new fixings, aggregated,
6494 and so on before a constraint handler presolver is called
6495- in case of adding constraints during pricing with initial flag set to
6496 TRUE, we add now these constraints after the pricing round to the LP
6497- changed parameter values in clique separator in order to avoid very large branch-and-bound trees
6502### New and changed callbacks
6504- allow access of transformed constraints in `SCIP_STAGE_TRANSFORMED`
6506### Changed parameters
6508- replaced parameter `constraints/quadratic/minefficacy` by `constraints/quadratic/minefficacysepa` and `constraints/quadratic/minefficacyenfo`
6509- added possible values `a` and `e` for `constraints/soc/nlpform` to enable automatic choice and convex exponential-sqrt
6510 form for SOC constraint representation in NLP
6515- fixed bug w.r.t. looseobjval; the counting of number of loose variables in the LP data structure was incorrect in case
6516 a variable got aggregated or multi-aggregated
6517- fixed bug in copy method of objvardata which should only create a new `SCIP_VARDATA` if the implemented subclass create
6518 a copy of the given objvardata object
6519- fixed bug in lp.c where in case of objlimit reached and fastmip not all variables where priced because of an incorrect
6521- fixed bugs in binpacking example w.r.t. empty struct and not initializing an array
6522- fixed bugs in sepa_clique.c concerning incorrect way to ignore implicit binary variables in cliques and non-active
6523 variables in implications
6524- fixed some bugs w.r.t. to casting pointer arrays
6525- fixed bug in vars.c which handled arrays with parts of original variables during resolving to active variables (using
6526 SCIPvarsGetProbvarBinary) wrong
6527- fixed bug in nlp.c: nlrowSearchQuadElem was using SCIPquadelemSortedFind() incorrectly
6530 - fixed assertion w.r.t. to probing during the propagation round of a branch-and-bound node
6531 - fixed computation of node's objective value estimate when branching on continuous variables (see
6532 SCIPtreeCalcChildEstimate(), SCIPtreeBranchVar())
6533 - fixed bug in statistic w.r.t. number of calls for external branching candidates
6534 - fixes to branching on continuous variables
6537 - fixed bug in reader_gms.c: linear coefficients for quadratic variables were not printed if they had no
6539 - fixed bug in reader_mps: indicator constraints do not output the slack variables anymore
6542 - fixed bugs in SCIPcopyConss: copy all active constraints (including disabled ones), *valid was not initialized to TRUE
6543 - fixed bug in debug.c w.r.t. checking of constraints and continuous variables
6544 - fixed bug in cons.c which didn't allow the changing of the separation and enforcement flag of a constraint in the
6546 - corrected behavior of the copy function in cons_indicator.c: create artificial linear constraint if linear constraint
6548 - fixed bug in cons_indicator.c: presolving cannot delete linear constraints; several other minor bugfixes
6549 - fixed bugs in cons_bounddisjunction where the branching during the constraint enforcement was done incorrectly
6550 - fixed bugs in cons_orbitope.c: orbitopal fixing for the packing case had two bugs; also fixed one wrong assert
6551 - fixed bugs in cons_sos?.c: take average of objestimate
6552 - fixed bug in cons_logicor, implications on none `SCIP_VARTYPE_BINARY` variable were handled wrong
6553 - fixed bug in cons_linear while trying to add a conflict without any variables
6554 - fixed bug in cons_indicator.c: creating constraints in transformed stage is now possible
6557 - fixed bug w.r.t. memory allocation for all values of a column in lpi_cpx.c
6558 - fixed bugs in SCIPnlpiOracleChgLinearCoefs() and SCIPnlpiOracleChgQuadCoefs() for the case where new coefficients where
6560 - fixed bugs in lpi_none.c w.r.t. debug and opt mode
6561 - fixed bug in lpi_cpx.c w.r.t. to wrong handling in case the crossover did not succeed
6564 - fixed bug in heur_subnlp when initialized starting values of a fixed variable in the NLP of the subscip
6565 - fixed bug in heur_undercover: removed option globalbounds, since we are not allowed to relax bounds at a probing node
6566 - fixed bug in heur_shiftandpropagate where some variables were initialized too late
6567 - fixed numerical issue in some heuristics: nearly-integral values that are between the feasibility and the integrality
6568 tolerance might not have been rounded correctly
6569 - fixed bug in heur_guideddiving: best solution is now copied to avoid deletion in case of many new solutions
6570 - fixed bug in DINS heuristic, information storage for binary variables could lead to bad memory access in column
6571 generation applications
6572 - fixed bug in heur_shiftandpropagate.c: Now, the heuristic checks rows for global infeasibility at the beginning. This
6573 check is only relevant if presolving is disabled.
6574 - fixed bug in heur_subnlp when forbidding a particular combination of integer variables in the main problem
6576@section RN200 SCIP 2.0.0
6577*************************
6582- added relaxation structure to SCIP, it represents global relaxation information independent from a specific relaxator;
6583 at the moment, it contains information about the relaxation solution stored in the variables: objective value and
6585- SCIP may now be manually restarted
6586- SCIPsolveKnapsackExactly() got a new 12. parameter `SCIP_Bool* success` which stores if an error occured during
6587 solving(normally a memory problem)
6588- SCIP can now handle problems with continuous variables w.r.t. to counting (the projection to the integral variables
6590- an XML-parser is available in the src/xml subdirectory
6591- We do not distinguish between block memory for the original and the transformed problem anymore. The same
6592 block memory is now used in both problem stages.
6593- added new sorting method SCIPsortLongPtr(), SCIPsortDownLongPtr() and all corresponding methods
6594- added new sorting method SCIPsortRealIntPtr(), SCIPsortDownRealIntPtr() and all corresponding methods
6597 - SCIP can now copy instances (e.g. for heuristics)
6598 - new undercover heuristic for MINLPs: fixes variables such as to obtain a linear or convex subproblem and solves this
6599 - primal heuristics may now already be called before presolving, using the new timing point
6600 `SCIP_HEURTIMING_BEFOREPRESOL`. Note that solutions that are added before/during presolving, will be retransformed to
6602 - primal heuristics may now be called during presolving, using the new timing point `SCIP_HEURTIMING_DURINGPRESOLLOOP`
6603 - added heuristic zirounding (heur_zirounding.{c,h})
6604 - added heuristic twoopt (heur_twoopt.{c,h})
6605 - added new NLP heuristic (heur_subnlp.{c,h}) which solves the sub-NLP that is obtained by fixing all discrete variables
6606 in the CIP and applying SCIP's presolving
6607 - feasibility pump heuristic now implements all functionality for feasibility pump 2.0
6610 - can now read XML-solution files as used by CPLEX
6611 - the MPS reader can now read MIQPs and MIQCPs where a quadratic objective function can be specified by a QMATRIX or
6612 QUADOBJ section and the quadratic part of a quadratic constraint by a QCMATRIX
6613 - the MPS reader can now write quadratic and SOC constraints
6614 - the GAMS reader can now write SOC constraints
6615 - added support for bool_gt, bool_lt, bool_ge, bool_le, bool_ne, bool_not, int_times, int_minus, int_plus, int_negate,
6616 float_times, float_minus, float_plus, float_negate constraints to flatzinc reader
6617 - the LP reader (.lp files) can now read MIQPs and MIQCPs and write quadratic and SOC constraints
6618 - the LP reader (.lp files) and MPS reader can now read semicontinuous variables, they are handled by creating bound
6619 disjunction constraints
6620 - added new reader for polynomial mixed-integer programs (reader_pip.{c,h}) as used in the POLIP
6622- Indicator constraints:
6623 - SCIP can now handle indicator constraints (reading (from LP, ZIMPL), writing, solving, ...) see \ref cons_indicator.h.
6624 - the indicator constraint can now decompose the problem, i.e., not add the linear constraint to the problem if all of
6625 its variables are continuous
6626 - can now read and write indicator constraints in the (extended) MPS format
6627 - cons_indicator tries to adapt solutions to get feasible during check
6628 - cons_indicator allows to store information on other linear constraints that might help to separate cuts
6630- Constraint handlers:
6631 - Solution counting extended to constraint integer programs, this also
6632 includes constraint integer programs which contain continuous variables
6633 - The solution behavior of SCIP can be diversified by randomly permuting constraints and variables or randomly
6634 determining a set of branching variables with a unique high priority
6635 - `negated cliques` (1<=i<=n : sum (x_i) >= n-1) were added and we are using them now inside the knapsack constraint
6636 handler, the cliquepartitioning which is returned by SCIPcalcCliquePartition() contains now integer != 0, negatives ones
6637 indicates a negated clique and positive ones indicates a normal clique
6638 - SCIP is now able to detect in DEBUG-mode whether a constraint or variables which will be added, was also created in
6639 the same scip instance, if not an error is thrown
6640 - cons_knapsack is now able to detect negated cliques due to negated cliques on knapsack constraints
6641 - SCIP is now able to write non-linear opb-files(linear instances with and-constraints)
6642 - New constraint handlers for linking constraints (only Beta), cumulative constraints, and for breaking orbitopal symmetries
6643 - `negated cliques` handling in knapsack constraint handler got changed due to the new method
6644 SCIPcalcNegatedCliquePartition() resulting in new consdata members `negcliquepartition`, `negcliquepartitioned` and
6645 `nnegcliques`; changed SCIPcalcCliquePartition() so all cliquepartitions (calculated by SCIPcalcCliquePartition() or
6646 SCIPcalcNegatedCliquePartition(), which uses the first one) contain again not negative integers
6647 - `and`, `knapsack`, `linear`, `logic`, `or`, `quadratic`, `setpp`, `varbound`, `xor` and `clique` constraint handlers
6648 can handle implicit binary variables
6649 - knapsack constraint handler is now able to pairwise presolving constraints
6650 - constraint handlers `logicor`, `and`, `or` can parse their output
6651 - constraint handler `or` can copy its constraints
6652 - added packing/partitioning orbitope constraint handler for symmetry handling (cons_orbitope.{c,h})
6653 - added constraint handler for second order cone constraints (cons_soc.(c|h))
6654 - added constraint handler cons_linking.{c,h} (see cons_linking.c for more details)
6655 - cons_quadratic can make solutions in CONSCHECK feasible for the quadratic constraints by moving values of linear
6656 variables and passing the modified solution to the trysol heuristic
6657 - constraint handler can now register their upgrade functions for quadratic constraints to cons_quadratic (similar to
6661 - New separators for oddcycle cuts and Chvatal-Gomory cuts using sub-MIPs
6662 - modified implementation of separation algorithms in cons_knapsack.c according to results of diploma thesis; including
6663 super-additive lifting (disabled)
6664 - uncommented decomposeProblem() in sepa_zerohalf.c (in default settings, not used anyway): was not adapted to the case
6665 that contiuous variables are allowed in a row
6666 - new separator rapid learning (sepa_rapidlearning.{c,h}) that produces conflicts, global bound changes, primal
6667 solutions and initializes inference values for branching
6668 - added Chvatal-Gomory cuts separated with a sub-MIP (sepa_cgmip.{c|h})
6669 - added reader for 'Weigted Boolean Optimization': problems (reader_wbo.{c,h}), this reader needs the reader_opb files
6670 - new separator oddcycle (sepa_oddcycle.{c,h}) separates oddcycle inequalities using the implication/conflict graph and
6671 dijkstra-algorithm based on binary heaps (dijkstra/dijkstra_bh.{c,h})
6674 - Branching on externally given candidates, the \ref BRANCH 'branching rules' have a second new callback method
6675 (see type_branch.h for more details): SCIP_DECL_BRANCHEXECEXT(x) can be used to branch on external branching candidates,
6676 which can be added by a user's `relaxation handler` or `constraint handler` plugin, calling SCIPaddExternBranchCand().
6677 - added branchcands for relaxator solution, that can be added by the relaxator and used by branching rules
6678 - added relaxsol to variables, s.t. a relaxator can store a solution on which branching or separation can be done
6679 - SCIP can now branch on relaxation solutions that are either installed to the relaxsol field of the variables or added
6680 to the list of relaxation candidates, e.g., by constraint handlers. Branching on relaxation solutions is performed if
6681 the enforcement resulted in an unresolved infeasibility and there are no LP branching candidates, but before pseudo
6682 solution branching. The branching rules leastinf, mostinf, random and pscost implement the callback for branching on
6683 relaxation candidates.
6684 - SCIP can branch on continuous variables. The branching value x' must not be one of the bounds. Two children (x <= x',
6685 x >= x') will be created.
6686 - the vbc visualization adds the branching type (lower or upper bound change) and the new bound to the node information
6687 - the vbc visualization adds the new bound of the branched variable to the node information
6690 - added statistic information about the first primal solution to SCIP statistic; in the statistic output a new line
6691 appears with this information
6692 - now the statistic displays the number of calls of the feasibility checking method of each constraint handler and the
6696 - New rounding and propagation heuristics
6697 - New propagator for variable bounds
6698 - primal heuristics may now be called directly after the node's propagation loop, using the new timing point
6699 `SCIP_HEURTIMING_AFTERPROPLOOP`
6700 - following methods SCIPinferVarUbProp(), SCIPinferVarLbProp(), SCIPinferVarLbCons(), SCIPinferVarUbCons() have a new 6th
6701 parameter `SCIP_Bool force` which allows bound tightening even if the difference to the newbound is below bound
6702 strengthening tolerance
6703 - added propagator for variable lower and upper bounds (prop_vbounds.{c,h}); adjusted cons_varbound.c, var.c, and,
6704 implics.c to work correctly with the new propagator
6707 + Improved constraint handler for quadratic constraints
6708 + New constraint handler for second order cone constraints
6709 + New MINLP heuristics (undercover, subnlp)
6710 + Preliminary support for non-linear relaxations (via expression trees)
6711 + Automatic branching on solutions from arbitrary relaxations and on continuous variables
6713Performance improvements
6714------------------------
6716- improved `settings/emphasis/cpsolver.set` to decrease time per node
6717- reworked access to pseudo solution and inference value of variables in order to reduce function calls
6718- changed default value of parameter `nodeselection/restartdfs/selectbestfreq` to 0; this means if the current node has
6719 no children the node with the best bound is selected (SCIPgetBestboundNode())
6720- added a dual reduction step in cons_knapsack.c
6721- fasten check for common cliques in SCIPcliquelistsHaveCommonClique
6722- SCIP with CPLEX as LP solver now uses quickstart steepest edge pricing as default instead of steepest edge pricing
6723- avoid unnecessary domain propagation and LP resolve at nodes with infeasible LP relaxation
6724- improved zerohalf cut separator: more than one delta is tested for MIR cuts, better handling of dense base
6725 inequalities, faster scaling of fractional coefficients in rows (now enabled), improved parameter settings (presolving)
6728 - in root node, first LP solution is checked for feasibility to avoid expensive setup
6729 - avoided restarting if LP solution is feasible
6730 - separators are not called any longer for an integral initial LP solution
6732Examples and applications
6733-------------------------
6735- New branch-and-price example which includes Ryan/Foster branching (binpacking example)
6736- New example illustrating the use of an event handler (`example/Eventhdlr`)
6741- Enhanced user interface for callable library: manual restarts, predefined settings and many other features
6742- Support of wbo format for weighted PBO problems, IBM's xml-solution format and pip format for polynomial mixed-integer programs
6743- Extended reader for Flatzinc models
6744- new API for 'expressions interpreter': code that evaluates expression trees, including first and second derivatives
6745- NLP solver interface (NLPI) now independent of SCIP like LPI
6746- SCIP can now maintain a central NLP relaxation of the problem (similar to LP)
6747- SCIP can now manage a list of external codes (e.g., LP or NLP solver, ZIMPL)
6748- lp.h/lp.c and the lpi's were changed according to the changes mentioned below.
6749- adding and deletion of rows to the separation storage and to the LP can now be catched by events
6750 (`SCIP_EVENTTYPE_ROWADDEDSEPA`, `SCIP_EVENTTYPE_ROWDELETEDSEPA`, `SCIP_EVENTTYPE_ROWADDEDLP`, `SCIP_EVENTTYPE_ROWDELETEDLP`)
6752### New and changed callbacks
6754- new callback SCIP_DECL_BRANCHEXECRELAX(), together with new parameter in SCIPincludeBranchrule() for branching on a
6757- Copying a SCIP instance:
6758 - Constraint handlers have two new callback methods. One for copying the constraint handler plugins
6759 SCIP_DECL_CONSHDLRCOPY() and the other for copying a constraint itself, SCIP_DECL_CONSCOPY().
6760 - All plugins, like \ref BRANCH `branching rules` and \ref HEUR `primal heuristics`, have a new callback method (see, e.g.,
6761 type_branch.h and type_heur.h for more details):
6762 - SCIP_DECL_BRANCHCOPY(x), SCIP_DECL_HEURCOPY(x) etc.
6763 - When copying a SCIP instance, these methods are called to copy the plugins.
6764 - The main problem has a new callback method (see type_prob.h for more details) SCIP_DECL_PROBCOPY(x) when copying a
6765 SCIP instance, this method is called to copy the problem's data.
6766 - Variables have a new callback method (see type_var.h for more details) SCIP_DECL_VARCOPY(x) when copying a SCIP
6767 instance, this method is called to copy the variables' data.
6770 - The callback SCIP_DECL_PROBEXITSOL(x) in the main problem has one new parameter (see type_prob.h for more details):
6771 - The parameter `restart` is `TRUE` if the callback method was triggered by a restart.
6773### Deleted and changed API methods
6775- All C++ objects and constructors have a SCIP pointer, now.
6776- added parameter scip to ObjCloneable::clone()
6777- changes in a row can now be catched via row events (SCIPcatchRowEvent(), SCIPdropRowEvent(),
6778 `SCIP_EVENTTYPE_ROWCOEFCHANGED`, `SCIP_EVENTTYPE_ROWCONSTCHANGED`, `SCIP_EVENTTYPE_ROWSIDECHANGED`)
6779- added new parameter `varcopy` to SCIPcreateVar() to add the function for copying variable data
6780- in case of using SCIPwriteTransProblem() the currently (locally) valid problem is written this now also includes the
6784 - The predefined setting files like `settings/cuts/off.set,aggressive.set,fast.set` have been replaced by
6785 interface methods like SCIPsetHeuristics(), SCIPsetPresolving(), SCIPsetSeparating(), and SCIPsetEmphasis() in
6786 \ref scip.h and by user dialogs in the interactive shell like
6787 `SCIP> set {heuristics|presolving|separating} emphasis {aggressive|fast|off}` or
6788 `SCIP> set emphasis {counter|cpsolver|easycip|feasibility|hardlp|optimality}`
6789 - All functions for setting user parameters of different types like SCIPparamSetBool(), SCIPparamSetChar(),
6790 SCIPparamSetInt(), SCIPparamSetLongint(), and SCIPparamSetString() in pub_paramset.h have a new parameter
6791 `quiet` it prevents any output during the assign to a new value.
6794 - NLPIs can now be used without generating a SCIP instance (i.e., do not require a SCIP pointer), code moved into src/nlpi
6795 - NLPIs can now be managed like other SCIP plugins, i.e., they can be included into the SCIP core and accessed by
6796 methods SCIPincludeNlpi(), SCIPfindNlpi(), SCIPgetNNlpis(), SCIPgetNlpis(), SCIPsetNlpiPriority()
6798- Intervalarithmetic:
6799 - method SCIPgetVarPseudocostCurrentRun() now returns the pseudocost value of one branching direction, scaled to a unit
6800 interval, old method now called SCIPgetVarPseudocostValCurrentRun()
6801 - renamed SCIPintervalScalarProductRealsIntervals()/SCIPintervalScalarProduct() by
6802 SCIPintervalScalprodScalars()/SCIPintervalScalprod() and redesigned them in intervalarith.c including new methods
6803 SCIPintervalScalprodScalarsInf/Sup()
6806 - The usage of strong branching changed. Now, SCIPstartStrongbranch() and SCIPendStrongbranch() must be
6807 called before and after strong branching, respectively.
6808 - The methods SCIPgetVarPseudocost() and SCIPgetVarPseudocostCurrentRun() in \ref scip.h now return the pseudocost value of
6809 one branching direction, scaled to a unit interval. The former versions of SCIPgetVarPseudocost() and
6810 SCIPgetVarPseudocostCurrentRun() are now called SCIPgetVarPseudocostVal() and SCIPgetVarPseudocostValCurrentRun(), respectively.
6811 - The methods SCIPgetVarConflictScore() and SCIPgetVarConflictScoreCurrentRun() in \ref scip.h are now called
6812 SCIPgetVarVSIDS() and SCIPgetVarVSIDSCurrentRun(), respectively.
6813 - The methods SCIPvarGetNInferences(), SCIPvarGetNInferencesCurrentRun(), SCIPvarGetNCutoffs(), and
6814 SCIPvarGetNCutoffsCurrentRun() are now called SCIPvarGetInferenceSum(), SCIPvarGetInferenceSumCurrentRun(),
6815 SCIPvarGetCutoffSum(), and SCIPvarGetCutoffSumCurrentRun(), respectively. Furthermore, they now return
6816 `SCIP_Real` instead of `SCIP_Longint` values.
6817 - The method SCIPgetVarStrongbranch() has been replaced by two methods SCIPgetVarStrongbranchFrac() and
6818 SCIPgetVarStrongbranchInt().
6820- Copying a SCIP instance:
6821 - Every new callback method resulted in a new parameter of the include function for the corresponding plugin,
6822 e.g., SCIPincludeBranchrule() has two new parameters `SCIP_DECL_BRANCHCOPY((*branchcopy))` and
6823 `SCIP_DECL_BRANCHEXECREL((*branchexecrel))`. In the same fashion, the new callbacks
6824 `SCIP_DECL_VARCOPY` and `SCIP_DECL_PROBCOPY` led to new parameters in SCIPcreateVar() and SCIPcreateProb() in
6825 scip.c, respectively.
6826 - W.r.t. to copy and the C++ wrapper classes there are two new classes. These are `ObjCloneable` and `ObjProbCloneable`.
6827 The constraint handlers and variables pricers are derived from `ObjProbCloneable` and all other plugin are derived from `ObjCloneable`.
6828 Both classes implement the function `iscloneable()` which return whether a plugin is clone able or not. Besides that each class has a
6829 function named `clone()` which differ in their signature. See objcloneable.h, objprobcloneable.h, and the TSP example for more details.
6830 - SCIPincludeHeur() and SCIPincludeSepa() in \ref scip.h, as well as scip::ObjSepa() and scip::ObjHeur(), have a new parameter:
6831 `usessubscip`: It can be used to inform SCIP that the heuristic/separator to be included uses a secondary SCIP instance.
6832 - The argument success in `SCIP_DECL_CONSCOPY` has been renamed to valid.
6835 - SCIPcutGenerationHeuristicCmir() in sepa_cmir.h has three new parameters:
6836 - `maxmksetcoefs`: If the mixed knapsack constraint obtained after aggregating LP rows contains more
6837 than `maxmksetcoefs` nonzero coefficients the generation of the c-MIR cut is aborted.
6838 - `delta`: It can be used to obtain the scaling factor which leads to the best c-MIR cut found within
6839 the cut generation heuristic. If a `NULL` pointer is passed, the corresponding c-MIR cut will already be
6840 added to SCIP by SCIPcutGenerationHeuristicCmir(). Otherwise, the user can generate the cut and add it to SCIP
6841 on demand afterwards.
6842 - `deltavalid`: In case, the user wants to know the best scaling factor, i.e., `delta` passed is not `NULL`,
6843 `deltavalid` will be `TRUE` if the stored scaling factor `delta` will lead to a violated c-MIR cut.
6845### New API functions
6847- added SCIPcalcNegatedCliquePartition() to scip.c to calculate a clique partition on negations of all given binary
6849- SCIPpermuteArray() that randomly shuffles an array using the Fisher-Yates algorithm
6850- SCIPgetRandomSubset() that draws a random subset of disjoint elements from a given set of disjoint elements
6852- SCIPlpiGetSolverDesc() to get a descriptive string of an LP solver (developer, webpage, ...)
6853- SCIPholelistGetNext() to get the next hole of the hole list
6854- SCIPlpRecalculateObjSqrNorm() which is used when the old calculated square norm was unreliable
6855- SCIPpricerIsDelayed() which returns if the pricer is delayed (see pub_pricer.h)
6858 - SCIPvarIsBinary() which checks if a variable is (implicit) binary (see var.c for more details)
6859 - SCIPvarGetHolelistOriginal(), SCIPvarGetHolelistGlobal(), SCIPvarGetHolelistLocal() to get the original, global and local holes, respectively
6860 - SCIPvarGetProbvarHole() to tranform a given domain hole to the corresponding active, fixed, or multi-aggregated variable
6863 - allow user to trigger a restart during presolving SCIPrestartSolve()
6864 - SCIPrestartSolve() that allows the user to manually restart the solving process
6865 - SCIPisInRestart() to detect whether we are currently restarting
6868 - for heuristics SCIPheurSetFreq() to change the frequency of the heuristic (pub_heur.h, heur.c)
6869 - SCIPsepaUsesSubscip(), SCIPheurUsesSubscip()
6871- Intervalarithmetic:
6872 - SCIPeventGetHoleLeft() and SCIPeventGetHoleRight() for accessing the left right interval bound of a domain hole added or removed event
6873 - SCIPholelistGetLeft() and SCIPholelistGetRight()to get the left and right interval bounds of the open hole interval
6874 - SCIPintervalAddInf/Sup/Vectors(), SCIPintervalMulInf/Sup() in intervalarith.c
6877 - added SCIPsortPtrPtrLongIntInt(), SCIPsortLongPtrPtrIntInt() and corresponding sorting/inserting/deleting methods in
6878 pub_misc.h and necessary defines in misc.c
6879 - added SCIPsortLongPtrInt() and corresponding sorting/inserting/deleting methods in pub_misc.h and necessary defines in misc.c
6880 - added SCIPsortPtrPtrInt() (and various other) and corresponding sorting/inserting/deleting methods in pub_misc.h and
6881 necessary defines in misc.c
6882 - SCIPsortPtrBool() and corresponding sorting/inserting/deleting methods in pub_misc.h and necessary defines in misc.c
6884- Constraint Handlers:
6885 - SCIPconshdlrGetEnfoConss(), SCIPconshdlrGetNEnfoConss()
6886 - can now forbid upgrading of individual linear constraints (SCIPmarkDoNotUpgradeConsLinear())
6887 - SCIPpermuteProb() that randomly permutes constraints and variables
6888 - SCIPgetResultantOr() which returns the resultant of an `or` constraint
6889 - SCIPmarkDoNotUpgradeConsLinear() in cons_linear.?, which allows to forbid upgrading of linear constraints
6890 - SCIPgetNUpgrConss() which returns the number of upgraded constraints
6891 - SCIPconshdlrGetCheckTime() and SCIPconshdlrGetNCheckCalls() which returns the running time in the feasibility checking of the
6892 corresponding constraint handler respectively the number of calls of the checking method (implemented in cons.c)
6895 - SCIPcopy() to clone a SCIP instance
6896 - SCIPcopyPlugins(), SCIPcopyParamSettings(), SCIPcopyVars(), SCIPcopyConss(), SCIPgetVarCopy() to copy
6897 individual parts of a SCIP instance separately.
6898 - SCIPcopyProbData() and SCIPprobCopyProbData() which copies the probdata from a sourcescip to a targetscip
6901 - two new functions SCIPgetVarsStrongbranchesFrac()/SCIPgetVarsStrongbranchesInt() for computing strong branching
6902 information for several variables
6903 - SCIPbranchruleGetNRelaxCalls() to get the total number of times, a particular branching rule was called on a relaxation solutions
6904 - SCIPbranchRelax() to branch on a relaxation solution
6905 - SCIPbranchVarVal() to branch on an arbitrary value within the variable's bounds
6906 - SCIPbranchGetBranchingPoint() and SCIPgetBranchingPoint() to select branching point for a variable, e.g.,
6907 ensure branching point is inside the interval for a continuous variable
6908 - SCIPexecRelpscostBranching() in branch_relpscost.{c,h}; this method allows of calling the reliability
6909 pseudo cost branching algorithm for given set of branching candidates from the outside
6910 - SCIPinitVarBranchStats() to initialize the branching statistics (such as pseudo costs, VSIDS, inference values) of a variable
6911 - SCIPselectBranchVarPscost() in branch_pscost.{c,h}; this method selects from a given candidate array a
6912 branching variable w.r.t. pseudo cost branching for relax candidates
6914- Reading, Writing and Parsing:
6915 - SCIPparseVarName() which parses a string in cip-format as a variable name
6916 - SCIPparseVarList() which parses a string as a variable list in cip-format
6917 - the Flatzinc reader can now handle the output annotations of the Flatzinc format; the method SCIPprintSolReaderFzn()
6918 outputs the given solution in Flatzinc format w.r.t. the output annotations
6919 - SCIPprintSolReaderFzn() which prints the best solution in Flatzinc format w.r.t. to the output annotations
6920 in the input file of the flatzinc model
6921 - SCIPwriteVarName() which writes a variable in cip-format to given stream
6922 - SCIPwriteVarsList() which writes an array of variables in cip-Format to given stream
6923 - SCIPwriteVarsLinearsum() which writes an array of variables and coefficients as linear sum in cip-Format to given stream
6925- Copying a SCIP instance:
6926 - SCIPapplyRens() in \ref heur_rens.h has a new parameter `uselprows`. It can be used to switch from LP rows
6927 to SCIP constraints as basis of the sub-SCIP constructed in the RENS heuristic.
6930 - SCIPsetParamsCountsols() which sets the parameter for a valid counting process
6931 - SCIPsetEmphasis() which sets parameter to detect feasibility fast, handle hard LP, solves easy CIPs fast, behaves like a
6932 CP solver, set parameter for a valid counting process; the desired behavior is triggered via a parameter of the function
6933 - SCIPresetParam() to reset the value of a single parameter to its default value
6936 - added SCIPsortRealRealRealPtr() and corresponding sorting/inserting/deleting methods in pub_misc.h and necessary defines in misc.c
6937 as basis for the subSCIP, setting ist to TRUE (uses LP rows) will lead to same version as before
6938 - SCIPsetHeuristics(), SCIPsetSeparating(), SCIPsetPresolving() which set the heuristics to aggressive, fast, off, or
6939 default settings, depending on the `SCIP_PARAMSET` parameter
6940 - SCIPsetSubscipsOff() which disables all plugins that uses subscips
6941 - SCIPsepaSetFreq() to set the calling frequency of a separator
6943### Command line interface
6945- added new dialog for setting the SCIP parameters for hardlp, optimality, easy CIP, CP like search
6946- added new dialog for setting the SCIP parameters for feasibility problems `SCIP> set emphasis feasibility`
6947- added new dialog for setting the SCIP parameters for counting `SCIP> set emphasis counting`
6948- added new dialog for setting presolving to aggressive, fast, or off in interactive shell
6949- added new dialog for setting separation to aggressive, fast, or off in interactive shell
6950- added new dialog for writing all solutions which are collected during the counting process (see cons_countsols.{c,h})
6951- added new dialog for setting heuristics to aggressive, fast, or off in interactive shell
6952- added new dialog `display pricers` which displays all included pricers
6954### Interfaces to external software
6956- added interface to CppAD (nlpi/exprinterpret_cppad.cpp)
6957- Improved Xpress, CPLEX, SoPlex interfaces
6958- the SoPlex interface now includes equilibrium scaling on lp's solved from scratch without starting basis
6959- the SoPlex interface can now double check each SoPlex result against CPLEX (lpi_spx.cpp)
6960- the SoPlex interface has the option to restore basis only after entire strong branching phase instead of after each
6961 strong branch (off, because it mostly appears to increase strong branching time and iterations) (lpi_spx.cpp)
6963### Changed parameters
6965- removed parameter `constraints/knapsack/maxnumcardlift` and adapted setting files
6966- changed parameter `lp/fastmip` from boolean to integer, possible values are 0 (off), 1 (medium, default), 2 (full,
6967 must not be used with branch-and-price).
6971- `branching/clamp` to set the minimal fractional distance of a branching point to a continuous variable' bounds
6972- `branching/random/seed` to change the initial seed value of the branching rule random
6973- `constraints/indicator/addCouplingCons` that allows to add variable upper bounds if addCoupling is true
6974- `constraints/indicator/enforceCuts` that allows to check for violated cust in enforcement
6975- `constraints/indicator/maxCouplingValue` for the maximal value of the coefficient in a coupling inequality/constraint
6976- `constraints/indicator/noLinconsCon` which controls whether the linear constraint is not explicitly
6977 added to the problem. default is FALSE
6978- `constraints/knapsack/dualpresolving` to switch dualpresolving on/off inside the knapsack constraint handler, default is TRUE
6979- `constraints/knapsack/presolpairwise` that allows pairwise presolving of knapsack constraints, default is TRUE
6980- `constraints/knapsack/presolusehashing` that allows fast pairwise presolving of knapsack constraints, default is TRUE
6981- `heuristics/crossover/dontwaitatroot` that allows to call crossover at root node independently from nwaitingnodes
6982- `heuristics/rens/uselprows` that allows to switch between LP row and SCIP constraints as basis for the
6983 subSCIP, default is TRUE (uses LP rows)
6984- `lp/rowrepswitch` telling simplex solver to switch to row representation of the basis (if possible),
6985 if number of rows divided by number of columns exceeds this value (default value infinity, i.e. never switch)
6986- `lp/threads` to change the number of threads used to solve the LP relaxation (default is 0: automatic)
6987- `misc/lexdualstalling` that turns on the lex dual algorithm if the separation process is stalling
6988- `misc/usevartable` and `misc/useconstable` which turns on/off the usage of hashtables mapping from
6989 variable/constraint names to the variables/constraints; when turned off, SCIPfindVar() and SCIPfindCons() may not be
6990 used; the hashtables can be turned off for subMIPs to improve the performance, default value TRUE
6991- `misc/usesmalltables` which results in using smaller tables for names, cliques and cuts and improves
6992 the performace for smaller instances, default value FALSE
6993- `misc/permutationseed` to change the permutation seed value for permuting the problem after the
6994 problem is transformed (-1 means no permutation)
6995- `reading/zplreader/usestartsol` which allows to switch ZIMPL start solutions off, default value TRUE
6996- `vbc/dispsols` to propose if the nodes where solutions are found should be visualized in the branch and bound tree
7000- implemented the data structure and events for global and local domain holes added and removed
7001- new data structures and methods to handle nonlinear expressions in NLPI ({type_, struct_, pub_}expression.{h,c}):
7002 nlpioracle can store and evaluate general NLPs now, nlpi_ipopt can solve general NLPs now
7007- minor changes on several evaluation scripts (new statuses: better, solved, sollimit, gaplimit) and short-mode for cmpres.awk
7008- support for FreeBSD (32- and 64-bit) including minor changes in several scripts in the check-directory
7015- added scripts check_*.sh, evalcheck_*.sh and check_*.awk for blis, glkp, gurobi and symphony (including targets in
7016 Makefile) and slightly modified scripts for cplex, cbc and mosek and cmpres-script
7017- added target `lintfiles` which allows to call flexelint with a list of file, for example, make lintfiles
7018 `FILES=src/scip/prop_vbounds.c`
7019- the NLP solver interfaces and expression interpreter are located in a separate library (libnlpi.*; similar to the lpi
7020 library) and is required to link against the SCIP library also projects that use SCIP via `make/make.project` need to
7021 change their Makefile (!!!): in the $(MAINFILE) target, add $(NLPILIBFILE) behind $(LPILIBFILE) in the dependencies
7022 and add $(LINKCXX_l)$(NLPILIB)$(LINKLIBSUFFIX) to the linker flags
7023- The additional NLPI library requires a change in the Makefile of SCIP's project:
7024 The $(MAINFILE) target now has $(NLPILIBFILE) as additional dependency and the linking
7025 command requires $(LINKCXX_l)$(NLPILIB)$(LINKLIBSUFFIX) as additional argument.
7026- A bug in the Makefiles of older versions of the SCIP examples may cause
7027 data loss. If you have a custom Makefile, please ensure that the target
7028 `clean` is changed as described here:
7029 http://scipopt.org/download/bugfixes/scip-1.2.0/make.txt.
7034- fixed bug in conflict.c in the method conflictsetAddBound()
7035- fixed `bug` in projects Makefiles w.r.t. `make clean`
7036- fixed bug in rapid learning with wrong ordering of dual and primal bound update, primal bound is now updated inside
7038- fixed potential bug in rapid learning with dual reductions
7039- fixed potential bug where SCIPselectSimpleValue() returns a value slightly outside of the given bounds due to rounding
7040 errors (probably cancelation in subtraction in SCIPfindSimpleRational), now use rounding control and check result
7041- fixed bug that SCIP could not be continued after it has been stopped due to a limit
7042- fixed bug in var.c: SCIPvarChgLbOriginal() and SCIPvarChgUbOriginal() cannot access original bounds if the variable is
7044- fixed potential bug with pseudo solution branching on free variables
7045- fixed bug with multiaggregations whose infimum and supremum are both infinite: in such a case multiaggregation is now
7047- fixed numerical issue with multiaggregations which are infinite in one direction: value of multiaggregated variable
7048 could have been larger then inifinity
7049- fixed bug w.r.t. of adding a variable bound variable to its self
7050- fixed bug concering the incorrect assumption that every solution computed in SCIPlpGetUnboundedSol() is integral (we
7051 will not branch but return `infeasible or unbounded` like in presolving)
7052- fixed bug while breaking an clique down to their impications (in SCIPcliquetableCleanup() in implics.c) where the
7053 variable was not of vartype `SCIP_VARTYPE_BINARY`, instead of adding an implication we add a variable bound
7054- fixed bug with debugging a solution: during restarts erroneously it was claimed that the primal solution is cut off
7057 - fixed bug w.r.t. ObjDialog and displaying the description of the dialog
7058 - fixed bug when aborting pricing with Ctrl-C
7061 - fixed bug in scip.c w.r.t. to call of conflict analysis for LPs which reached the objective limit in case of diving
7062 - fixed bug with resolving LPs at infeasible root node
7063 - fixed bug in lp.c: in sumMIRRow() rowtoolong was not set correctly
7064 - fixed bug in lp.c w.r.t. objective limit reached and the chosen comparison (fixed buglist entry 40)
7065 - fixed bug in lp.c: if in SCIPlpSolveAndEval() the LP has to be solved from scratch due to numerical troubles, reset
7066 `SCIP_LPPARAM_FROMSCRATCH` to `FALSE` afterwards
7067 - fixed bug in lp.c SCIProwGetObjParallelism() due to a wrong parallelism value which arised from cancellations during
7068 calculation of squared euclidean norm of objective function vector of column variables
7069 - fixed bug in lp.c: SCIPlpGetUnboundedSol() did not ensure that unbounded solution lies withing the bounds of the
7071 - fixed bug in lp.c w.r.t. to the number of `active` pricer
7074 - fixed bug in solve.c where relaxation branching candidates were cleared, but the relaxation was still marked solved
7075 and not called again, furthermore, adjusted criterions for solving a relaxation again
7076 - fixed bugs in solve.c: even with LP solving disabled, the root LP was solved in case continous variables are
7077 contained; setting pricing/maxvars(root) to 1 resulted in not calling the pricers
7078 - fixed bug in solve.c: make sure SCIP terminates correctly also when a user interrupt or gap limit is reached, i.e.,
7079 avoid error `pricing was aborted, but no branching could be created!`
7082 - fixed bug in tree.c: if an explicit branching point is given, we may not recompute a better centering point
7083 - fixed bug in tree.c: propagate implications on multi-aggregated should not be performed
7086 - corrected several asserts in linear and quadratic constraint handler concerning parsing of CIP format
7087 - fixed bug while deleting redundant variables, which have no influence on changing the feasibility of the linear
7088 constraints, we need to update the sides of the constraint at each step, bug number 51 in bugzilla
7089 - fixed bug in copy procedure of AND constraint handler, negated variables have been copied to their originals
7090 - fixed bug when deleting a constraint where the update was delayed and not processed yet (in cons.c)
7091 - fixed bug in cons_linear.c: binary variables should not be multi-aggregated
7092 - fixed bug in cons_quadratic.c: curvature of bivariate quadratic constraints was not detected correctly
7093 - fixed bug in cons_sos2.c: the branching position was sometimes mistakenly increased
7094 - fixed bug in propagation of cons_sos2.c: the node can be cut off at more places: the previous version was not
7095 sucessfull in this respect
7096 - fixed bug in cons_linear.c:applyFixings() which could lead to lhs/rhs smaller/larger than -/+infinity
7097 - fixed bug in cons_linear.c in detectRedundantConstraints() and corrected old bug fix in SCIProwCreate(): we want lhs
7098 <= rhs to be satisfied without numerical tolerances in order to avoid numerical problems in the LP solver
7100- Knapsack Constraint Handler:
7101 - fixed bug in cons_knapsack.c: mergeMultiples() now detects whether a node can be cut off
7102 - fixed bug in cons_knapsack.c w.r.t. to items with zero weight
7103 - fixed bug in cons_knapsack.c: In SCIPseparateRelaxedKnapsack() not all variables need to be active in deeper regions
7105 - fixed bug in cons_knapsack.c and sepa_clique.c: the assumption that implications are always nonredundant and contain
7106 only active variables is not correct anymore as the corresponing vbound might be missing because of numerics
7108- Separation and Cuts:
7109 - fixed bug in cutpool.c: the hashkey computation was not constant over time
7110 - fixed bug in cutpool.c: hashkey of a row changed during the solving process (if a row is made integral after creation,
7111 maxabsval can be invalid when adding it to the pool, but might be recomputed later on)
7112 - fixed bug in sepa_rapidlearning.c, stop processing if there are no binary variables left
7113 - fixed bug in sepa_rapidlearning.c, corrected computation of right dualbound
7114 - fixed bugs in sepa_zerohalf.c, e.g., handling of intscaling and substitution of variable bounds
7115 - fixed bug in sepastore.c in sepastoreApplyLb/Ub being to hard on feasibility decisions
7116 - fixed bug in sepa_flowcover.c: numerical issues while computing candidate set for lambda
7119 - fixed bug in SoPlex autopricing due to which autopricing had behaved like steepest edge pricing so far
7120 - fixed bug in lpi_clp.cpp: SCIPlpiChgBounds() checks if the column status exists in Clp before using it
7121 - fixed wrong assert in Cplex LPI: Due to numerical inaccuracies, a few pivots might be performed after refactorization
7122 - fixed bug concerning assert(!SCIPlpDivingObjChanged(lp)) which was caused by wrong infinity double parameters for
7124 - fixed makefile system for `OSTYPE=darwin` w.r.t. to CPLEX as LP solver
7127 - fixed bug in cons_setppc: aggregated variables were not correctly removed in presolving
7128 - fixed bug in presolving of linear constraint handler: in redundancy detection, two different numerical epsilons were used
7129 - fixed bug in presolving while not applying a bound change on a variable in a single-variable constraint (e.g. x1 =
7130 0.03) in cons_linear which is too small, that lead to another bound change in presol_trivial which is not allowed, so
7131 now this bound change will be forced
7132 - fixed SCIPvarIsTransformedOrigvar() in var.c (variables generated by presol_inttobinary returned false)
7133 - fixed bug w.r.t. an assert in presol_inttobinary.c; it was assumed that the aggregation which is performed there will
7134 never lead to an infeasibility, this is not true, see comment in presol_inttobinary.c
7135 - fixed bug in presol_trivial.c trying to fix continuous variables, now uses a less stricter comparison to fix variables
7136 - fixed bug in cons_bounddisjunction.c: presolve may have tried to tighten bounds on a multiaggregated variable (now
7137 upgrades to linear constraint)
7139- Reading, Writing and Messages:
7140 - fixed bug while trying to write a MIP where SCIP needs to flush the lp changes first
7141 - fixed potential resource leak when running out of memory while writing files
7142 - fixed bug in reader_zpl.c which appeared using the parameter `reading/zplreader/parameters`
7143 - fixed bugs in flatzinc readers with constraints that exclusively consist of constants
7144 - fixed bug in reader_gms: correct handling of nonstandard bounds on general integer variables
7145 - fixed buglist entry 35, which was caused by a wrong read in correction when the reading buffer was full in
7147 - fixed bugs in reader_fzn.c w.r.t. parsing and solution output in Flatzinc format
7148 - fixed bug in reader_fzn.c w.r.t. comment lines
7149 - fixed bug in reader_opb.c w.r.t. comment lines
7150 - fixed bug in message handler w.r.t. to messages which are longer then `SCIP_MAXSTRLEN`
7153 - fixed bugs do to `HEUR_TIMING SCIP_HEURTIMING_AFTERPROPLOOP` which appeared during repropagation
7154 - fixed bug in trivial heuristic: the locking solution might have falsely initialized some values to zero
7155 - fixed bug in heur_oneopt.c w.r.t. to SCIPtrySol(); it is necessary that the bound of the solution is check otherwise,
7156 infeasible solution could be accepted as feasible
7157 - fixed bug in heur_trivial.c w.r.t. to debug messages after a solution was freed
7158 - fixed bug for `HEUR_TIMING SCIP_HEURTIMING_BEFOREPRESOL` and modifiable constraints
7159 - corrected wrong assert in DINS heuristic when called for an empty problem
7160 - fixed potential bug in OCTANE heuristic with nonbasic solutions
7161 - fixed bug in sub-MIP heuristics with parameter change if some default plugins are not included
7162 - fixed bug in trivial heuristic with bounds that are greater than the heuristic's infinity value
7167- As the interface contains several additional callback functions and
7168 parameters for plugins, some effort may be required to compile your
7169 own projects with SCIP 2.0. See also `Changes between version 1.2 and 2.0` in the doxygen
7170 documentation for additional information.
7172@page RN1_2 Release notes for SCIP 1.2
7174@section RN120 SCIP 1.2.0
7175*************************
7180- adjusted hard memory limit to (soft memory limit)*1.1 + 100mb in check.sh, checkcount.sh, check_cplex.sh,
7181 check_cluster.sh and check_cbc.sh
7182- new presolving step in cons_knapsack.c, same like `simplifyinequalities` in cons_linear.c
7183- now it's possible to write strings with more than `SCIP_MAXSTRLEN` amount of characters in all message.c functions
7184- the current/root lp can be marked to be no relaxation of the current/root problem
7185- added new preprocessing step (mergeMultiples) in cons_setppc.c where equal variables are merged
7186- Black-box lexicographic dual simplex algorithm; can now run lexicographical dual algorithm (parameter `lp/lexdualalgo`)
7189 - SCIP now has `lazy bounds`, which are useful for column generation: see @ref PRICER_REMARKS `pricer remarks` for an explanation.
7190 Each variable has now two additional `SCIP_Real` parameter which define a lazy lower and upper bound; lazy means that
7191 there exists constraints which implies these (lazy) bounds. If the lazy lower or upper bound is greater or less than
7192 the local lower or upper bound, respectively, then the corresponding bound is not put into the LP. The bounds are set
7193 to minus and plus infinity per default which yields the same behavior as before. With the methods SCIPchgVarLbLazy()
7194 and SCIPchgVarUbLazy() these bounds can be set. This is of interest if SCIP gets used as a branch-and-price
7195 framework. Attention! The lazy bounds need to be valid for each feasible LP solution. If the objective function
7196 implies bounds on the variables for each optimal LP solution, but these bounds may be violated for arbitrary LP
7197 solutions, these bounds must not be declared lazy!
7198 - interval arithmetic functions can work with unbounded intervals added new functions to allow more operations on
7199 intervals, including solving quadratic interval equations
7202 - extended hybrid relpscost branching rule by usage of the average length of conflicts a variable appears in
7203 - `early branching`-functionality added: in a branch-and-price code, the user can stop pricing at a node although there
7204 may exist variables with negative reduced costs. In this case, the lp-lowerbound will not be used. The pricer has,
7205 however, the option to return a lower bound. This can be useful for column generation.
7208 - Copy constructors and i/o functionality for constraints: all linear type constraint handlers are able to copy
7209 constraints using the function SCIPgetConsCopy() in scip.h
7210 - the linear constraint handler is able to parse a string in CIP format and create a corresponding linear constraint
7211 - Constraint handler for indicator constraints and parsing them from *.lp and *.zpl files
7212 - the indicator constraint can now try to produce a feasible solution (via heur_trysol)
7213 - one can now write indicator constraints in LP-format
7214 - added constraint handler for quadratic constraints
7217 - added new version of zerohalf cuts from Manuel Kutschka
7218 - added multi-commodity-flow cut separator
7221 - Heuristics which are applied before root LP
7222 - added heuristic that performs a local search in an NLP (takes only linear and quadratic constraints into account so far)
7223 - added heuristic that gets a solution from other components and tries it (heur_trysol.?)
7224 - new trivial heuristic: tries zero solution, lower and upper bound solution and some variable lock based fixing
7225 - added new timing point, `SCIP_HEURTIMING_DURINGPRICINGLOOP`, for calling heuristics; If this timing point is used the
7226 corresponding heuristics is called during the pricing loop of variables; we also added this timing point to
7227 heur_simplerounding.{h,c} which has the effect that a LP solution which satisfies all integrality conditions during
7228 the pricing loop is detected
7231 - added first version of an interface to NLP solvers (type_nlpi.h, struct_nlpi.h, nlpi.h, nlpi.c, nlpi_oracle.h, nlpi_oracle.c)
7232 - Preliminary support of non-convex MIQCPs: Constraint handler for quadratic constraints, NLP heuristic and
7233 Ipopt interface, see \ref cons_quadratic.h.
7234 - There are LP-interfaces to QSopt and Gurobi (rudimentary).
7237 - added reader and writer for FlatZinc models (reader_fzn.{c,h})
7238 - added writer for GAMS models (reader_gms.{c,h})
7240Performance improvements
7241------------------------
7243- Enhanced MCF cuts: stable version, used by default
7244- replaced some function calls in loop conditions
7245- in sepa_cmir.c, if mksetcoefs is invalid for delta=1 no other values of delta are tested anymore
7246- changed the timing of the feasibility pump in case of pricing
7247- removed changing of update rule to `ETA` from standard soplex update `Forrest-Tomlin` in lpi_spx.cpp
7248- improved memory usage in heur_octane.c
7249- improved reading time of opb-files, due to using a hashtable for all `and`-constraints
7250- improved performance of merging variables in mergeMultiples() in cons_knapsack.c
7251- improved performance in tightenWeightsLift() and SCIPseparateRelaxedKnapsack() in cons_knapsack.c, due to now
7252 sparse-cleaning `global` arrays instead of using BMSclearMemory... functions for cleaning local arrays each time
7253- improved performance in SCIPcliquelistRemoveFromCliques()
7254- improved performance in SCIPcalcCliquePartition()
7255- improved performance in SCIPvarGetActiveRepresentatives() in var.c
7258 - improved pairwise presolving in cons_and.c due to using a hashtable
7259 - improved pairwise presolving in cons_xor.c due to using a hashtable
7264- A significant change for C++ users is that all include files of SCIP
7265 automatically detect C++ mode, i.e., no `extern `C`` is needed anymore.
7266- Reader for Flatzinc and GAMS models
7268### New and changed callbacks
7270- The callback SCIP_DECL_PRICERREDCOST(x) in the \ref PRICER `pricers` has two new parameters:
7271 + A `result` pointer determines whether the pricer guarantees that there exist no more variables. This allows for early branching.
7272 + A pointer for providing a lower bound.
7274- The \ref CONS `constraint handlers` have two new callback methods (see type_cons.h for more details):
7275 + SCIP_DECL_CONSCOPY(x): this method can be used to copy a constraint.
7276 + SCIP_DECL_CONSPARSE(x): this method can be used to parse a constraint in CIP format.
7278### Deleted and changed API methods
7280- SCIPcalcMIR() in scip.h has two new parameter `mksetcoefsvalid` and `sol`. The parameter `mksetcoefsvalid` stores
7281 whether the coefficients of the mixed knapsack set (`mksetcoefs`) computed in SCIPlpCalcMIR() are valid. If the mixed
7282 knapsack constraint obtained after aggregating LP rows is empty or contains too many nonzero elements the generation of the
7283 c-MIR cut is aborted in SCIPlpCalcMIR() and `mksetcoefs` is not valid. The input parameter `sol` can be used to separate a
7284 solution different from the LP solution.
7285- new parameter `set` in SCIPconsSetInitial().
7286- some interval arithmetic method take an additional argument to denote which value stands for infinity in an interval
7289 - SCIPgetVarClosestVlb() and SCIPgetVarClosestVub() in scip.h have a new parameter `sol`. It can be used to obtain the closest
7290 variable bound w.r.t. a solution different from the LP solution.
7291 - new parameters `lowerbound` and `result` in type_pricer.h: lowerbound can save a lower bound computed by the pricer,
7292 result indicates whether the pricer guarantees that there exist no more variables if no variable was found
7294### New API functions
7296- new methods to deactivate a pricer SCIPdeactivatePricer() in scip.c
7297- new methods in pub_misc.h/misc.c to access hash map lists and elements of a hash map list and to clear all entries in a hash map
7298- SCIPsetProbName() to set problem name in scip.h/c (SCIPprobSetName() in prob.h/c)
7301 - SCIPgetTransObjscale() and SCIPgetTransObjoffset() in scip.c
7302 - SCIPaddObjoffset() in scip.h; sets offset of objective function
7303 - SCIPgetOrigObjoffset() in scip.h; returns the objective offset of the original problem
7304 - SCIPgetOrigObjscale() in scip.h; returns the objective scale of the original problem
7307 - detectRedundantConstraints() in cons_xor.c and necessary hash-functions for fast pairwise presolving
7308 - SCIPparseCons() in scip.h; parses constraint information (in cip format) out of a string
7309 - SCIPgetConsCopy() in scip.h; which copies a constraint of the source SCIP
7312 - SCIPisLPRelax() and SCIPisRootLPRelax() in scip.c and scip.h returning whether the current/root LP is a
7313 relaxation of the current/root problem and thus defines a valid lower bound
7314 - SCIPlpSetIsRelax() and SCIPlpSetRootLPIsRelax() in lp.c and lp.h to set the information, whether the lp is a valid relaxation;
7315 this information is per default set to true and constraint be used. The aggregated version has only 2 linear constraints the
7316 default linearization has nvars + 1
7319 - extended the sort template functions in sorttpl.c with a `five` array; now it possible to used this template to sort
7321 - new interface methods SCIPcolSort(), SCIProwSort(), SCIPcolGetIndex()
7322 - added SCIPsortPtrPtrLongInt() and corresponding sorting/inserting/deleting methods in pub_misc.h and necessary defines
7326 - SCIPprintNodeRootPath() in scip.h This method prints all branching decisions on variables from the root to the given node
7327 - SCIPnodeGetParentBranchings(), SCIPnodeGetAncestorBranchings(), SCIPnodeGetAncestorBranchingPath(); These methods return
7328 the set of variable branchings that were performed in the parent node / all ancestor nodes to create a given node
7329 - SCIPchgVarLbLazy() and SCIPchgVarUbLazy() in scip.h; These methods can be used to change the lazy lower or
7330 upper bound of a variable; This might has the consequences that the bounds of the corresponding variable is not in
7331 LP. This is the case if the lazy lower or upper bound is greater or less than the local lower or upper bound, respectively
7332 - SCIPvarGetLbLazy() and SCIPvarGetUbLazy() in pub_var.h; These methods return the lazy lower or upper bound, respectively
7333 - SCIPvarCompareActiveAndNegated() and SCIPvarCompActiveAndNegated() in pub_var.h for comparing variables
7334 negated, active or fixed the same way
7335 - SCIPparseVars() in scip.h; parses variable information (in cip format) out of a string
7336 - SCIPgetNFixedonesSetppc() and SCIPgetNFixedzerosSetppc() in cons_setppc.{h,c}; these methods returns
7337 current (local) number of variables fixed to one/zero in the given setppc constraint
7338 - SCIPgetVarConflictlengthScore(), SCIPgetVarAvgConflictlength(), SCIPgetAvgConflictlengthScore() and their pendants for the current run
7339 - added function SCIPvarsGetProbvarBinary() in pub_var.h; gets active, fixed, or multi-aggregated problem variables of
7340 binary variables and corresponding negated status
7342### Interfaces to external software
7345 - heavily revised Mosek interface
7346 - new interface to QSopt due to Daniel Espinoza
7347 - First version of LP interfaces to Gurobi and QSopt
7348 - Major performance improvements in LP interfaces to Clp, Mosek and SoPlex
7351 - adjusted interface to ZIMPL (reader_zpl.{c,h} for ZIMPL version 2.10; this interface should also work with older ZIMPL versions
7352 - Adjusted interface to Zimpl version 3.0.0
7353 - added first version of an interface to Ipopt (only QCP, no deletion of vars/cons allowed; nlpi_ipopt.(h|c))
7356 - On http://code.google.com/p/python-zibopt/source/checkout you find a beta
7357 version of a python interface to SCIP implemented by Ryan J. O'Neil.
7359### Changed parameters
7361- removed parameter `constraints/and/initiallp` since it is not needed anymore;
7362- set parameter `constraints/and/sepafreq` default value to 1
7363- display character of oneopt heuristic changed to `b`
7367- `branching/relpscost/advanced/conflenscore`, default value 0.001
7368- `constraints/and/aggrlinearization` in cons_and.c, aggregated version of the linearization
7369- `constraints/and/enforcecuts` in cons_and.c, should cuts be separated during LP enforcing?
7370- `constraints/and/presolusehashing` in cons_and.c, should pairwise presolving use hashing?, default TRUE
7371- `constraints/countsols/sollimit` in cons_countsols.c, counting stops, if the given number of solutions were found (-1: no limit)
7372- `constraints/xor/presolusehashing` in cons_xor.c, should pairwise presolving use hashing?, default TRUE
7373- `heuristics/oneopt/duringroot`, default value TRUE
7380- extend Makefile to link against Ipopt if `IPOPT=true` is set
7385- fixed wrong use of pointer in lp.c
7386- fixed bug with array dimension not reset to zero when array is freed in pseudoobj propagator
7387- fixed bug with enforcement of pseudo solutions: if pseudo solution is choosen because LP hit a limit, it has to be
7388 enforced in any case
7389- fixed potential bug in coloring example: SCIPcreateChild() is now given an estimate in terms of the transformed
7390 problem by SCIPgetLocalTransEstimate(), no longer the estimated original problem value. Also clarified this in the
7391 comments for SCIPcreateChild()
7392- fixed compiler warning `warning: dereferencing type-punned pointer will break strict-aliasing rules` which resuts in
7393 scip-crashes with gcc version 4.4.0
7394- adjusted assert in var.c
7395- fixed bug in SCIPvarGetActiveRepresentatives() in var.c
7396- fixed bug with objective limit in lp.c: previously the infinity value of SCIP was used as default - now the value of
7397 LPI is used. In the earlier version in many cases the problems where never infeasible.
7398- added and adjusted some asserts, initialized some values
7399- increased the numerical stability of coefficient tightening for Big M formulations
7400- fixed bug with incorrect pseudo activities when objective of a variable switches sign in linear constraint handler
7401- fixed bug with empty constraints in several writing routines
7402- fixed `GGT-Kaibel-Bug` in var.c, prop_pseudoobj.c and cons_varbound.c that occured while computing new values using
7406 - fixed bug in coefficient tightening with infinite bounds
7407 - fixed bug in solve.c: in case lowerbound >= upperbound, SCIPsolveIsStopped() returned `SCIP_STATUS_GAPLIMIT`
7410 - fixed bug in SCIPsolveNode() concerning the case that the time limit was hit while solving the LP relaxation of a
7411 subproblem which is already an LP (branching on pseudo solution is not possible)
7412 - fixed bug in vbc tools concerning of marking probing nodes
7413 - fixed bug in solve.c with nodes which are marked to be repropagated while enforcement
7416 - fixed possible infinite loop while multiaggregating a variable in var.c
7417 - fixed bug in SCIPgetSolVals() similar to SCIPgetSolVal(): try to get original variables of transformed ones if the
7418 solution lives in original space
7421 - fixed potential bug: restarts are now only done if no active pricers exist
7422 - fixed bug in SCIPlpSolveAndEval(): if fastmip and pricers enabled and objlimit was reached but CPLEX did not perform
7423 the final pivot step in order to exceed the objlimit, do one additional simplex step with pricing strategy steepest
7424 edge, if this doesn't suffice, turn off fastmip temporarily and solve again. Also consider solstat of the new
7426 - fixed bug with invalid pseudo solution (lower bound was always >= 0) when using pricing.
7427 - fixed bug in SCIPfreeProb() in scip.c: all pricers are deactivated now
7430 - now frees debug memory
7431 - fixed bug with exponential complexity for reallocating memory in SCIPvarGetActiveRepresentatives() in var.c
7432 - fixed casting of void* pointers in memory.h for C++, adjusted the same for C in memory.h and due to that adjusted all
7433 header files(set whole files in extern `C`) and cpp-files(removed unnecessary extern `C` lines)
7434 - removed memory leak in connection with freeing branch and bound nodes: focusnode was not freed if both children could
7435 be cut off due to bounding
7437- Reading and Writing:
7438 - corrected bug in reader_lp.c: earlier read bounds were thrown away (implementation was not conforming to standard)
7439 - fixed bug in reader_lp.c with respect to constraint and variable names which start with two or more dots `..`
7440 - fixed bug in all readers w.r.t. SCIPgetProbvarLinearSum()
7441 - fixed bug in reader_mps.c with respect to corrupted files
7442 - fixed bug in reader_mps.c with respect to writing transformed problems
7443 - changed wrong writing of mps files due to constraints without any name
7444 - fixed a bug during reading debug solution file
7445 - fixed bug in case of reading an objective function in opb format with multiple occurrences of the same variable
7446 - fixed bug in case of reading an objective function in lp format with multiple occurrences of the same variable
7447 - fixed a wrong fix of a reading bug, which was in reality a writing bug in MPS format; integer variables in mps format
7448 without bounds are binary variables, if the bound of an integer variable is infinity you have to write this bound
7451 - fixed bug in sepa_cmir.c, sepa_mcf.c and sepa_flowcover.c: sol different to LP solution is now separated
7452 - corrected two asserts in sepa_redcost.c (reduced costs can be negative for fixed variables: qsopt uses this)
7453 - fixed bug in sepa_zerohalf.c; replacement of own sorting functions by template functions was incorrect
7454 - fixed bug in var.c, cons_knapsack.c and sepa_flowcover.c: variable bounds corresponding to implication are not
7455 generated if coefficient is large, variable bounds with large coefficients are ignored for construction of knapsack
7457 - fixed bug in sepa_impliedbound.c concerning redundant implications
7460 - fixed bug in sepa_cmir.c concerning uninitialized mksetcoefs (if MIR-cut generation is aborted because the aggregated
7461 constraint is empty or contains too many nonzero elements mksetcoefs is invalid)
7462 - interrupts optimization process if a node will be cutoff, which allows the solution
7463 - fixed bug in sepa_impliedbounds.c and sepa_intobj.c: if separating a sol, this sol is now also given to SCIPaddCut()
7464 so that the efficacy of the cut is now computed correctly
7465 - fixed bug in solve.c caused by integer overflow due to setting the number of cuts to INT_MAX
7468 - fixed wrong result in check.awk, if infeasible problems are stopped in presolving
7469 - fixed exponential calculation of solution values during check of original solution, therefore changed
7470 SCIPvarGetActiveRepresentatives() in var.c and flattened all multiaggregated vars at the end of presolving in
7472 - fixed bug with wrong abort criterion in presolving
7473 - fixed bug in presol.c caused by not reseting presolver-wasdelayed status
7474 - fixed bug in SCIPconsSetInitial() that occurred in pairwise presolving: add or delete constraint in initconss when
7475 changing the initial flag
7478 - fixed bug in cons.c caused by not resetting conshdlr data after restart
7479 - fixed memory error in cons_countsols.c
7480 - fixed assert in cons_and.c method SCIP_DECL_CONSINITSOL(consInitsolAnd)
7481 - fixed bug in cons_countsols.c we respect to warning message that `The current parameter setting might cause ...`
7483- Knapsack Constraint Handler:
7484 - fixed wrong assert in cons_knapsack.c and handled a special this case in simplifyInequalities()
7485 - fixed some bugs in simplifyInequalities() in cons_knapsack.c
7486 - fixed bug in mergeMultiples() in cons_knapsack.c
7487 - adjusted ConsData and ConsHdlrData in cons_knapsack.c
7488 - fixed compiler warning caused by no initialization of two integer in cons_knapsack.c
7489 - fixed bug in cons_knapsack.c caused by having a multi-aggregated variable in a knapsack constraint, now applyFixing is
7490 able to resolve a binary multi-aggregation with integral values
7492- Linear Constraint Handler:
7493 - fixed infinity loop in simplify inequalities in cons_linear.c
7494 - fixed bug in cons_linear.c: do not select variable as slack variable for multiaggregation in convertLongEquality if it
7495 has been marked as not-multiaggregable
7496 - fixed bug in cons_linear.c: also do not multiaggregate variables in dual preproccessing if it has been marked as
7498 - fixed bug in cons_linear.c: slight decrease of epsilon in order to make sure that scaled coefficients are really
7500 - fixed bug in chgRhs() and chgLhs() of cons_linear.c: after changing lhs or rhs of a constraints lhs <= rhs has to be
7501 satisfied without numerical tolerances
7504 - added and changed some SCIPisStopped() calls in several heuristics
7505 - fixed bug in oneopt heuritic with start solution which has become infeasible due to global bound changes
7508 - corrected several bugs in the Clp-interface concerning return values
7509 - fixed potential interface bug: time limits of 0.0 are not anymore passed to the LP solver, which may have caused
7512@page RN1_1 Release notes for SCIP 1.1
7514@section RN110 SCIP 1.1.0
7515*************************
7520- SCIP can now count integer feasible solutions for IPs/CIPs (without continuous variables) (see SCIPcount())
7521- check.awk now uses TeX package supertabular which supports automatic pagebreak
7522- struct `SCIP_Stat` has now two additional variables: `nprobboundchgs`, `nprobholechgs`; these are used to fix the domain
7523 reduction counts in sepa.c, cons.c, branch.c and prop.c; this means, that now the domain reduction counts are reduced
7524 by those domain reduceds which are preformed during probing
7525- added capabilities to flatten the (multi)-aggregation graph of variables
7526- pseudoobj propagator now also propagates the global lower (dual) bound
7527- new heuristic DINS (distance induced neighborhood search by Ghosh)
7530 - SCIP can now output a picture of the constraint matrix in PPM format.
7531 - output of real values is now done with 15 digits after the decimal point
7532 - Extended the capabilities of SCIP to output problems in different formats (LP, MPS, CIP, ...). You can output the original and
7533 transformed problem. Furthermore, generic names can be given to the variables and constraints.
7534 - The feasibility test for solutions at the end of the execution now outputs more useful information.
7535 This made some changes in the interface of constraint handlers necessary.
7538 - added predefined settings file presolving/aggressive.set
7539 - new presolver boundshift (presol_boundshift.{c,h}); this presolver is currently turned off with default parameter setting
7542 - linear constraint handler now detects continuous variables that are implicit integer in dual presolve
7543 - replaced some old sorting methods in cons_knapsack.c, heur_octane.c, sepa_flowcover.c and presol_probing.c through
7544 SCIPsort...() interfaces, adjusted misc.{c,h} and pub_misc.h for these changes
7545 - cons_countsols.c is now able to store the collected solution if required
7546 - added first version of SOS type 1 constraint handler (cons_sos1.{c,h})
7547 - added first version of SOS type 2 constraint handler (cons_sos2.{c,h})
7548 - less aggressive scaling in linear constraint handler presolve to improve numerics
7549 - added first version of constraint handler cons_countsols.{c,h}
7552 - added ccg-reader (weighted column connectivity graph)
7553 - added reader for pseudo-Boolean problems (reader_opb.{c,h})
7554 - the ZPL reader is now able to pass a starting solution to SCIP
7555 - the MPS reader is now able to write a problem in MPS format
7556 - the ZIMPL reader now understands SOS type 1 and 2 constraints
7557 - the LP reader reads SOS constraints of type 1 and 2
7558 - the MPS reader reads the SOS section (but cannot yet handle `MARKERS`)
7561 - The SoPlex LPI can now write basis files.
7562 - revised lpi_clp.cpp (many small changes, in particular writing and reading of bases)
7563 - added FASTMIP settings in lpi_clp.cpp that try to improve the performance of Clp as much as possible
7565- Cuts and Separation:
7566 - the c-MIR separator now also tries to get rid of implicit integer variables by aggregation
7567 - allow cut selection based on support of inequality in orthogonality computation
7568 - disabled zerohalf cuts by default
7569 - adjusted all predefined settings files, e.g., `settings/cuts/fast.set`, such that they are consistent wrt removed,
7570 added and changed parameter values of scip.
7571 - New cutting plane separator MCF (beta version).
7572 - new separator sepa_zerohalf.{c,h}; separates {0,1/2}-Cuts according to Caprara and Fischetti
7574Performance improvements
7575------------------------
7577- heavily decreased the usage of SCIPisStopped(), which costs system time
7578- small performance improvement of c-MIR aggregation heuristic
7579- reworked strong branching in lpi_clp.cpp (scaling works now, bounds can be trusted)
7582 - The preprocessing has been revised. It now applies bound computations in a numerically more stable way. The pairwise
7583 comparison of linear, logicor, and setppc constraints has been improved.
7584 - better branching in SOS1/SOS2 constraints
7585 - fixed performance bug with large number of unnamed constraints that will kill the name hash table (now, unnamed
7586 constraints are not put into the hash table)
7588- Cuts and Separation:
7589 - improved the performance of SCIPcalcMIR() and SCIPcalcStrongCG() by exploiting sparsity
7590 - improved performance of SCIPvarGetLPSol(), which affects many parts of the code, in particular Gomory and strong CG cuts
7591 - do not calculate MIR and StrongCG cut aggregations if number of nonzeros in aggregated row is too large
7594 - improved pairwise presolving in cons_linear.c: reduced cache misses, reduced number of SCIPisStopped() calls and
7595 included detecting of redundant constraints with hash table in advance
7596 - tighter memory limits in knapsack presolve lifting procedure to avoid overly expensive presolving
7597 - included detecting of redundant constraints with hash table in advance in cons_logicor.c and limit other pairwise
7599 - included detecting of redundant constraints with hash table in advance in cons_setppc.c and limit other pairwise
7601 - limit pairwise presolving in cons_linear.c
7603Examples and applications
7604-------------------------
7606- Added an example for the graph coloring problem in `examples/Coloring`, showing the usage of column generation.
7608- extended TSP example
7613### New and changed callbacks
7615- New callback method SCIP_DECL_READERWRITE(x) in type_reader.h; this method is called to write a problem to file
7616 stream in the format the reader stands for; useful for writing the transformed problem in LP or MPS format. Hence,
7617 also SCIPincludeReader() has changed.
7618- The callback \ref CONSCHECK (SCIP_DECL_CONSCHECK()) in the constraint handlers now has a new parameter `printreason` that tells
7619 a constraint handler to output the reason for a possible infeasibility of the solution to be checked using
7620 SCIPinfoMessage(). Have a look at one of the constraint handlers implemented in SCIP to see how it works. This
7621 methodology makes it possible to output the reason of a violation in human readable form, for instance, for the check
7622 at the end of a SCIP run, where the obtained best solution is checked against the original formulation.\n This change
7623 often has little effect on C-implementations, since this parameter can be safely ignored with respect to the
7624 correctness of the code. The corresponding C++ method scip::ObjConshdlr::scip_check(), however, has to be extended
7625 and will not compile otherwise.
7626- added new LPI pricing option `SCIP_PRICING_LPIDEFAULT`, such that every LP interface can set the default pricing
7627 strategy on its own (`auto` is not useful for this, because for CPLEX, for example, SCIP seems to be worse with `auto`
7628 then with `steepest edge`)
7629- Added user pointer to callback methods of hash table, see pub_misc.h.
7631### Deleted and changed API methods
7633- SCIPgetVarRedcost() now returns 0 for variables that have been aggregated out or removed in presolving.
7634 reduced cost in case of infeasible LPs)
7635- new parameter `maxfrac` for SCIPcalcStrongCG()
7636- new parameter `maxmksetcoefs` for SCIPcalcMIR() and SCIPcalcStrongCG() methods
7637- new parameter `conshdlrname` in SCIPincludeLinconsUpgrade()
7640 - new parameters `extension` in SCIPreadProb() defining a desired file format or `NULL` if file extension should be use
7641 - New parameters `extension` and `genericnames` in SCIPprintTransProblem(), SCIPprintOrigProblem(),
7642 SCIPwriteOrigProblem(), and SCIPwriteTransProblem() defining the requested format or `NULL` for default CIP format
7643 and using generic names for the variables and constraints. Examples are
7644 - SCIPprintTransProblem(scip, NULL, NULL, TRUE) displays the transformed problem in CIP format with
7645 generic variables and constraint names
7646 - SCIPprintOrigProblem(scip, NULL, `lp`, FALSE) displays the original problem in LP format with
7647 original variables and constraint names.
7650 - expand sorttpl.c by some parameters
7651 - changed some names for sorting methods
7652 - replaced sorting methods SCIPbsort...() by faster (quicksort/shellsort) algorithms SCIPsort...() Note that the order
7653 of the parameters has been changed to simplify the template code in sorttpl.c!
7656 - SCIPcheckSolOrig() is restructured. The last two parameters have changed. They are now bools indicating
7657 whether the reason for the violation should be printed to the standard output and whether all violations should be
7658 printed. This reflects the changes in the constraint handlers above, which allow the automation of the feasibility
7659 test. The pointers to store the constraint handler or constraint are not needed anymore.
7660 - the parameter list of the method SCIPcheckCons() (scip.h) has changed; the new advatage is, that SCIP can print the
7661 reason for the violation of a constraint as for as the constraint handler supports that
7662 - the parameter list of the method scip_check() (objconshdlr.h) has an additional parameter `printreason` see for
7663 explanation the previous point
7665### New API functions
7667- LPI now has a function SCIPlpiGetSolverPointer() that returns a solver dependent pointer. This can be used to directly
7668 access the LP solver. This should, of course, only be used by people that know exactly what they are doing.
7669- added capabilities to avoid multi-aggregation of a single variable by setting a corresponding flag (SCIPmarkDoNotMultaggrVar())
7670- SCIPgetProbvarLinearSum()
7671- SCIPgetResultantAnd() which returns the resultant variable of an `and` constraint
7672- SCIPchgChildPrio() to change the node selection priority of the given child
7674- SCIPrepropagateNode() to mark a node for repropagation
7675- SCIPcount() (in cons_countsols.h) for counting all feasible solution of a given CIP
7676- SCIPcreateRootDialog() (in dialog_default.h) which creates a root dialog
7677- SCIPgetVectorEfficacyNorm()
7678- SCIPseparateRelaxedKnapsack() in cons_knapsack.h
7679- SCIPgetCutoffdepth() which returns the depth of first node in active path that is marked being cutoff
7680- SCIPflattenVarAggregationGraph()
7681- SCIPclockGetLastTime()
7682- SCIPcalcHashtableSize() to get a reasonable hash table size
7683- SCIPgetVarFarkasCoef() and SCIPgetColFarkasCoef() to get the farkas coefficient of a variable (analogon of
7684- SCIPgetRepropdepth() to get the depth of first node in active path that has to be propagated again
7685- SCIPmajorVersion(), SCIPminorVersion() and SCIPtechVersion() returning the corresponding version
7687- Read, Write and Print:
7688 - SCIPprintSysError() which encapsulates the strerror_r calls, the NO_STRERROR_R flag switches between the use
7689 of strerror_r and strerror inside
7690 - SCIPsnprintf() safe version of snprintf (and sprintf)
7691 - SCIPreaderCanRead() and SCIPreaderCanWrite() in pub_reader.h, these return TRUE if the corresponding
7692 reader is capable to read or write, respectively
7693 - SCIPwriteOrigProblem(), e.g., SCIPwriteOrigProblem(scip, `orig.lp`, NULL, FALSE) prints the original
7694 problem in LP format in the file `orig.lp`
7695 - SCIPwriteTransProblem(), e.g., SCIPwriteTransProblem(scip, NULL, NULL, FALSE) displays the transformed problem in CIP format
7698 - SCIPcutGenerationHeuristicCmir() in sepa_cmir.h
7699 - SCIPheurGetTimingmask() and SCIPheurSetTimingmask()
7702 - added some downwards-sorting methods
7704 - SCIPsortedvecInsert...(), SCIPsortedvecInsertDown...(), SCIPsortedvecDelPos...(),
7705 SCIPsortedvecDelPosDown...(), SCIPsortedvecFind...() and SCIPsortedvecFindDown...() to manage sorted vectors or
7706 groups of vectors of various data types that are sorted w.r.t. the first vector
7708### Command line interface
7710- advanced reading and writing dialog in interactive shell
7712### Interfaces to external software
7714- Many changes in the SoPlex interface: The current one is tailored towards SoPlex 1.4 (aka 1.3.3). All SoPlex functions
7715 (where applicable) should now have an exception handling. The Bugfix for adding columns has been moved to SoPlex. One
7716 can use ROW representation. Reading/writing of a basis has been implemented.
7718### Changed parameters
7720- changed default frequency parameters for RINS, Local Branching, Crossover and Mutation heuristic This should not
7721 change the performance but happened just for consistency reasons
7722- changed parameter default values for the priority of presolver `dualfix` and `inttobinary`
7723- removed parameter `separating/cmir/maxtestdeltaroot`
7724- new value `l` for parameter `lp/pricing`, which is the new default
7728- `constraints/and/linearize` to enable linearization of all <and> constraints (in presolving),
7729- `constraints/and/initiallp` to turn on, off, or `auto` that the LP relaxation of the AND constraints are in the initial LP;
7730- `constraints/countsols/collect` to enable the storing of the solutions; default value FALSE;
7731- `constraints/indicator/addCoupling` to enable generation of relaxation
7732- `constraints/indicator/branchIndicators` to decide whether it is branched on indicator constraints in enforcing
7733- `constraints/indicator/genLogicor` to decide whether logicor constraints instead of cuts are generated
7734- `constraints/indicator/sepaAlternativeLP` to decide whether separation takes place using the alternative LP
7735- `constraints/linear/aggregatevariables` to search for aggregations in equations in the presolving step
7736- `constraints/linear/dualpresolving` to disable dual presolving step in the linear constraint handler; default value is TRUE
7737- `constraints/linear/simplifyinequalities` to enable a simplification step for inequalities; default value is set to FALSE = disabled
7738- `constraints/linear/upgrade/binpack` to enable or disable the linear upgrading process
7739- `constraints/linear/upgrade/eqknapsack` to enable or disable the linear upgrading process
7740- `constraints/linear/upgrade/invarknapsack` to enable or disable the linear upgrading process
7741- `constraints/linear/upgrade/knapsack` to enable or disable the linear upgrading process
7742- `constraints/linear/upgrade/logicor` to enable or disable the linear upgrading process
7743- `constraints/linear/upgrade/setppc` to enable or disable the linear upgrading process
7744- `constraints/linear/upgrade/varbound` to enable or disable the linear upgrading process
7745- `constraints/linear/presolusehashing` to use hashing comparison in cons_linear.c; default value is TRUE
7746- `constraints/logicor/presolusehashing` to use hashing comparison in cons_logicor.c; default value is TRUE
7747- `constraints/setppc/presolusehashing` to use hashing comparison in cons_setppc.c; default value is TRUE
7748- `constraints/SOS1/branchNonzeros` to decide whether SOS1 constraint with largest number of nonzero variables is picked for branching
7749- `constraints/SOS1/branchSOS` to enable or disable branching on SOS1 constraints
7750- `heuristics/feaspump/beforecuts` to allow the feaspump to be called before cut separation
7751- `heuristics/mutation/minimprove`
7752- `presol/donotmultaggr` which disables multiaggregation for all variables of the problem
7753- `separating/cmir/densityoffset` to allow for more c-MIR cuts on small models
7754- `separating/orthofunc` to choose function for scalar product computation in orthogonality test
7759- updated mmm.{test,solu}, mittelmann.{test,solu}, miplib3.solu, miplib.solu, shortmiplib.test and added
7760 mittelmann_current.test, mittelmann_old.test
7761- added test scripts for testing counting (make testcount)
7762- removed tag make testpre (useless without corresponding scripts)
7763- added tag testcount (make testcount); this allows for testing counting problem
7764- replaced tcsh by bash and gawk by awk in all check scripts to achieve higher compatibility
7771- added `make/make.project` as default make include for external projects using SCIP
7772- added possibility to compile shared libraries in makefiles (and added `make/make.linux.x86.gnu.opt-shared`)
7773- replaced <string> by <cstring> in all C++-interfaces to get `strlen()` included (gcc-4.3 gave an error)
7774- Moved -rpath option for ld to linux-specific Makefiles.
7775- Re-activated readline library on darwin/ppc.
7778 - added in all `make/make.*` `GMP_FLAGS` and `GMP_LDFLAGS`
7779 - new flag GMP with values (`auto`, `true and `false`); in case of `auto` the library gmp is linked if ZIMPL is
7781 - adapted all makefiles of the examples accordingly
7784 - modified makefiles to accept ZIMPLOPT and LPSOPT flags (with values `opt` or `dbg` and default being `opt`), and
7785 removed `LPS=spxdbg` and `LPS=clpdbg`
7786 - added target spx132 for SoPlex version 1.3.2
7791- fixed CTRL-C if NO_SIGACTION is set (e.g., for MinGW)
7792- added checks whether a plugin (handler) has already been included to avoid later complications e.g. with parameters.
7793- fixed bug with wrong `tightened` return value of some of the change bounds methods
7794- forced full propagation in presolving -> this fixes a bug that implied that variable locks became inconsistent
7795- replaced calls to perror() by SCIP error message using strerror(errno); this avoids problems with the error output
7797- fixed bug in method SCIPgetProbvarLinearSum()
7798- fixed bug with errors occurring in sub-MIPs. Search is only aborted in dbg mode, in opt mode a warning will be printed
7799- fixed bug in tclique-graph datastructure concerning insertion of edges into nonempty graph
7800- corrected bug in SCIPtreeBranchVar() (tree.c): several comparison functions needed a `feas`.
7801- fixed bug in SCIPtightenVarLb/Ub() in scip.c concering forcing a bound change (bound improvement is checked now)
7802- improved stage checking for bound computation
7803- fixed usage of command test for string comparison in check-scripts (now compatible with ubuntu)
7804- replaced sprintf and snprintf by SCIPsnprintf() fixed potential bug with overlong strings
7805- corrected bug in the case when soplex threw an exception in autopricing
7806- fixed bug in SCIPvarGetOrigvarSum() concerning the corner case the a negated variable has no parent variable in
7810 - avoid aggregation of implicit integers with fractional aggregation scalars
7811 - fixed bug in aggregateActiveIntVars(): If a < 0, multiply a*x + b*y == c by -1 (algo for finding initial solution does
7812 only work for a > 0).
7813 - avoiding aggregation that removes information about implicitly integer variables (removes bug)
7814 - fixed bug with exponential running times due to complicated recursive multi-aggregation
7815 - corrected bug in var.c occuring during applying boundchanges in varUpdateAggregationBounds method
7818 - fixed bug that a missing CONSTRANS in constraint handler leads to `NULL` pointer as constraint data for the copied
7819 constraints instead of pointer copies of the consdata (as explained in the constraint handler `HowTo`)
7820 - fixed bugs in second part of consdataTightenCoefs(): Removed min/maxleftactisinfinity (definition was not correct),
7821 fixed calculation of min/maxleftactivity and removed asserts concerning whether all redundant vars were deleted (led
7822 to different behavior in debug and opt mod).
7823 - fixed typo in documentation: default value for `dynamic` parameter is FALSE for all constraint handlers!
7824 - fixed bug in preprocessing of SOS2 constraints (cons_sos2.c)
7825 - fixed bug in cons_countsols.c concerning variable locking
7826 - fixed bug in cons_varbounds.c, concerning SCIPaddVarVlb() and SCIPaddVarVub()
7827 - fixed bug in applyFixings() in cons_varbound.c concerning tightening the bound of a variable left in a redundant
7828 constraint (bound change is forced now)
7831 - fixed bug with useless objective cutoff in LNS heuristics
7832 - removed bug for values greater than (-)infinity, heur_shifting.c, heur_intshifting.c, heur_rounding.c, heur_oneopt.c
7833 - fixed bug with errors occurring in heuristic LPs. In opt mode a warning will be printed, abort in dbg mode
7835- Linear Constraints:
7836 - fixed bug with wrong update of activities in linear constraints after global upper bound changes
7837 - fixed bug in preprocessConstraintPairs() in cons_linear.c concerning updating the flags of the constraint that stayes
7838 in the problem (nonredundant information were lost before)
7839 - fixed bug in cons_linear.c caused by comparing two infinity values during checking of using variable as slackvariable
7840 - removed bug for rhs/lhs greater than (-)infinity, cons_linear.c
7841 - removed bug caused by hashcomparison for non-sorted constraints, cons_linear.c
7842 - fixed bugs with wrong presolving due to cancellation in (res-)activities in cons_linear.c
7843 - removed BOUNDSCALETOL adjustment in cons_linear.c. This fixes bug with slightly infeasible variable fixings in
7844 presolving; reliable resactivities should make the BOUNDSCALETOL relaxation redundant.
7845 - removed `epsilontic` bug in cons_linear.c due to adjusting left/right hand side in applyfixing
7846 - fixed bug with multi-aggregated variables in cons_logicor: instead of fixing them, a linear constraint will be created
7847 - corrected bug in cons_linear.c:applyFixings() [if variable was fixed to infinity the rhs/lhs were wrong]
7848 - fixed bugs in pairwise presolving of cons_linear.c concerning deletion of upgraded constraints and inconsistent update
7849 of nchgsides in case of coefsequal and coefsnegated
7850 - fixed false assert and corrected a bug caused by deleting a constraint on `firstchanged` position in pairwise
7851 presolving with hashing in cons_linear.c
7854 - fixed handling of unbounded variables with 0 objective in SCIPlpGetModifiedPseudo[Proved]Objval() (lp.c)
7855 - fixed bug with uncatched LPSOLSTAT after hitting a time or iteration limit
7856 - corrected bug in SCIPlpGetState() if the LP is empty
7857 - fixed bug in SCIPlpSolveAndEval(): added extra simplex step if objlimit reached, fastmip and pricers enabled in order
7858 to get dual solution for pricing.
7859 - weakened two too strong asserts in lp.c concerning the LP result OBJLIMIT
7860 - fixed bug in SCIPlpSolveAndEval(): allow more than one extra simplex step for getting an objlimit exceeding solution
7864 - corrected invalid memory access in tcliqueIsEdge: added check whether node1 has no neighbors (tclique_graph.c)
7865 - removed memory leak detected with the help of coverity in dialog.c
7866 - fixed bug with memory reallocation in SCIPgetProbvarLinearSum()
7867 - tried to fix memory leak in dialog.c occuring from different versions of the readline/history libraries
7868 - removed possible memory leak in objdialog.cpp
7871 - fixed numerical issue in linear constraint propagation: need slightly more aggressive tightening such that probing
7872 does not choose a wrong value for fixing inside an epsilon interval
7873 - fixed numerical bug in dual presolving of linear constraint handler
7874 - avoid fixing variables to infinity in order to get rid of numerical inconsistencies in the original model
7877 - added handling of the case of roundable variables with 0 objective in presol_dualfix.c
7878 - fixed bug with writing the MIP relaxation to a file concerning the objective function; in case the original objective
7879 function is requested, the transformed objective function gets re-transformed (scaling, offset)
7880 - fixed bug with wrong objective sense output for transformed problem. The transformed problem is always a minimization
7882 - fixed bug with objective scaling after restart
7885 - fixed bug with reading empty lines in TSP example
7886 - fixed bug with non-conformal parameter name in reader_ppm
7887 - fixed infinite loop in LP file reader if a line exceeds the character limit
7888 - fixed bug in reader_ppm while appending strings for output file
7889 - fixed some `SCIP_RETCODE` bugs in reader_fix.c, reader_sol.c, reader_sos.c and reader_zpl.c
7890 - fixed docu in type_reader.h
7891 - fixed bug with multi-aggregated variables which are de facto aggregated or fixed after flattening the aggregation tree
7892 - fixed bug with bound changes of variables in modifiable constraints during full dual presolving of linear conshdlr
7893 - increased compiler compatibility for C++ wrapper classed by adding extern `C` in obj*.cpp files and changing strlen
7894 calls to std::strlen
7897 - corrected bug in priceAndCutLoop(): separation was aborted if domain reduction was applied
7898 - fixed bug in sepa_mir.c: size of testeddeltas-array was too small
7899 - corrected imlementation of SCIPlpiGetBasisInd() in lpi_clp.cpp (this fixes the bug that almost no Gomory cuts are
7903 - fixed bugs in sorttpl.c: fixed wrong arraysize in shellsort; in case an has at most one element, then no sorting is
7905 - fixed wrong if condition for function call in sorttpl.c
7906 - fixed obvious bug in linear constraint data sorting. Most part of the code assumed pure index sorting, but in fact, it
7907 was sorted by variable type as first criterion and index as second criterion.
7909@page RN1_0 Release notes for SCIP 1.0
7911@section RN100 SCIP 1.0.0
7912*************************
7917- SCIP now has a couple of specialized settings, all called scip_*.set
7918- SCIP is now compatible to the Exception branch of SoPlex
7919- if possible, objective function is scaled to make objective value integral with gcd 1
7920- slightly modified automatic constraint aging strategy
7921- new C templates disp_xxx.h and dialog_xxx.h and C++ wrapper classes objdisp.h and objdialog.h, respectively
7922- modified reader `sol`, st. files which where created via typing the order of commands `set log *.sol`,
7923 `disp sol var -`, `set log cplex.log` in Cplex can now be read
7924- new dummy LP interface `lpi_none.c`; useful for running SCIP without a LP solver
7927 - modified probing presolver to do multiple cycles if called in subsequent runs
7928 - changed sort algorithm in probing presolver
7931 - new node selection rule `estimate` (best estimate search)
7932 - new node selection rule `hybridestim`
7935 - the doxygen documentation now has HowTo's for all plugin types
7936 - the doxygen documentation now contains a FAQ
7937 - the documentation has now a TAB Modules; there you can find list of available constraint handles, presolvers,
7938 propagators, lpi interfaces, file readers and so on
7941 - time limit is now forwarded to lp solving algorithm
7942 - presolving, cut separation, primal heuristics and strong branching now better respect time limit
7945 - best estimate search is now used in all large neighborhood search heuristics
7946 - new improvement heuristic `oneopt`
7947 - new heuristic `actconsdiving` following an idea of John Chinneck
7949- Separation and Cuts:
7950 - modified cut selection code
7951 - cut conversion into linear constraints after a restart now works better
7952 - added flow cover separator
7953 - gomory cuts are now also separated for integral slack variables
7954 - less aggressive in Gomory cut separation
7955 - strong CG cuts are now also separated for integral slack variables
7957Performance improvements
7958------------------------
7960- greatly improved performance of LP file reader by replacing string copies with pointer copies
7961- removed performance bottleneck with non-bfs based node selectors and large leaf queues at the cost of a small memory
7962 overhead (2 ints per node in the leaf queue); this improves performance quite a bit on instances that take a large
7963 number of branching nodes
7964- improved performance of linear constraint propagation by delaying some floor/ceil calculations
7965- improved performance of clique cut separator
7970### New and changed callbacks
7972- new callback method SCIPdialogFree()
7974### Deleted and changed API methods
7976- slightly modified bound substitution heuristic in SCIPcalcMIR() and SCIPcalcStrongCG()
7977- slightly less conservative in numerics for SCIPmakeRowIntegral()
7978- linear and knapsack constraint handler may now deal with coefficients of value zero
7979- new parameter `maxbounddist` for SCIPincludeSepa() and constructor ObjSepa()
7980- new parameter `restart` for method SCIPfreeSolve()
7981- calling SCIPwriteLP() is now possible in Solved Stage
7982- SCIPwrite{LP,MIP} may no longer be called after solving, since the LP data structures may not be valid
7983- All functions SCIP<datatype>Param() got a new parameter `isadvanced`.
7984 This does not influence the performance of SCIP, but the position of the parameter in the settings menu.
7985 Hence, if you do not care about this, you can assign any value to it.
7986 You should add the corresponding flag to the SCIP<datatype>Param() calls in your own source code.
7989 - modified `SCIP_SUBVERSION` to be a number instead of a string (to be able to use `SCIP_SUBVERSION >= ...`)
7990 - SCIPsubversion() now returns an int instead of a const char*
7993 - new parameter `estimate` for SCIPcreateChild() giving an estimate for value of best feasible solution in the subtree to
7994 be created. One possibility is to use SCIPgetLocalOrigEstimate() for this value.
7995 - removed method SCIPnodeGetPriority()
7996 - removed parameter `lowestboundfirst` from SCIPincludeNodesel()
7999 - removed parameter `branchdir` from SCIPbranchVar()
8000 - new parameters `leftchild`, `eqchild` and `downchild` for SCIPbranchVar()
8001 - SCIPgetVarStrongbranch() now also returns lperror == TRUE if the solving process should be stopped, e.g., because of a
8004- Variable tightening:
8005 - replaced methods SCIPvarGetClosestVlb() and SCIPvarGetClosestVub() from pub_var.h by new methods
8006 SCIPgetVarClosestVlb() and SCIPgetVarClosestVlb() in scip.h
8007 - new parameter `force` for SCIPtightenVarLb() and SCIPtightenVarUb()
8009### New API functions
8013- SCIPgetLocalOrigEstimate() and SCIPgetLocalTransEstimate()
8015- SCIProwIsInGlobalCutpool()
8017- SCIPgetVarRedcost()
8018- SCIPtightenVarLbGlobal() and SCIPtightenVarUbGlobal()
8019- SCIPsepaGetMaxbounddist()
8020- SCIPboundchgGetNewbound(), SCIPboundchgGetVar(), SCIPboundchgGetBoundchgtype(),
8021 SCIPboundchgGetBoundtype(), SCIPboundchgIsRedundant(), SCIPdomchgGetNBoundchgs(), SCIPdomchgGetBoundchg()
8022- SCIPnodeUpdateLowerboundLP()
8023- SCIPcalcNodeselPriority()
8024- SCIPnodeGetEstimate()
8025- SCIPnodeGetDomchg()
8026- SCIPgetRootNode() (in combination with SCIPcutoffNode(), this allows the immediate finishing of the optimization)
8028### Command line interface
8030- default dialog menu now includes the commands `set default` and `display parameters`
8031- added option to write node LP and MIP relaxations to LP file from interactive shell
8033### Changed parameters
8035- parameters are now separated into basic and advanced, the latter ones have been moved to extra submenus
8036- priority parameters are now restricted to be in [INT_MIN/4,INT_MAX/4] to avoid overflow errors in comparison methods
8037- increased priority of `estimate` node selector, such that this is the new default node selector
8038- changed meaning of parameter setting `nodeselection/childsel = l`; old meaning is now called `r`
8039- changed default value of `conflict/maxvarsfac` to 0.1
8040- changed default value of `conflict/useprop` to TRUE
8041- changed default value of `conflict/useinflp` to TRUE
8042- changed default value of `conflict/usepseudo` to TRUE
8043- changed default value of `conflict/maxlploops` to 2
8044- changed default value of `conflict/lpiterations` to 10
8045- changed default value of `conflict/interconss` to -1
8046- changed default value of `conflict/reconvlevels` to -1
8047- changed default value of `conflict/settlelocal` to FALSE
8048- changed default value of `constraints/linear/propfreq` to 1
8049- changed default values of `heuristics/∗diving/backtrack` to TRUE
8050- changed default value of `nodeselection/restartdfs/stdpriority` to 10000
8051- changed default value of `numerics/boundstreps` to 0.05 in order to avoid very long propagation loops on continuous variables
8052- changed default value of `presolving/restartfac` to 0.05
8053- changed default value of `presolving/restartminred` to 0.10
8054- changed default value of `separating/objparalfac` to 0.01 for performance reasons
8055- changed default value of global `separating/maxbounddist` to 1.0
8056- changed default value of `separating/objparalfac` to 0.0001
8060- `conflict/enable` to globally enable or disable conflict analysis
8061- `constraints/linear/maxcardbounddist` and `constraints/knapsack/maxcardbounddist`
8062- `heuristics/∗diving/backtrack` to activate 1-level backtracking for most of the diving heuristics
8063- `heuristics/feaspump/maxstallloops`
8064- `nodeselection/childsel` to control the child selection
8065- `presolving/immrestartfac`
8066- `separating/∗/maxbounddist` to have individual maxbounddist parameters per separator
8067- `separating/clique/backtrackfreq` to speed up clique cut separation in heuristic fashion
8068- `separating/redcost/continuous`
8075- added version numbers to library files (There will be a softlink generated in the lib/ and bin/ directories without
8076 version number that point to the latest compiled version.)
8077- added .exe extension to binaries of MinGW
8078- removed the `.static` extension associated to the LINK variable from the Makefile system (If you want to build
8079 makefiles for shared library generation, use the OPT variable. For example, you could create a makefile
8080 `make/make.linux.x86.gnu.opt-shared` and compile it with `make OPT=opt-shared`.)
8082- Defaults and Options:
8083 - modified the default LP solver to be SoPlex instead of CPLEX
8084 - added `LPS=none` for compiling SCIP without a LP solver
8085 - made `ZIMPL=true` the default; if you do not want to include ZIMPL support, call `make ZIMPL=false`
8090- fixed bug in rowScale() concerning deletion of almost zero coefficients
8091- weakened assert in primal.c in order to avoid numerical troubles
8092- fixed bug with too long variable names
8093- fixed bug with strange user descriptions of plugins
8094- changed position of some asserts to prevent segmentation faults
8095- SCIPgetAvgPseudocostCount() and SCIPgetAvgPseudocostCountCurrentRun() now return the average over all integer
8096 variables instead of all variables, since pseudo costs are not recorded for continuous variables
8097- fixed wrong sorting of plugins with priorities close to INT_MIN or INT_MAX
8098- replaced `line` by `read` in Makefile, since `line` is non-standard
8099- fixed bug with branching rules that produce only one child with no changes to the problem
8100- fixed bug that external relaxator is not reset appropriately for a new problem instance
8101- removed wrong assert in function paramWrite()
8102- fixed bug with uninitialized in check.awk
8103- fixed bug in ZIMPL file reader for multiple occurrences of a single variable in the objective function
8104- fixed bug with deleting variables from the transformed problem that are contained in the implication graph
8105- fixed bug in root reduced cost fixing propagator that leads to an empty domain for a variable as a proof of optimality
8106 of the current incumbent
8107- fixed bug with fractional coefficients of binary variables in cont --> impl int upgrading
8110 - fixed bug with aggregated variables in debug solution test
8111 - now it is possible to add original solutions
8112 - fixed bugs with SCIPgetBestsol() returning `NULL` after a restart with user objective limit
8113 - fixed wrong status code in presence of user objective limit and a feasible solution that is not better than the limit
8116 - fixed bug with wrong bound changes of loose variables
8117 - changed wrong assert in SCIPnodeAddBoundinfer()
8118 - fixed bug in variable bounds search and insertion method
8119 - fixed bug regarding modifying bounds in original problem if negated original variables exist
8120 - fixed bug with multiple pending bound changes on some variable
8123 - fixed bug in integer objective separator with restarts
8124 - fixed bug in integer objective separator with dynamic columns
8127 - fixed bug that cut age was not reset to zero for violated cuts
8128 - fixed bug in SCIPcutpoolAddNewRow() concerning update of minidx and maxidx of added row
8129 - fixed numerical bug in rowScaling of lp.c, which possibly cut off feasible solutions
8130 - significantly improved performance of c-MIR and Gomory cuts by caching closest VLB and VUB info
8133 - fixed numerical buf with slightly different LP optimum after resolving due to probing/diving
8134 - fixed bug in cmir and flowcover separator with variables which are currently not in the LP
8135 - fixed bug with LP size management in probing if column generation is used
8136 - fixed bug in LP file reader with row names identical to section keywords
8137 - fixed potential bugs due to errors in resolving the LP after diving or probing
8138 - fixed potential bugs in SCIPpriceLoop() and priceAndCutLoop(), st. now all LP solution stati are handled appropriately
8139 - fixed potential bug with non-existent LP in SCIPwrite{LP,MIP}
8141- Constraint handler:
8142 - removed wrong assert in bounddisjunction constraint enforcement
8143 - fixed numerical bug in propagator of varbound constraint handler
8144 - fixed bug in variable bound constraint handler with changing bounds on multi-aggregated variables
8145 - fixed bug in linear constraint handler: only tight cuts are transformed into linear constraints after restart
8146 - fixed bug in bounddisjunction constraint handler with propagation of multi-aggregated variables
8147 - fixed bug with numerics in linear constraint handler due to non-representable `BOUNDSCALETOL`
8148 - fixed bug with almost integral multi-aggregation in dual presolve of linear constraint handler
8149 - fixed bug with numerics in update of min/maxactivity in linear constraint handler
8152 - fixed bug in intshifting and oneopt heuristic with variables which are currently not in the LP
8153 - fixed bug with primal heuristics reducing the cutoff bound such that the current node is cut off
8154 - fixed bug in oneopt heuristic: must not be called on pseudo nodes if continuous variables are present
8156@page RN0_9 Release notes for SCIP 0.9
8158@section RN090 SCIP 0.9.0
8159*************************
8164- the EXITSOL callback of the plugins is now called before the LP and the global cut pool are freed
8167 - new primal heuristics `rens`, `mutation` and `veclendiving`
8168 - primal heuristics that run before the node is solved now know already whether the LP will be solved at the current
8172 - new heuristic `intshifting` (ID character `i`)
8173 - in the root node of the very first run, heuristics with timing `AFTERNODELPNODE`, `AFTERLPPLUNGE`, `AFTERPSEUDONODE`, and
8174 `AFTERPSEUDOPLUNGE` are now called before the enforcement of the constraint handlers, in particular before the branching
8175 rules; in this way, the branching rule can already benefit from a tighter primal bound
8176 - if a heuristic found a better solution after the LP loop (and in particular the `AFTERNODE` heuristics in the root node
8177 of the very first run, see above), domain propagation and LP solving is triggered again; this allows for additional
8178 reduced cost tightening and other dual propagations
8179 - slightly modified `crossover` and `rins` heuristics
8180 - improved performance of intdiving heuristic
8181 - improved heuristic `octane` and `shifting`
8182 - slightly modified rens and localbranching heuristics
8183 - modified guided diving heuristic such that it equals the original version of the heuristic (i.e., round in direction of the
8184 current incumbent solution instead of the average of all primal feasible solutions)
8185 - ID character for intdiving heuristic is now `I`
8187- Separation and Cuts:
8188 - c-MIR cuts try now to scale the cut to integral values; however, cuts are still generated if this fails
8189 - hard-coded relative objective gain to consider a separation loop to be stalling is now changed from 1e-3 to 1e-4,
8190 which means that separation is not aborted as early as before
8191 - modified c-MIR cut separator to more closely resemble the original version of Marchand and Wolsey
8194 - possibility of SAT-like restarts after a number of conflict constraints have been found
8195 - improved presolving of and, or and xor constraints
8196 - implemented additional dual presolving in linear constraint handler
8197 - slightly modified presolving of varbound constraint handler
8202### New and changed callbacks
8204- new parameter `solinfeasible` for constraint handler callback methods `ENFOLP` and `ENFOPS`
8205- replaced callback parameter `inlploop` and `inplunging` by `heurtiming` in `SCIP_DECL_HEUREXEC`
8206- slightly changed the meaning of the result codes returned by external relaxators: if they modify the LP or tighten
8207 bounds of variables, they are not automatically be called again (it is assumed that they already made use of these
8208 changes). They are only called again, if they returned `SCIP_SUSPENDED` or if some other plugin modified the LP.
8210### Deleted and changed API methods
8212- new parameter `escapecommand` for SCIPdialoghdlrAddHistory()
8213- removed method SCIPgetVarData(); use SCIPvarGetData() from pub_var.h instead
8214- new calls SCIPgetLPBInvCol() and SCIPgetLPBInvACol() to access the basis inverse and simplex tableau columnwise
8215- new parameter `ndomredsfound` of SCIPpropagateProbing()
8216- new parameters `fixintegralrhs`, `maxfrac`, `mksetcoefs` and `fracnotinrange` in SCIPcalcMIR()
8217- modified SCIPfixVar() such that in problem creation stage it will change the bounds as requested even if the fixing
8218 value is outside of the current bounds
8219- replaced parameters `pseudonodes`, `duringplunging`, `duringlploop` and `afternode` by `timingmask` in
8220 SCIPincludeHeur() and constructor of ObjHeur() class use the following table to translate old settings into the new
8223| PSEUDONODES | DURINGPLUNGING | DURINGLPLOOP | AFTERNODE | timingmask |
8224|-------------|----------------|--------------|-----------|---------------------------------------------------------------|
8225| FALSE | FALSE | FALSE | FALSE | SCIP_HEURTIMING_BEFORENODE |
8226| TRUE | FALSE | FALSE | FALSE | SCIP_HEURTIMING_BEFORENODE |
8227| FALSE | TRUE | FALSE | FALSE | SCIP_HEURTIMING_BEFORENODE |
8228| TRUE | TRUE | FALSE | FALSE | SCIP_HEURTIMING_BEFORENODE |
8229| FALSE | FALSE | TRUE | FALSE | SCIP_HEURTIMING_BEFORENODE \| SCIP_HEURTIMING_DURINGLPLOOP |
8230| TRUE | FALSE | TRUE | FALSE | SCIP_HEURTIMING_BEFORENODE \| SCIP_HEURTIMING_DURINGLPLOOP |
8231| FALSE | TRUE | TRUE | FALSE | SCIP_HEURTIMING_BEFORENODE \| SCIP_HEURTIMING_DURINGLPLOOP |
8232| TRUE | TRUE | TRUE | FALSE | SCIP_HEURTIMING_BEFORENODE \| SCIP_HEURTIMING_DURINGLPLOOP |
8233| FALSE | FALSE | FALSE | TRUE | SCIP_HEURTIMING_AFTERLPPLUNGE |
8234| TRUE | FALSE | FALSE | TRUE | SCIP_HEURTIMING_AFTERPLUNGE |
8235| FALSE | TRUE | FALSE | TRUE | SCIP_HEURTIMING_AFTERLPNODE |
8236| TRUE | TRUE | FALSE | TRUE | SCIP_HEURTIMING_AFTERNODE |
8237| FALSE | FALSE | TRUE | TRUE | SCIP_HEURTIMING_AFTERLPPLUNGE \| SCIP_HEURTIMING_DURINGLPLOOP |
8238| TRUE | FALSE | TRUE | TRUE | SCIP_HEURTIMING_AFTERPLUNGE \| SCIP_HEURTIMING_DURINGLPLOOP |
8239| FALSE | TRUE | TRUE | TRUE | SCIP_HEURTIMING_AFTERLPNODE \| SCIP_HEURTIMING_DURINGLPLOOP |
8240| TRUE | TRUE | TRUE | TRUE | SCIP_HEURTIMING_AFTERNODE \| SCIP_HEURTIMING_DURINGLPLOOP |
8243 - renamed all occurences of `removeable` by the correct English word `removable`: SCIPconsIsRemovable(),
8244 SCIPsetConsRemovable(), SCIPvarIsRemovable(), SCIPcolIsRemovable(), SCIProwIsRemovable()
8245 - new parameter `sticktonode` in SCIPcreateCons(), SCIPcreateConsAnd(), SCIPcreateConsBounddisjunction(),
8246 SCIPcreateConsKnapsack(), SCIPcreateConsLinear(), SCIPcreateConsLogicor(), SCIPcreateConsOr(),
8247 SCIPcreateConsVarbound(), SCIPcreateConsXor(), SCIPcreateConsSetpart(), SCIPcreateConsSetpack(),
8248 SCIPcreateConsSetcover(): usually, you should set this to FALSE; if you want to add constraints as node markers with
8249 node data and, e.g., use the `activate` and `deactivate` callbacks to get informed about the activation and
8250 deactivation of the node, you should set this flag to TRUE in order to make sure, that the constraint will always be
8251 associated to the node and not moved to a more global node if this would be possible
8252 - slightly changed semantics of SCIPaddConsNode() and SCIPaddConsLocal(), such that a constraint which is added to the
8253 root node now enters the global problem (and is still existing after a restart)
8255### New API functions
8259- SCIPgetGlobalCutpool(), SCIPgetPoolCuts(), SCIPcutpoolGetCuts(), SCIPcutGetRow() and SCIPcutGetAge()
8260- SCIPconsGetNLocksPos() and SCIPconsGetNLocksNeg()
8262### Command line interface
8264- command shell now understands escape characters `\``,`'` and `\` which makes it possible to read in files with spaces in the
8267### Interfaces to external software
8269- updated XPress interface to XPress-MP 17 (contributed by Michael Perregaard)
8271### Changed parameters
8273- changed default value of `heuristics/octane/usediffray` to FALSE
8274- removed parameter `heuristics/octane/usediffbwray`
8275- renamed parameter `heuristics/octane/useavgray` to `heuristics/octane/useavgnbray`
8276- changed default value of `heuristics/rens/binarybounds` to TRUE
8277- changed default value of `heuristics/octane/freq` to -1 in order to deactivate Octane
8278- parameter `heuristics/feaspump/maxsols` is now strict, i.e., if n solutions were already found, the feasibility pump
8279 starts to work only if `maxsols <= n`, instead of `maxsols < n`
8283- `conflict/restartnum` and `conflict/restartfac`
8284- `heuristics/octane/useavgray`
8285- `heuristics/octane/useavgwgtray`
8286- `limits/absgap` to define an absolute gap limit
8287- `separating/cmir/aggrtol`
8288- `separating/cmir/densityscore`
8289- `separating/cmir/fixintegralrhs`
8290- `separating/maxruns`
8291- `presolving/restartminred` which forbids another restart if the last one was not successful enough
8292- `propagating/abortoncutoff`
8293- `reading/zplreader/changedir` to control behavior of path switching of ZIMPL file reader
8294- `reading/zplreader/parameters` to pass additional parameters to ZIMPL
8301- added ncurses to the readline entries in the `make/make.*` files
8302- added quotes to sed expressions in Makefile (needed under Windows)
8303- modified makefiles for Windows/Intel
8304- added automatic query script in the Makefile for soft-link names
8309- fixed bug with string pointer copy instead of string content duplication in constructors of C++ wrapper classes
8310- fixed bug in CPLEX interface with basis access methods that dualopt has to be called for more error status codes
8311- fixed bug with inserting two variable bounds of the same type on the same variable with the same bounding variable but
8312 with different sign of coefficient (e.g., `x <= 10*z + 5` and `x <= -5*z + 10`); in previous version, one of the two was
8313 removed, although both have a useful meaning; now, we keep both and detect a stronger global bound in the implication graph presolving
8314- objective function is now also checked for integrality after problem transformation (fixed a bug that a solution which
8315 was generated between transformation and presolving for an integral objective function did not reduce the cutoff bound by one)
8316- fixed a bug with cmir cut efficacy calculation (however, on my first tests, the performance reduced slightly!)
8317- fixed bug that SCIPvarGetAvgSol() always returned the upper bound (affected guided diving heuristic)
8318- fixed bug in RENS, RINS, Local Branching, Crossover and Mutation heuristics with wrong variable-subvariable assignments
8319- fixed bug in infeasible/bound-exceeding LP conflict analysis if the bounds were relaxed in diving (happens in intshifting heuristic)
8322 - fixed bug with adding constraints with `INITIAL=true` and separating them afterwards, which lead to a second addition of
8323 the constraint's relaxation in the child node
8324 - separation LPs are now immediately resolved after a bound change was generated by a cut separator; before, the
8325 separation round was prematurely aborted, which means that a separation round limit was sometimes reached very quickly
8326 and some of the separators were not even called a single time
8328- Cmir Cut Separator:
8329 - too large deltas are now also rejected in c-MIR cut separation
8330 - fixed bug in cmir cut separator, that 8*delta was not tried
8331 - fixed bug in cmir cut separator with wrong sign of slack in row score function
8332 - fixed bug in cmir cut separator with weights fixed to zero, thus making the current aggregation invalid
8333 - fixed bug in cmir cut separator with wrong calculation of cut efficacies
8335@page RN0_8 Release notes for SCIP 0.8
8337@section RN082 SCIP 0.8.2
8338*************************
8343- additional flag `delay` for pricers
8344- new propagator `rootredcost` which applies reduced cost fixing at the root node whenever a best new primal solution was found
8345- new separator `redcost` which replaces the internal reduced cost strengthening
8348 - extensions to the LP are kept even if the LP is not solved at the current node; however, if the LP turned out to be
8349 numerically instable, the extensions of the current node are still discarded
8350 - added removal of bound-redundant rows from the LP during root node LP solving loop
8351 - new display column `lpobj`
8354 - slightly changed priorities of constraint handlers
8355 - now, conflict constraints are also created if they were generated in strong branching or diving with insertion depth
8356 equal to the current depth
8357 - new constraint handler `bounddisjunction`
8360 - renamed `sol` file reader to `fix` file reader (reads partial solution files and fixes variables to the given values)
8361 - added `sol` file reader which reads complete solution files and adds the solutions to the solution pool
8362 - LP and MPS file readers are now able to parse lazy constraints and user cuts sections
8365 - knapsack presolver now generates cliques in the clique table (this essentially solves `neos1.mps`)
8366 - new presolver `inttobinary`
8369 - new primal heuristic `shifting`
8370 - diving heuristics abort earlier (did not come back in reasonable time on `fast0507`)
8375- new solution status code `SCIP_STATUS_STALLNODELIMIT`
8377### New and changed callbacks
8379- slightly modified semantics of the `CONSINITLP` callback in the constraint handlers
8381### Deleted and changed API methods
8383- methods SCIPisLbBetter() and SCIPisUbBetter() have an additional parameter and slightly different meaning (they now
8384 compare the bound improvement *relatively* to the width of the domain and the bound itself)
8385- SCIPgetNSols() now returns an int instead of `SCIP_Longint`
8386- method SCIPreadProb() does not call SCIPfreeTransform() anymore; file readers that want to extend the existing problem
8387 must now call SCIPfreeTransform() themselves before modifying the original problem
8388- method SCIPgetBinvarRepresentative() can now also be called in problem creation stage
8389- additional parameter `maxpricerounds` in method SCIPsolveProbingLPWithPricing()
8390- changed name of method SCIPpresolGetNVarTypes() to SCIPpresolGetNChgVarTypes()
8391- method SCIPsplitFilenames() now treats both versions of slashes, `/` and `\`, as directory delimiters (under MinGW and
8392 CygWin, both are valid; so, we cannot treat file names anymore where the other slash is used as a regular character)
8395 - marking a constraint to be `initial` now means in addition, that if the constraint is added to a local node it will
8396 enter the LP at the time the node is first processed, even if parameters forbid separation at this node
8397 - changed name of method SCIPconshdlrGetNVarTypes() to SCIPconshdlrGetNChgVarTypes()
8400 - method SCIPgetNConflictClausesFound() renamed to SCIPgetNConflictConssFound()
8401 - method SCIPgetNConflictClausesFoundNode() renamed to SCIPgetNConflictConssFoundNode()
8402 - method SCIPgetNConflictClausesApplied() renamed to SCIPgetNConflictConssApplied()
8404### New API functions
8406- SCIPsolveProbingLPWithPricing()
8407- SCIPchgVarLbRoot() and SCIPchgVarUbRoot()
8408- SCIPinRepropagation()
8409- SCIPaddDialogInputLine() and SCIPaddDialogHistoryLine()
8410- SCIPtransformProb() to create the transformed problem; enables the user, e.g., to add primal solutions before the presolving begins
8411- SCIPcreateSolCopy()
8415 - SCIPgetRowKnapsack(), SCIPgetRowLinear(), SCIPgetRowLogicor(), SCIPgetRowSetppc(), and
8416 SCIPgetRowVarbound() for obtaining the linear relaxation of a corresponding constraint
8417 - SCIPgetLhsVarbound(), SCIPgetRhsVarbound(), SCIPgetVarVarbound(), SCIPgetVbdvarVarbound(), and
8418 SCIPgetVbdcoefVarbound()
8419 - SCIPgetLPRootObjval(), SCIPgetLPRootColumnObjval() and SCIPgetLPRootLooseObjval()
8420 - SCIPcolGetMinPrimsol() and SCIPcolGetMaxPrimsol()
8421 - SCIPgetFocusDepth()
8424 - SCIPgetAvgPseudocostScore()
8425 - SCIPgetAvgPseudocostScoreCurrentRun()
8426 - SCIPgetAvgConflictScore()
8427 - SCIPgetAvgConflictScoreCurrentRun()
8428 - SCIPgetAvgInferenceScore()
8429 - SCIPgetAvgInferenceScoreCurrentRun()
8430 - SCIPgetAvgCutoffScore()
8431 - SCIPgetAvgCutoffScoreCurrentRun()
8434 - SCIPgetColRedcost()
8435 - SCIPvarGetRootRedcost()
8438 - SCIPgetNVarsAnd() and SCIPgetVarsAnd()
8439 - SCIPgetWeightsKnapsack(), SCIPgetNVarsKnapsack(), SCIPgetVarsKnapsack() and SCIPgetWeightsKnapsack()
8440 - SCIPgetNVarsLinear(), SCIPgetVarsLinear() and SCIPgetValsLinear()
8441 - SCIPgetNVarsOr() and SCIPgetVarsOr()
8442 - SCIPgetNVarsXor() and SCIPgetVarsXor()
8444### Command line interface
8446- command line syntax changed to support batch modus without piping stdin with `<` or `|` operators
8447- advanced command line syntax:
8448 - `-l <logfile> `: copy output into log file
8449 - `-q `: suppress screen messages
8450 - `-s <settings> `: load parameter settings (.set) file
8451 - `-f <problem> `: load and solve problem file
8452 - `-b <batchfile>`: load and execute dialog command batch file (can be used multiple times)
8453 - `-c <command> `: execute single line of dialog commands (can be used multiple times)
8455### Interfaces to external software
8457### Changed parameters
8459- removed parameter `propagating/redcostfreq`, because reduced cost strengthening is now an external separator plugin
8460- removed parameter `conflict/maxunfixed`
8461- parameter `conflict/maxclauses` renamed to `conflict/maxconss`
8462- parameter `conflict/interclauses` renamed to `conflict/interconss`
8463- parameter `conflict/reconvclauses` replaced by `conflict/reconvlevels`
8464- parameter `conflict/uselp` replaced by `conflict/useinflp` and `conflict/useboundlp`
8465- changed default value of `constraints/obsoleteage` to -1
8466- changed default value of `branching/relpscost/conflictweight` to 0.01
8467- changed default value of `branching/relpscost/inferenceweight` to 0.0001
8468- changed default value of `branching/relpscost/cutoffweight` to 0.0001
8469- in bfs node selector, parameter `minplungedepth` is now stronger than `maxplungedepth` if they conflict
8473- `constraints/linear/separateall`
8474- `conflict/lpiterations`
8475- `conflict/keepreprop`
8476- `branching/relpscost/conflictweight`, `branching/relpscost/inferenceweight`,
8477 `branching/relpscost/cutoffweight` and `branching/relpscost/pscostweight`
8478- `conflict/settlelocal`
8479- `conflict/depthscorefac`
8480- `limits/stallnodes`
8487- removed ncurses and pthread libraries from the Makefile; pthread is now only linked if CPLEX is used
8492- fixed numerical bug in SCIPrealToRational() [thanks to Anders Schack-Nielsen]
8493- fixed bug in crossover heuristic with negative timelimit
8494- removed bug in conflict analysis with wrong redundancy check
8495- fixed bug that unexpected end of stdin (Ctrl-D or piped-in file without `quit` command) gives a segmentation fault
8496- fixed bug with inconsistent data structures after a global bound was changed at a local subproblem and the local
8497 bounds are not contained anymore in the new global bounds
8498- fixed dependency generation in example Makefiles
8501 - fixed bug in knapsack presolving with redundancy check after applyFixings() [thanks to Anders Schack-Nielsen]
8502 - fixed bug in knapsack separator with empty initial covers
8503 - fixed bug in knapsack constraint disaggregation that may lead to acceptance of infeasible solutions
8504 - fixed bug in knapsack constraint handler where a modifiable constraint may be declared redundant
8507 - fixed bug with missing LP size updates after pricing or cut separation in probing [thanks to Marc Nuenkesser]
8508 - fixed bug in CPLEX interface with getting basis information after the LP was modified and restored
8509 - fixed bug with updating LP size in probing
8510 - fixed bug that SCIPgetLPSolstat() returns a valid status code even if the LP was not yet constructed for the current node
8513 - fixed bug with invalid lazy updates after a restart where the LP is not solved again (e.g., due to all variables being fixed)
8514 - fixed bugs resulting from inactive general integer variables being member of the variable bounds array of a variable
8515 - fixed bug in updatePseudocost() with wrong lpgain distribution on multiple branching variables [thanks to Anders Schack-Nielsen]
8516 - fixed bug in objconshdlr.h where member variable scip_maxprerounds_ was declared as an `SCIP_Bool` instead of an int
8517 - branching on nearly-integral variables is now avoided in relpscost branching, which lead to a numerical assertion
8520 - fixed bug with adding implications that fix the implication variable to the opposite value (due to the bug, it was
8521 returned that the whole problem is infeasible)
8522 - removed wrong assert in varRemoveImplicsVbs()
8525 - fixed bug in SCIPcliqueSearchVar() [thanks to Anders Schack-Nielsen]
8526 - fixed bug in SCIPcliqueAddVar() [thanks to Anders Schack-Nielsen]
8529 - fixed bug in MPS file reader with `OBJSENSE`
8530 - fixed bug in LP reader with potentially uninitialized pointers [thanks to Martin Mueller]
8533 - it is now possible to branch on constraints without the risk of going into an infinite loop, because constraints marked as `initial`
8534 will be put to the LP relaxation (of the child nodes) even if separation is prohibited by the parameter settings
8535 - fixed bug that locally valid varbound constraints produce VLB/VUB entries [thanks to Anders Schack-Nielsen]
8537@section RN081 SCIP 0.8.1
8538*************************
8543- improved performance of the priority queue in conflict analysis
8544- slightly modified restartdfs node selector
8547 - new presolver `implics` to find bound changes and aggregations out of the implication graph
8548 - modified probing order in probing presolver
8551 - changed handling of added constraints in separation calls
8552 - modified bookkeeping of locally added and disabled constraints such that the order of enabling and disabling constraints stays the same
8553 - logic or constraint handler now adds implications on clauses with 2 literals to the implication graph
8554 - and/or constraint handlers now add implications to the implication graph
8555 - xor constraint handler now uses stronger LP relaxation without auxiliary variable for xor constraint with 2 operands
8558 - added preliminary version of `intdiving` heuristic (disabled in default settings)
8559 - added crossover heuristic
8562 - LP file reader now accepts the keyword `Integer` for defining the start of the integer variables section
8563 - new file reader for (partial) solutions
8565Examples and applications
8566-------------------------
8568- added two small pricer examples (for C and C++)
8569- updated example code (s.t. it compiles again)
8574### New and changed callbacks
8576- callback method `CONSSEPA` of constraint handler was split into two methods `CONSSEPALP` and `CONSSEPASOL`
8577- callback method `SEPAEXEC` of separator was split into two methods `SEPAEXECLP` and `SEPAEXECSOL`
8579### Deleted and changed API methods
8581- replaced method SCIPsepaWasDelayed() by SCIPsepaWasLPDelayed() and SCIPsepaWasSolDelayed()
8582- additional parameter `sol` for methods SCIPaddCut(), SCIPgetCutEfficacy() and SCIPisCutEfficacious()
8583- additional parameter `sol` for method SCIPseparateKnapsackCover()
8584- primal solutions may now contain values marked to be unknown (value is `SCIP_UNKNOWN`); unknown values don't contribute
8585 to the objective value of the solution; an unknown solution value should be treated as an arbitrary value in the
8586 variable's bounds, e.g., in the calculation of the feasibility of a constraint, a value inside the variable's bounds
8587 should be selected that makes the constraint as feasible as possible
8588- new parameter `printzeros` for methods SCIPprintSol(), SCIPprintTransSol(), SCIPprintBestSol() and SCIPprintBestTransSol()
8591 - replaced method SCIPconshdlrWasSeparationDelayed() by two methods SCIPconshdlrWasLPSeparationDelayed() and
8592 SCIPconshdlrWasSolSeparationDelayed()
8593 - renamed method SCIPgetNGlobalConss() to SCIPgetNConss()
8595### New API functions
8598- SCIPgetVarConflictScore() and SCIPgetVarConflictScoreCurrentRun()
8600- SCIPcreateUnknownSol()
8601- SCIPgetNConflictClausesFoundNode()
8602- SCIPvarSetDelorigData(), SCIPvarSetTransData() and SCIPvarSetDeltransData()
8603- SCIPvarHasBinaryImplic()
8604- SCIPgetFixedVars() and SCIPgetNFixedVars()
8605- SCIPgetConss(), SCIPgetNOrigConss() and SCIPgetOrigConss()
8606- SCIPsepaGetNConssFound() and SCIPsepaGetNDomredsFound()
8607- SCIPconstructLP() to force constructing the LP of the current node
8608- SCIPisLPConstructed()
8610### Command line interface
8612- added `write statistics` command to default user dialogs
8614### Changed parameters
8616- modified meaning of parameter `presolving/probing/maxtotaluseless`
8617- heuristics with `freq = 0` and `freqofs > 0` are now called in depth level freqofs instead of being called in the root
8619- added some parameters in local branching and RINS heuristic
8620- new parameter values `p`rimal simplex and `d`ual simplex in `lp/initalgorithm` and `lp/resolvealgorithm`
8624- `branching/inference/conflictweight`
8631- included version number in binary file name
8632- tried to make the code Windows compatible
8637- also removed history_length, if `NO_REMOVE_HISTORY` is defined to support older versions of the readline library
8638- hopefully fixed bug with wrong path slash `/` under Windows
8639- fixed bug with aggregating fixed variables
8642 - fixed bug in transitive implication addition
8643 - fixed wrong assert with implications that imply a fixed variable
8644 - removed bug in implication addition
8647 - fixed bug in ZIMPL model reader with wrong chdir, if .zpl file is in current directory
8648 - fixed bug in LP file reader with signed values without space between sign and value (e.g. `+2x` instead of `+ 2x`)
8649 - fixed various bugs in LP file reader
8650 - fixed bug in LP file reader with explicit zero coefficients
8653 - fixed numerics in probing and linear constraint handler (rentacar was detected to be infeasible in presolving)
8654 - fixed numerics in check method of linear constraint handler
8655 - fixed bug with numerical error in LP resolve after probing or diving
8658 - fixed bug with calling heuristics in depths smaller than their frequency offset
8659 - fixed bugs in local branching and RINS heuristic
8664- if one uses column generation and restarts, a solution that contains variables that are only present in the
8665 transformed problem (i.e., variables that were generated by a pricer) is not pulled back into the original space
8666 correctly, since the priced variables have no original counterpart
8668@section RN080 SCIP 0.8.0
8669*************************
8674- adding variable bounds automatically adds the corresponding implication
8675- changed restart dfs nodeselector to sort leaves by node number instead of node depth to aviod jumping around in the
8676 search tree after a restart was applied and the current dive ended due to infeasibility
8677- new Message Handler plugin
8678- added file reader for LP format
8679- introduced subversion string
8680- replaced all abort() calls by SCIPABORT(); this is defined in def.h to be `assert(FALSE)`
8681- added possibility to disable certain features by using `make USRFLAGS=-DNO_REMOVE_HISTORY`, `make
8682 USRFLAGS=-DNO_SIGACTION`, `make USRFLAGS=-DNO_RAND_R`, or `make USRFLAGS=-DNO_STRTOK_R`
8683- improved preprocessing abort criteria
8687 - conflict clauses are now collected in a conflict store, redundant clauses are eliminated and only the best `conflict/maxclauses`
8688 clauses are added permanently to the problem; the remaining clauses are only added temporarily, if they can be used for repropagation
8689 - modified the influence of the depth level in conflict analysis
8690 - slightly changed LP resolving loop in conflict analysis
8691 - if CPLEX returns that the LP exceeds the bound and if no additional LP solves are allowed in conflict analysis, we
8692 have to perform one additional simplex iteration to get the dual solution that actually violates the objective limit
8695 - reactivated multiaggregation in cons_linear.c on binary variables again (possible due to bug fix below)
8696 - improved preprocessing of variable bounds constraints
8697 - linear constraint handler now catches events of variables after the problem was completely transformed in order to
8698 avoid the whole bunch of `LOCKSCHANGED` events that are generated at problem transformation stage
8699 - added redundancy detection for pairs of constraints in setppc constraint handler
8701- Presolving and Cliques:
8702 - changed linear constraint presolving s.t. redundant sides are not removed if constraint is an equality
8703 - new event type `SCIP_EVENTTYPE_PRESOLVEROUND`
8704 - modified probing presolver to not add implications that are already included in the implication graph and clique table
8705 - incorporated clique and implication information in knapsack constraint presolving
8706 - removed transitive clique generation, because this produces way too many cliques
8709 - diving heuristics now apply propagation at each step
8710 - removed `objfeaspump` heuristic, because the functionality can be achieved by using the `feaspump` heuristic
8711 - diving heuristics are now applying propagation after each bound change
8712 - new primal heuristic `octane`
8713 - slightly changed feaspump heuristic, s.t. after finding a new best solution the target integral solution is modified randomly
8715- Separation and Cuts:
8716 - improved debugging for infeasible cuts and propagations, given a primal feasible solution
8717 - improved knapsack cover separation
8718 - improved performance of c-MIR separator
8719 - cut pool is now also separated in root node (to find cuts again that were removed from the LP due to aging)
8724- new event type `SCIP_EVENTTYPE_VARDELETED`
8725- new event `SCIP_EVENTTYPE_IMPLADDED`
8726- new event types `SCIP_EVENTTYPE_GLBCHANGED` and `SCIP_EVENTTYPE_GUBCHANGED`
8728### New and changed callbacks
8730- new callback parameter `validnode` for the `CONFLICTEXEC` method of conflict handlers, which should be passed to
8733### Deleted and changed API methods
8735- additional parameter `validnode` for SCIPaddConsLocal() and SCIPaddConsNode()
8736- SCIPhashtableRemove() can now also be called, if the element does not exist in the table
8737- SCIPhashmapRemove() can now also be called, if the element does not exist in the map
8738- additional parameter `branchdir` for SCIPbranchVar()
8739- replaced method SCIPmessage() by SCIPverbMessage() with additional parameter `file`
8740- put block memory shell and tclique algorithm into separate subdirectories
8741- new parameter `duringlploop` of SCIPincludeHeur(): heuristics can now run during the price-and-cut loop at a node
8743### New API functions
8745- SCIPgetNConflictClausesApplied()
8746- SCIPgetNConflictClausesApplied()
8747- SCIPhashtableExists()
8748- SCIPhashmapExists()
8749- SCIPnodeGetNumber()
8750- SCIPsolveProbingLP() to solve the LP in a probing node (enables mixing of propagation and LP solving for diving heuristics)
8751- SCIProwGetDualfarkas()
8752- SCIPgetCurrentNode()
8753- SCIPinterruptSolve()
8754- SCIPpropagateProbingImplications()
8755- SCIPgetLPI() which makes all methods in scip/lpi.h available to the user
8756- SCIPgetRandomInt() and SCIPgetRandomReal()
8758- SCIPheurGetNBestSolsFound()
8762 - SCIPgetVarStrongbranchLPAge()
8763 - SCIPvarIsTransformedOrigvar()
8764 - SCIPvarIsDeleted()
8767 - SCIPerrorMessage()
8768 - SCIPwarningMessage()
8769 - SCIPdialogMessage()
8771 - SCIPsetMessagehdlr()
8772 - SCIPsetDefaultMessagehdlr()
8773 - SCIPgetMessagehdlr()
8774 - new file i/o methods SCIPfopen(), SCIPfclose(), SCIPfprintf(), ... that operate on the data type `SCIPFILE`; these
8775 methods automatically use zlib methods if the zlib is enabled
8778 - SCIPvarGetNCliques()
8779 - SCIPvarGetCliques()
8780 - SCIPvarsHaveCommonClique()
8781 - SCIPvarHasImplic()
8782 - SCIPcliqueGetNVars()
8783 - SCIPcliqueGetVars()
8784 - SCIPcliqueGetValues()
8787 - SCIPcalcCliquePartition()
8789- Constraint handler:
8790 - SCIPgetDualfarkasLinear() of linear constraint handler
8791 - SCIPgetDualfarkasLogicor() of logicor constraint handler
8792 - SCIPgetDualfarkasSetppc() of setppc constraint handler
8793 - SCIPgetDualsolKnapsack() of knapsack constraint handler
8794 - SCIPgetDualfarkasKnapsack() of knapsack constraint handler
8795 - SCIPgetDualsolVarbound() of varbound constraint handler
8796 - SCIPgetDualfarkasVarbound() of varbound constraint handler
8797 - SCIPconsGetValidDepth()
8798 - SCIPsetConsInitial()
8799 - SCIPsetConsSeparated()
8800 - SCIPsetConsEnforced()
8801 - SCIPsetConsChecked()
8802 - SCIPsetConsPropagated()
8803 - SCIPsetConsLocal()
8804 - SCIPsetConsDynamic()
8805 - SCIPsetConsRemoveable()
8807### Command line interface
8809- added command `write solution` to default dialog
8810- added commands `write problem` and `write transproblem` to default dialog
8812### Changed parameters
8814- additional setting `SCIP_VERBLEVEL_DIALOG` in `display/verblevel` parameter
8815- additional LP pricing setting `partial`
8816- replaced parameter `presolving/restartbdchgs` with parameters `presolving/maxrestarts` and `presolving/restartfac`
8817- replaced parameter `constraints/linear/maxpresolaggrrounds` with `constraints/linear/maxpresolpairrounds`
8818- parameters `constraints/agelimit` and `constraints/obsoleteage` now iterprete the value 0 as a dynamic setting
8819- number of fractional variables included in parameter `separating/maxstallrounds`
8821- Changed default values:
8822 - changed default values of `heuristics/∗/maxdiveavgquot` and `heuristics/∗/maxdiveavgquotnosol` to 0
8823 - changed default values of `constraints/agelimit` and `constraints/obsoleteage` to 0
8824 - changed default values of `heuristics/objpscostdiving/maxsols` and `heuristics/rootsoldiving/maxsols` to -1
8825 - changed default value of `separating/strongcg/maxroundsroot` to 20
8826 - changed default value of `separating/cmir/maxroundsroot` to 10
8827 - changed default value of `constraints/linear/maxaggrnormscale` to 0.0, which means to not apply aggregation
8828 - changed default value of `separating/maxstallrounds` to 5
8829 - changed default value of `presolving/probing/maxfixings` to 50
8830 - changed default parameter values to MIP settings:
8831 + `conflict/useprop` = FALSE
8832 + `conflict/usepseudo` = FALSE
8833 + `display/verblevel` = 4
8834 + `separating/poolfreq` = 0
8835 + `constraints/linear/sepafreq` = 0
8836 + `constraints/and/sepafreq` = 0
8837 + `constraints/conjunction/sepafreq` = 0
8838 + `constraints/knapsack/sepafreq` = 0
8839 + `constraints/knapsack/sepacardfreq` = 0
8840 + `constraints/logicor/sepafreq` = 0
8841 + `constraints/or/sepafreq` = 0
8842 + `constraints/setppc/sepafreq` = 0
8843 + `constraints/varbound/sepafreq` = 0
8844 + `constraints/xor/sepafreq` = 0
8845 + `separating/clique/freq` = 0
8846 + `separating/cmir/freq` = 0
8847 + `separating/gomory/freq` = 0
8848 + `separating/impliedbounds/freq` = 0
8849 + `separating/strongcg/freq` = 0
8853- `branching/fullstrong/reevalage`
8854- `conflict/maxclauses`
8855- `conflict/allowlocal`
8856- `constraints/knapsack/disaggregation`
8857- `presolving/probing/maxtotaluseless`
8858- `separating/cmir/maxfails`, `separating/cmir/maxfailsroot` and `separating/cmir/trynegscaling`
8862- MAJOR CHANGE: preceeded all data types with `SCIP_`: you may use shell script reptypes_scip.sh to rename the SCIP
8863 data types in your own source code (But use with care! Create a backup copy of your source first!)
8870- modified the Makefile to accept an additional parameter `VERBOSE={true,false}`
8871- added flags `READLINE=true/false`, `ZLIB=true/false`, `ZIMPL=true/false` to Makefile
8876- fixed minor bugs in debug code of primal.c and sol.c
8877- variables that are being multiaggregated are now automatically removed from all other variables' variable bound and
8878 implication arrays; this fixes bugs with methods, that rely on the fact, that the entries in the variable bound and
8879 implication arrays are active variables only
8880- aggregations are now always performed in a way, such that the variable of more general type is aggregated (with type
8881 generality being cont > implint > int > bin); in this way, a binary variable's representant is always binary (which
8882 was not the case before and resulted in a bug in SCIPgetBinvarRepresentative())
8883- removed bug in presol_probing.c: the vars of the sorted variables array have to be captured
8884- fixed bug in the output of solutions with priced variables
8885- fixed bug in propagation with parameters prop_maxrounds and prop_maxroundsroot
8886- conflict analysis can now handle errors in LP solving calls
8887- removed bug in SCIPvarAddVlb() and SCIPvarAddVub() with fractional vlb/vubcoefs
8888- fixed bug that primal or dual rays might not be available because the wrong solver was used
8889- included message.o in LPI library, s.t. one can link this library indepentent of SCIP
8890- fixed bug that if diving heuristic that changes the objective values finds a solution, the cutoff is reinstalled in
8891 the LP solver (although the objective value has no meaning due to the objective function modification)
8894 - LP primal feasibility for bounds is now defined as absolute measure (was relative to the bound before); this fixes a bug (see alu8_9.mps),
8895 that an LP with an integral variable fixed to a large value yields an accepted solution with that variable slightly different than the fixed
8896 value; the integrality feasibility condition is measured with absolute differences, which leads to the fixed integer variable being fractional;
8897 this leads to an error if branching is performed on this variable
8898 - fixed bug with redundant self implications that wrongly lead to the detection of infeasibility
8899 - fixed bug with potential infinite loop if a separator is delayed and the LP is infeasible
8902 - removed wrong asserts from lpi_cpx.c
8903 - removed wrong assertion in varAddImplic()
8906 - locally fixed variables are no longer used as branching candidates even if their LP solution value is fractional (due
8907 to numerical reasons, see above)
8908 - fixed numerical bug in pseudo objective propagator with only slightly tightened bounds
8909 - removed bug that an LP might be declared to be solved even if it was marked erroneous due to numerical problems
8911- Constraint Handlers:
8912 - fixed bug in linear constraint handler with variables fixed to infinity
8913 - fixed bug with constraint handlers that can only enforce their constraints by adding cuts, but the maximal number of
8914 cuts to separate is set to 0; now, cuts that are generated in the constraint enforcement are used in any case
8915 - fixed bug in knapsack constraint presolving with tightening coefficients and capacity
8916 - fixed bug with modifiable constraints in linear constraint handler preprocessing
8917 - fixed bug in linear constraint handler that global activities are not updated after global bound changes
8919- Separation and Cuts:
8920 - global bound changes now lead to the removal of redundant implications (such that the asserts in sepa_implbounds.c are now correct)
8921 - due to usage of variable bounds, SCIPcalcMIR() may return LOOSE variables in the cut -> modified sepa_cmir.c, sepa_gomory.c and
8922 sepa_strongcg.c to use SCIPcreateEmptyRow() and SCIPaddVarsToRow() instead of SCIPcreateRow() which only works for COLs
8923 - fixed bug in clique separator that reduced performance
8924 - increased performance of clique separator by allowing only a certain number of zero-weighted fill ins
8926@page RN0_7 Release notes for SCIP 0.7
8928@section RN079 SCIP 0.7.9
8929*************************
8934- aging and cleanup now only remove non-basic columns and basic rows, s.t. resolving can be applied with 0 simplex iterations
8935- it is now possible to create subnodes in probing and use backtracking to undo probing changes
8936- bounds of variables are included in the feasibility checks for solutions
8937- support for barrier algorithm
8938- changed implementation of automatic minplungedepth and maxplungedepth calculation in bfs node selector
8941 - new plugin: probing presolver
8942 - probing is now also possible in presolving stage
8943 - it is now possible to interrupt and continue presolving
8945- Separation and Cuts:
8946 - new plugin: clique separator for clique cuts with at least 3 elements
8947 - new plugin: implied bound cuts separator
8948 - included debugging module to check whether cutting planes cut off the optimal solution
8951 - changed implementation of reliability value calculation in reliability branching; slightly modified influence of
8952 maximal total number of strong branching LP iterations in reliability branching
8953 - changed implementation of maximal strong branching iterations calculation in reliability branching
8956 - if verblevel is at least `NORMAL`, an automatical check of the best solution is performed in the original problem, and
8957 an error message is displayed, if it violates an original constraint
8958 - due to the new constraint handler `cons_cumulative.{c,h}` SCIP can resource-constraint scheduling problem
8959 - during probing, propagation of bounds is now always performed in linear constraint handler, ignoring the parameter `tightenboundsfreq`
8960 - new implementation of the clique graph construction method in clique separator
8961 - new constraint handler `cons_cumulative.{c,h}`
8964 - new implementation of the feasibility pump heuristic by Timo Berthold (replaces old implementation); old
8965 implementation is now called `objfeaspump`; parameter names have been changed accordingly
8966 - diving heuristics now compare their number of LP iterations with the number of node LP iterations instead of the total
8967 number (including their own) LP iterations
8968 - modified the automatic objfactor setting of feaspump heuristic to let the objective function have stronger influence
8970Examples and applications
8971-------------------------
8973- added TSP example in `examples/TSP`
8978### New and changed callbacks
8980- new callback methods `INITSOL` and `EXITSOL` for variable pricers, primal heuristics, conflict handlers, relaxators,
8981 separators, propagators, event handlers, node selectors and display columns
8982- callback method `CONFLICTEXEC` of conflict handlers receive additional parameters `dynamic` and `removeable`
8983- constraint handler callback methods `CONSLOCK` and `CONSUNLOCK` are replaced by a single method `CONSLOCK` with the number
8984 of locks being positive or negative
8986### Deleted and changed API methods
8988- calling SCIPaddCut() with `forcecut=TRUE` will add the cut to the LP even if it is redundant
8989- SCIPreadProb() does not free the current problem, this is done in SCIPcreateProb() now, which is usually
8990 called by a problem reader; in this way, a reader can generate `extra information` for the current problem, s.t. the
8991 full problem information can be distributed to different files read by different readers
8992- SCIPgetVarStrongbranch() and SCIPgetVarStrongbranchLast() now have two additional parameters that can be used
8993 to check, whether the returned values are correct dual bounds
8994- SCIPgetBinvarRepresentative() now returns the fixed or multi-aggregated variable instead of returning `NULL` or
8995 aborting with an error message
8996- SCIPdispDecimal() is replaced by SCIPdispInt() and SCIPdispLongint()
8997- additional parameter `maxproprounds` in SCIPpropagateProbing()
8998- changed memory interface (see memory.h), `MEMHDR` is now called `BLKMEM`
8999- source code was moved into subdirectories: replace includes `scip.h` by `scip/scip.h` and
9000 `objscip.h` by `objscip/objscip.h`; This should allow a user to have include files of the same name as the ones
9001 of SCIP, e.g. `tree.h` or `var.h`.
9002- event handlers are now available as C++ wrapper class
9003- new flag `afterrelaxation` for primal heuristics
9006 - removed method SCIPsolGetObj(), use SCIPgetSolOrigObj() or SCIPgetSolTransObj() instead
9007 - additional parameter `checkbounds` for SCIPtrySol(), SCIPtrySolFree(), SCIPcheckSol()
9010 - SCIPvarLock(), SCIPvarLockDown(), SCIPvarLockUp(), SCIPvarLockBoth(), SCIPvarUnlock(), SCIPvarUnlockDown(),
9011 SCIPvarUnlockUp() and SCIPvarUnlockBoth() are replaced by SCIPaddVarLocks() which returns a `RETCODE`
9012 - SCIPvarGetLbGlobal(), SCIPvarGetUbGlobal(), SCIPvarGetLbLocal() and SCIPvarGetUbLocal() now return the
9013 corresponding values of the transformed problem or current subproblem even for original problem variables
9014 - SCIPvarGetProbvar(), SCIPvarGetProbvarBinary() now return the fixed or multi-aggregated variable instead of
9015 returning `NULL` or aborting with an error message; in SCIPvarGetProbvarBinary(), the fixing of a fixed variable does
9016 not influence the negation status anymore
9017 - SCIPvarGetProbvarBound() returns the multi-aggregated variable instead of aborting with an error message
9018 - SCIPvarGetProbvarSum() does not set *var to `NULL` for fixed variables anymore; it may also return a
9019 multi-aggregated variable instead of aborting with an error message
9020 - SCIPaddVarImplication() now also adds variable lower and upper bounds, if the implied variable is non-binary
9021 - additional parameter `aggregated` in SCIPmultiaggregateVars()
9024 - SCIPvarLockDownCons(), SCIPvarLockUpCons(), SCIPvarUnlockDownCons() and SCIPvarUnlockUpCons() are replaced by
9025 SCIPlockVarCons() and SCIPunlockVarCons() which return a `RETCODE`
9026 - SCIPlockConsVars() and SCIPunlockConsVars() replaced with method SCIPaddConsLocks()
9027 - SCIPconshdlrGetNConss() is replaced by SCIPconshdlrGetNActiveConss() (returning the number of active
9028 constraints); method SCIPconshdlrGetNConss() does now return the total number of existing constraints, active and inactive
9029 - SCIPconshdlrGetStartNConss() is now called SCIPconshdlrGetStartNActiveConss()
9030 - SCIPconshdlrGetMaxNConss() is now called SCIPconshdlrGetMaxNActiveConss()
9031 - SCIPdisableConsNode() is replaced by SCIPdelConsNode()
9032 - SCIPdisableConsLocal() is replaced by SCIPdelConsLocal()
9033 - added new parameter `dynamic` to SCIPcreateCons() and all plugin methods SCIPcreateCons...()
9035### New API functions
9038- SCIPcreateOrigSol()
9039- SCIPwriteImplicationConflictGraph()
9042- SCIPgetVarNStrongbranchs()
9043- SCIPcolGetNStrongbranchs()
9044- SCIPfindSimpleRational()
9045- SCIPselectSimpleValue()
9048 - SCIPvarGetLbOriginal()
9049 - SCIPvarGetUbOriginal()
9050 - SCIPvarGetImplIds()
9051 - SCIPvarGetOrigvarSum()
9056 - SCIPenableConsSeparation()
9057 - SCIPdisableConsSeparation()
9058 - SCIPconsIsSeparationEnabled()
9061 - SCIPgetAvgPseudocost()
9062 - SCIPgetAvgPseudocostCurrentRun()
9063 - SCIPgetAvgPseudocostCount()
9064 - SCIPgetAvgPseudocostCountCurrentRun()
9065 - SCIPgetAvgInferences()
9066 - SCIPgetAvgInferencesCurrentRun()
9067 - SCIPgetAvgCutoffs()
9068 - SCIPgetAvgCutoffsCurrentRun()
9071 - SCIPisLPSolBasic() to check, whether the current LP solution is basic (i.e. due to a simplex algorithm or barrier with crossover)
9072 - SCIPgetNPrimalLPs()
9073 - SCIPgetNPrimalLPIterations()
9075 - SCIPgetNDualLPIterations()
9076 - SCIPgetNBarrierLPs()
9077 - SCIPgetNBarrierLPIterations()
9078 - SCIPgetNPrimalResolveLPs()
9079 - SCIPgetNPrimalResolveLPIterations()
9080 - SCIPgetNDualResolveLPs()
9081 - SCIPgetNDualResolveLPIterations()
9084 - SCIPsepaIsDelayed()
9085 - SCIPsepaWasDelayed()
9086 - SCIPpropIsDelayed()
9087 - SCIPpropWasDelayed()
9088 - SCIPpresolIsDelayed()
9089 - SCIPpresolWasDelayed()
9090 - SCIPconshdlrIsSeparationDelayed()
9091 - SCIPconshdlrIsPropagationDelayed()
9092 - SCIPconshdlrIsPresolvingDelayed()
9093 - SCIPconshdlrWasSeparationDelayed()
9094 - SCIPconshdlrWasPropagationDelayed()
9095 - SCIPconshdlrWasPresolvingDelayed()
9097### Command line interface
9099- command line history in interactive shell now only stores useful commands
9101### Interfaces to external software
9103- removed storing of dual norms in LPI state of CPLEX interface (too memory consuming)
9105### Changed parameters
9107- default frequency offset of fracdiving heuristic changed to 3
9108- default frequency offset of (new) feaspump heuristic changed to 0
9109- default frequency offset of objfeaspump heuristic changed to 8
9110- changed default priority of primal heuristics
9111- renamed parameter `limits/sol` to `limits/solutions`
9112- changed default check priority of knapsack constraint handler to -600000
9113- changed default priority of Gomory cut separator to -1000 (will now be called after constraint handlers!)
9114- changed default priority of strong CG cut separator to -2000
9115- changed default priority of cmir cut separator to -3000
9116- changed default of parameter `lp/pricing` to `s`teepest edge pricing
9117- default parameter `branching/relpscost/minreliable` changed to 1.0
9118- default parameter `branching/relpscost/maxlookahead` changed to 8
9119- default parameter `branching/relpscost/sbiterofs` changed to 100000
9120- default parameter `heuristics/coefdiving/maxlpiterquot` changed to 0.05
9121- default parameter `heuristics/fracdiving/maxlpiterquot` changed to 0.05
9122- default parameter `heuristics/guideddiving/maxlpiterquot` changed to 0.05
9123- default parameter `heuristics/linesearchdiving/maxlpiterquot` changed to 0.05
9124- default parameter `heuristics/pscostdiving/maxlpiterquot` changed to 0.05
9125- default parameter `heuristics/feaspump/freq` changed to 20
9126- default parameter `heuristics/objfeaspump/freq` changed to 20
9127- default parameter `heuristics/objpscostdiving/freq` changed to 20
9128- default parameter `heuristics/rootsoldiving/freq` changed to 20
9129- default parameter `separating/clique/maxtreenodes` changed to -1
9133- new parameter delay for presolvers
9134- new parameter delaypresol for constraint handlers
9135- `branching/scorefunc`
9136- `constraints/.../delaypresol`
9137- `constraints/.../delayprop`
9138- `constraints/.../delaysepa`
9140- `conflict/removeable`
9141- `heuristics/coefdiving/maxlpiterofs`
9142- `heuristics/feaspump/maxlpiterofs`
9143- `heuristics/feaspump/maxsols`
9144- `heuristics/fracdiving/maxlpiterofs`
9145- `heuristics/guideddiving/maxlpiterofs`
9146- `heuristics/linesearchdiving/maxlpiterofs`
9147- `heuristics/objfeaspump/maxlpiterofs`
9148- `heuristics/objfeaspump/maxsols`
9149- `heuristics/objpscostdiving/maxlpiterofs`
9150- `heuristics/objpscostdiving/maxsols`
9151- `heuristics/pscostdiving/maxlpiterofs`
9152- `heuristics/rootsoldiving/maxlpiterofs`
9153- `heuristics/rootsoldiving/maxsols`
9154- `heuristics/fixandinfer/proprounds` and `heuristics/fixandinfer/minfixings`
9155- `lp/cleanupcolsroot` and `lp/cleanuprowsroot` to distinguish cleanup settings between root node and other nodes
9156- `lp/checkstability` to disable stability check of LP solver's result code
9157- `lp/initalgorithm` and `lp/resolvealgorithm` for switching between simplex and barrier algorithm
9158- `lp/pricing` to set the pricing strategy used in the LP solver
9159- `numerics/barrierconvtol` to set the convergence tolerance in the barrier algorithm
9160- `presolving/.../delay`
9161- `propagating/.../delay`
9162- `reading/cnfreader/dynamicconss`
9163- `reading/mpsreader/dynamicconss`
9164- `separating/.../delay`
9168- new possible result `SCIP_DELAYED` for `EXEC` method of separators, presolvers and propagators and `SEPA`, `PROP` and
9169 `PRESOL` methods of constraint handlers
9174- fixed bug in MPS file reader
9175- removed bug with applying reduced cost strengthening before pricing in all necessary variables
9176- negated variables must also be reset in SCIPvarInitSolve()
9177- fixed documentation of `CONSLOCK`-method (missing parameter `scip` in SCIPaddVarLocks())
9178- included missing `objrelax.h` in includes of objscip.h
9179- fixed bug that after a resolve and further preprocessing, existing primal solutions may get corrupted due to
9180 aggregations or fixings that are possible due to the primal bound (given by the best solution)
9181- fixed bug with primal bound becoming wrong, if in a prior run the optimal solution was found and the cutoff bound was
9182 thereby reduced due to further domain propagation w.r.t. the objective function
9183- fixed bug in SCIPisObjIntegral()
9184- fixed bug in SCIPprintError() with `file == NULL`
9185- heuristic's display character is now only shown the first time, the new solution was found
9186- fixed bug that SCIPreadProb() doesn't discard the transformed problem
9187- fixed bug with wrong euclidean norm calculation of row, if multiple coefficients for the same variable are added and
9188 the sorting of the row was delayed with SCIProwDelaySort()
9189- fixed bug with adding implications: wrong insertion position, if only the lower bound change was present but not the
9191- fixed bug in SCIPvarAddImplics() with wrong variable used in varAdjustBd()
9192- fixed bug in method reduced() of tclique_branch.c with sorting nodes in V
9195 - removed bug with objective norm calculation and column variables not in the LP (pricing)
9196 - LP error on forced LP resolve (due to 0 unfixed integers) now leads to an error (instead of accepting the pseudo
9197 solution as feasible)
9198 - fixed bug in CPLEX LP interface with dual norms
9201 - fixed bug that presolving time is not counted to solving time, if presolving is called explicitly with SCIPpresolve()
9202 - fixed bug where presolving fixings are counted even if the variable was already fixed
9203 - removed bug with dual presolver, that declared a problem to be unbounded or infeasible, if it could fix a variable to
9204 infinity even if its objective value is zero
9205 - fixed bug in knapsack constraint handler that fixed variables are sometimes not removed in presolving
9208 - fixed bug with unresolved numerical troubles in LP that don't render the LP useless at the current node
9209 - fixed numerical bugs in rounding heuristic and rootsoldiving heuristic
9212 - fixed bugs in separation store with single coefficient cuts that are converted into bound changes
9213 - at least one cut per separation round is added to the LP to avoid cycling, even if the cut is redundant
9214 - fixed bug in SCIProwCalcIntegralScalar() with rows consisting of only continuous variables (appeared in gomory cut
9215 separator on miplib/dcmulti.mps)
9216 - fixed bug in linear constraint handler's knapsack relaxation separator
9217 - fixed bugs in intobj separator
9218 - fixed bug in cmir separator with empty rows
9219 - fixed bug in implied bound cut separator: only implications between binary variables were generated before
9221- Constraint Handlers:
9222 - removed bug in knapsack constraint handler with merging multiple items if more than two items of the same variable
9223 appear in the constraint
9224 - removed bug in knapsack constraint handler with merging negated variables of equal weight at the end of the variables' array
9225 - fixed bug in linear constraint handler with eventdatas, if the original constraint has no variables
9226 - fixed bug that `CONSLOCK` method of constraint handlers that don't need constraints is not called
9227 - fixeg bug in setppc constraint handler with pairs of aggregated variables in the same constraint
9228 - fixed bug with globally deleting constraints, that have attached rows which are therefore not released in exitsol methods
9231 - removed conflict analysis of infeasible diving LP if pricing is activated
9232 - made conflict analysis available in presolving stage (for probing conflicts)
9234@section RN078 SCIP 0.7.8
9235*************************
9240- changed SCIProwCalcIntegralScalar() to a slightly different algorithm
9241- improved knapsack relaxation in linear constraint handler separator to scale the constraint in order to get integral
9242 coefficients instead of just rounding down all coefficients
9243- improved presolving of linear constraint handler: aggregation of two constraints with equal coefficient vector into
9245- improved presolving of knapsack constraint handler: aggregation of equal or negated variables in same constraint
9248 + priority of separators, propagators and presolvers decide whether the plugin is called before the corresponding
9249 constraint handler methods or after: plugins with nonnegative priorities are called before, plugins with negative
9250 priorities are called after the constraint handlers
9251 + new plugin class for relaxators (external relaxations, that can be used in parallel with LP relaxations)
9252 + if more than one result code applies to a plugin's execution, it should return the one that is higher in the call's
9258- even in optimized mode, the simple functions that are implemented as defines in the include files exist in the
9259 library, s.t. one can include the include files without `NDEBUG` and use the optimized library
9261### New and changed callbacks
9263- new branching rule plugin methods `INITSOL` and `EXITSOL`
9265### Deleted and changed API methods
9267- removed SCIPisFeasible(); use !SCIPisFeasNegative() instead
9268- SCIPisIntegral(), SCIPisFracIntegral(), SCIPfloor(), SCIPceil() and SCIPfrac() don't use the feasibility
9269 tolerance anymore (default: 1e-06); instead, they are using epsilon (default: 1e-09); instead, for handling
9270 integrality of a variable `in feasibility tolerances`, new methods SCIPisFeasIntegral(), SCIPisFeasFracIntegral(),
9271 SCIPfeasFloor(), SCIPfeasCeil() and SCIPfeasFrac() should be used
9272- in LPI, the semantics of SCIPlpiHasPrimalRay() and SCIPlpiHasDualRay() changed: methods return TRUE, if a ray exists
9273 and the solver can return it; new methods SCIPlpiExistsPrimalRay() and SCIPlpiExistsDualRay() check whether a ray
9274 exists without checking, if the solver knows and can return the ray
9276### New API functions
9279- SCIPgetLPColumnObjval() and SCIPgetLPLooseObjval()
9280- SCIPcalcIntegralScalar() with arbitrary array of Real values
9281- SCIPaddCoefKnapsack() in knapsack constraint handler
9282- SCIPisScalingIntegral() to check, whether the scaling of a value would lead to an integral value, measured
9283 against epsilon which is also scaled by the same scalar
9284- SCIPgetRealarrayMinIdx(), SCIPgetRealarrayMaxIdx(), SCIPgetIntarrayMinIdx(), SCIPgetIntarrayMaxIdx(),
9285 SCIPgetBoolarrayMinIdx(), SCIPgetBoolarrayMaxIdx(), SCIPgetPtrarrayMinIdx() and SCIPgetPtrarrayMaxIdx()
9286- SCIPbsortPtrInt() and SCIPbsortPtrIntInt()
9287- SCIPvarWasFixedAtIndex()
9288- SCIPaddConflictBd()
9289- SCIPprintMemoryDiagnostic()
9290- SCIPfindObj...() and SCIPgetObj...() in C++ wrapper interface to get the corresponding plugin object
9292### Changed parameters
9294- slightly changed the meaning of parameter `presolving/abortfac` a value of 0 now means to abort presolving only after
9295 no more change has been found
9300- assigning a value to a fixed variable in a solution with SCIPsetSolVal() does not return an error anymore, if the
9301 value is equal to the fixed value of the variable
9302- removed bug in SCIPisScalingIntegral()
9303- removed bugs with calling SCIPtightenVarLb(), SCIPtightenVarUb(), SCIPinferVarLbCons(), SCIPinferVarUbCons(),
9304 SCIPinferVarLbProp() and SCIPinferVarUbProp() in `PROBLEM` stage
9307 - solving loop is now immediately aborted, if a node on the active path is marked to be cut off
9308 - removed bug in resolving an interrupted problem, after the last solved node was cut off
9309 - removed bug with infinite solving loop if LP solving is turned off
9310 - removed bug with aborted solving in root node (e.g. due to time limit) that is tagged to be restarted
9313 - fixed bug in all-fullstrong branching with getting strong branching information for columns not in current LP
9314 - implemented missing case in solve.c with branching rules that add constraints
9317 - changed numerics for integrality check of coefficients (fixed bug with accumulated errors in rows s.t. the row's
9318 activity is no longer integral although the row is marked being integer)
9319 - slightly changed numerics in linear constraint handler presolving to fix a bug with coefficients detected to be scaled
9320 to an integral value, that are not integral after scaling due to a large scalar that increased the integrality gap to
9321 a value larger than epsilon
9323- Constraint handlers:
9324 - fixed bugs in consdataSwitchWatchedVars() of `or` and `and` constraint handlers
9325 - fixed wrong assertion in xor constraint handler with switching both watched variables to unwatched
9326 - fixed bugs in constraint handlers (and, logicor, or, setppc, xor) with calling conflict analysis during presolving
9327 - removed bug in knapsack constraint handler that appears if a variable is fixed to zero in knapsack presolving, which
9328 triggers a variable of the same knapsack to be fixed to one due to aggregation
9331 - removed bug in knapsack presolver
9332 - fixed bug in presolving with wrong number of newly fixed/aggregated/... variables/bounds/... after a restart
9334@section RN077 SCIP 0.7.7
9335*************************
9340- infeasible LPs in diving now produce conflict clauses (if LP conflict analysis is enabled)
9341- conflict analysis was slightly modified
9342- slightly changed aging strategy of logic or constraint handler
9347### Deleted and changed API methods
9349- method SCIPgetGap() and SCIPgetTransGap() now return infinity, if primal and dual bound have opposite sign (this
9350 removes the oddness with the gap increasing while the dual bound approaches zero)
9352### New API functions
9354- added methods SCIPgetVarsLogicor() and SCIPgetNVarsLogicor() in logic or constraint handler
9356### Changed parameters
9358- `lp/colagelimit` and `lp/rowagelimit` may now be set to -1 to disable deletion of columns/rows due to aging
9365- the file names in the archive file are now preceeded with a directory `scip-<version>/`
9366- the compiler is now also represented in the LP solver library names (e.g. you have to rename the softlink
9367 `libcplex.linux.x86.a` to `libcplex.linux.x86.gnu.a`)
9372- removed bug in conflict analysis that appears if the conflict is only active at the current depth level
9373- missing SCIPlpiIsPrimalFeasible() and SCIPlpiIsDualFeasible() implemented in lpi_spx.cpp and lpi_spx121.cpp
9374- removed preprocessing of linear constraint pairs with modifiable constraints
9377 - removed wrong assert `assert(eventfilter->len == 0 || eventfilter->eventmask != 0x00000000)` from event.c
9378 - removed wrong assert in conflict analysis (appeared on analyzing diving LP conflicts with both bounds of a non-binary variable changed)
9380@section RN076 SCIP 0.7.6
9381*************************
9386- creation of reconvergence clauses in conflict analysis
9387- first node of each plunging is not treated as plunging node w.r.t. calling primal heuristics
9388- improved performance of logic or constraint handler due to better watched variables handling
9393### Deleted and changed API methods
9395- changed SCIPcatchVarEvent() and SCIPdropVarEvent()
9396- SCIPstage() is now called SCIPgetStage()
9397- SCIPprintStatus() is now called SCIPprintStage()
9399### New API functions
9401- SCIPgetActivityLinear() in linear constraint handler
9402- SCIPgetFeasibilityLinear() in linear constraint handler
9403- SCIPchgVarBranchDirection()
9404- SCIPvarGetBranchDirection()
9405- SCIPgetStatus() returns the solution status
9406- SCIPprintStatus() outputs the solution status (beware, that the old SCIPprintStatus() method is now called SCIPprintStage())
9408### Changed parameters
9410- changed default frequency offset of pscostdiving `heuristics/pscostdiving/freqofs` to 2 and frequency offset of fracdiving
9411 `heuristics/feaspump/freqofs` to 0 in order to not call pscostdiving in root node, where nearly all pseudo costs are uninitialized.
9415- new parameter `separating/efficacynorm` to choose between Euclidean, maximum, sum and discrete norm in efficacy
9420- new possible result code `SCIP_DELAYED` for primal heuristics
9425- removed bugs in CLP Solver interface
9426- SCIP returned `gap limit reached` even if the problem was solved to optimality, if the optimal solution was found at a
9427 node with lower bound equal to the global lower bound
9428- after conversion of the focus node into a junction (e.g. in case of numerical troubles while solving the node's LP), the child
9429 nodes got the wrong LP fork attached (the common LP fork of the old and new focus node instead of the old focus node's LP fork)
9432 - bug reconvergence clauses in conflict analysis if bounds on non-binary variables were the reason for the fixing of the
9433 uip to create a reconvergence clause for
9434 - wrong sub calls in SCIPvarGet...CurrentRun() for aggregated variables
9435 - variables' conflict set counter was not reset when the problem was resolved again
9440- unbounded models lead to an error
9441- air04 and air05 return wrong optimal value (1 too large): possibly due to strong branching or setppc propagation?
9443@section RN075 SCIP 0.7.5
9444*************************
9449- started change log*/