Actual source code: snes.c
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_SetUp, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes `SNESSolve()` to generate an error immediately if the solver has not converged.
18: Logically Collective
20: Input Parameters:
21: + snes - iterative context obtained from `SNESCreate()`
22: - flg - `PETSC_TRUE` indicates you want the error generated
24: Options Database Key:
25: . -snes_error_if_not_converged <true,false> - cause an immediate error condition and stop the program if the solver does not converge
27: Level: intermediate
29: Note:
30: Normally PETSc continues if a solver fails to converge, you can call `SNESGetConvergedReason()` after a `SNESSolve()`
31: to determine if it has converged. Otherwise the solution may be inaccurate or wrong
33: .seealso: [](ch_snes), `SNES`, `SNESGetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes, PetscBool flg)
36: {
37: PetscFunctionBegin;
40: snes->errorifnotconverged = flg;
41: PetscFunctionReturn(PETSC_SUCCESS);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Indicates if `SNESSolve()` will generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from `SNESCreate()`
52: Output Parameter:
53: . flag - `PETSC_TRUE` if it will generate an error, else `PETSC_FALSE`
55: Level: intermediate
57: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes, PetscBool *flag)
60: {
61: PetscFunctionBegin;
63: PetscAssertPointer(flag, 2);
64: *flag = snes->errorifnotconverged;
65: PetscFunctionReturn(PETSC_SUCCESS);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - tells the `SNES` to always compute the residual (nonlinear function value) at the final solution
71: Logically Collective
73: Input Parameters:
74: + snes - the shell `SNES`
75: - flg - `PETSC_TRUE` to always compute the residual
77: Level: advanced
79: Note:
80: Some solvers (such as smoothers in a `SNESFAS`) do not need the residual computed at the final solution so skip computing it
81: to save time.
83: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetAlwaysComputesFinalResidual()`
84: @*/
85: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
86: {
87: PetscFunctionBegin;
89: snes->alwayscomputesfinalresidual = flg;
90: PetscFunctionReturn(PETSC_SUCCESS);
91: }
93: /*@
94: SNESGetAlwaysComputesFinalResidual - checks if the `SNES` always computes the residual at the final solution
96: Logically Collective
98: Input Parameter:
99: . snes - the `SNES` context
101: Output Parameter:
102: . flg - `PETSC_TRUE` if the residual is computed
104: Level: advanced
106: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetAlwaysComputesFinalResidual()`
107: @*/
108: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
109: {
110: PetscFunctionBegin;
112: *flg = snes->alwayscomputesfinalresidual;
113: PetscFunctionReturn(PETSC_SUCCESS);
114: }
116: /*@
117: SNESSetFunctionDomainError - tells `SNES` that the input vector, a proposed new solution, to your function you provided to `SNESSetFunction()` is not
118: in the functions domain. For example, a step with negative pressure.
120: Logically Collective
122: Input Parameter:
123: . snes - the `SNES` context
125: Level: advanced
127: Notes:
128: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
130: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
132: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
133: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
135: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
136: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
137: @*/
138: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
139: {
140: PetscFunctionBegin;
142: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates input vector is not in the function domain");
143: snes->domainerror = PETSC_TRUE;
144: PetscFunctionReturn(PETSC_SUCCESS);
145: }
147: /*@
148: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
150: Logically Collective
152: Input Parameter:
153: . snes - the `SNES` context
155: Level: advanced
157: Notes:
158: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
160: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
162: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
163: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
165: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
166: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
167: @*/
168: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
169: {
170: PetscFunctionBegin;
172: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
173: snes->jacobiandomainerror = PETSC_TRUE;
174: PetscFunctionReturn(PETSC_SUCCESS);
175: }
177: /*@
178: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` Jacobian domain error after
179: each Jacobian evaluation. By default, we check Jacobian domain error in the debug mode, and do not check it in the optimized mode.
181: Logically Collective
183: Input Parameters:
184: + snes - the `SNES` context
185: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
187: Level: advanced
189: Note:
190: Checks require one extra parallel synchronization for each Jacobian evaluation
192: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
193: @*/
194: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
195: {
196: PetscFunctionBegin;
198: snes->checkjacdomainerror = flg;
199: PetscFunctionReturn(PETSC_SUCCESS);
200: }
202: /*@
203: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
205: Logically Collective
207: Input Parameter:
208: . snes - the `SNES` context
210: Output Parameter:
211: . flg - `PETSC_FALSE` indicates that we don't check Jacobian domain errors after each Jacobian evaluation
213: Level: advanced
215: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
216: @*/
217: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
218: {
219: PetscFunctionBegin;
221: PetscAssertPointer(flg, 2);
222: *flg = snes->checkjacdomainerror;
223: PetscFunctionReturn(PETSC_SUCCESS);
224: }
226: /*@
227: SNESGetFunctionDomainError - Gets the status of the domain error after a call to `SNESComputeFunction()`;
229: Logically Collective
231: Input Parameter:
232: . snes - the `SNES` context
234: Output Parameter:
235: . domainerror - Set to `PETSC_TRUE` if there's a domain error; `PETSC_FALSE` otherwise.
237: Level: developer
239: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`
240: @*/
241: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
242: {
243: PetscFunctionBegin;
245: PetscAssertPointer(domainerror, 2);
246: *domainerror = snes->domainerror;
247: PetscFunctionReturn(PETSC_SUCCESS);
248: }
250: /*@
251: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to `SNESComputeJacobian()`;
253: Logically Collective
255: Input Parameter:
256: . snes - the `SNES` context
258: Output Parameter:
259: . domainerror - Set to `PETSC_TRUE` if there's a Jacobian domain error; `PETSC_FALSE` otherwise.
261: Level: advanced
263: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`, `SNESGetFunctionDomainError()`
264: @*/
265: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
266: {
267: PetscFunctionBegin;
269: PetscAssertPointer(domainerror, 2);
270: *domainerror = snes->jacobiandomainerror;
271: PetscFunctionReturn(PETSC_SUCCESS);
272: }
274: /*@C
275: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
277: Collective
279: Input Parameters:
280: + snes - the newly loaded `SNES`, this needs to have been created with `SNESCreate()` or
281: some related function before a call to `SNESLoad()`.
282: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
284: Level: intermediate
286: Note:
287: The type is determined by the data in the file, any type set into the `SNES` before this call is ignored.
289: .seealso: [](ch_snes), `SNES`, `PetscViewer`, `SNESCreate()`, `SNESType`, `PetscViewerBinaryOpen()`, `SNESView()`, `MatLoad()`, `VecLoad()`
290: @*/
291: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
292: {
293: PetscBool isbinary;
294: PetscInt classid;
295: char type[256];
296: KSP ksp;
297: DM dm;
298: DMSNES dmsnes;
300: PetscFunctionBegin;
303: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
304: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
306: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
307: PetscCheck(classid == SNES_FILE_CLASSID, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Not SNES next in file");
308: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
309: PetscCall(SNESSetType(snes, type));
310: PetscTryTypeMethod(snes, load, viewer);
311: PetscCall(SNESGetDM(snes, &dm));
312: PetscCall(DMGetDMSNES(dm, &dmsnes));
313: PetscCall(DMSNESLoad(dmsnes, viewer));
314: PetscCall(SNESGetKSP(snes, &ksp));
315: PetscCall(KSPLoad(ksp, viewer));
316: PetscFunctionReturn(PETSC_SUCCESS);
317: }
319: #include <petscdraw.h>
320: #if defined(PETSC_HAVE_SAWS)
321: #include <petscviewersaws.h>
322: #endif
324: /*@C
325: SNESViewFromOptions - View a `SNES` based on values in the options database
327: Collective
329: Input Parameters:
330: + A - the `SNES` context
331: . obj - Optional object that provides the options prefix for the checks
332: - name - command line option
334: Level: intermediate
336: .seealso: [](ch_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
337: @*/
338: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
339: {
340: PetscFunctionBegin;
342: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
343: PetscFunctionReturn(PETSC_SUCCESS);
344: }
346: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
348: /*@C
349: SNESView - Prints or visualizes the `SNES` data structure.
351: Collective
353: Input Parameters:
354: + snes - the `SNES` context
355: - viewer - the `PetscViewer`
357: Options Database Key:
358: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
360: Level: beginner
362: Notes:
363: The available visualization contexts include
364: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
365: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
366: output where only the first processor opens
367: the file. All other processors send their
368: data to the first processor to print.
370: The available formats include
371: + `PETSC_VIEWER_DEFAULT` - standard output (default)
372: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
374: The user can open an alternative visualization context with
375: `PetscViewerASCIIOpen()` - output to a specified file.
377: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
379: .seealso: [](ch_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
380: @*/
381: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
382: {
383: SNESKSPEW *kctx;
384: KSP ksp;
385: SNESLineSearch linesearch;
386: PetscBool iascii, isstring, isbinary, isdraw;
387: DMSNES dmsnes;
388: #if defined(PETSC_HAVE_SAWS)
389: PetscBool issaws;
390: #endif
392: PetscFunctionBegin;
394: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
396: PetscCheckSameComm(snes, 1, viewer, 2);
398: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
399: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
400: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
401: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
402: #if defined(PETSC_HAVE_SAWS)
403: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
404: #endif
405: if (iascii) {
406: SNESNormSchedule normschedule;
407: DM dm;
408: PetscErrorCode (*cJ)(SNES, Vec, Mat, Mat, void *);
409: void *ctx;
410: const char *pre = "";
412: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
413: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
414: if (snes->ops->view) {
415: PetscCall(PetscViewerASCIIPushTab(viewer));
416: PetscUseTypeMethod(snes, view, viewer);
417: PetscCall(PetscViewerASCIIPopTab(viewer));
418: }
419: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
420: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
421: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
422: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
423: PetscCall(SNESGetNormSchedule(snes, &normschedule));
424: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
425: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
426: if (snes->ksp_ewconv) {
427: kctx = (SNESKSPEW *)snes->kspconvctx;
428: if (kctx) {
429: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
430: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
431: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
432: }
433: }
434: if (snes->lagpreconditioner == -1) {
435: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
436: } else if (snes->lagpreconditioner > 1) {
437: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
438: }
439: if (snes->lagjacobian == -1) {
440: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
441: } else if (snes->lagjacobian > 1) {
442: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
443: }
444: PetscCall(SNESGetDM(snes, &dm));
445: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
446: if (snes->mf_operator) {
447: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
448: pre = "Preconditioning ";
449: }
450: if (cJ == SNESComputeJacobianDefault) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
452: } else if (cJ == SNESComputeJacobianDefaultColor) {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
454: /* it slightly breaks data encapsulation for access the DMDA information directly */
455: } else if (cJ == SNESComputeJacobian_DMDA) {
456: MatFDColoring fdcoloring;
457: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
458: if (fdcoloring) {
459: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
460: } else {
461: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
462: }
463: } else if (snes->mf && !snes->mf_operator) {
464: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
465: }
466: } else if (isstring) {
467: const char *type;
468: PetscCall(SNESGetType(snes, &type));
469: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
470: PetscTryTypeMethod(snes, view, viewer);
471: } else if (isbinary) {
472: PetscInt classid = SNES_FILE_CLASSID;
473: MPI_Comm comm;
474: PetscMPIInt rank;
475: char type[256];
477: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
478: PetscCallMPI(MPI_Comm_rank(comm, &rank));
479: if (rank == 0) {
480: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
481: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
482: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
483: }
484: PetscTryTypeMethod(snes, view, viewer);
485: } else if (isdraw) {
486: PetscDraw draw;
487: char str[36];
488: PetscReal x, y, bottom, h;
490: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
491: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
492: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
493: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
494: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
495: bottom = y - h;
496: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
497: PetscTryTypeMethod(snes, view, viewer);
498: #if defined(PETSC_HAVE_SAWS)
499: } else if (issaws) {
500: PetscMPIInt rank;
501: const char *name;
503: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
504: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
505: if (!((PetscObject)snes)->amsmem && rank == 0) {
506: char dir[1024];
508: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
509: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
510: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
511: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
512: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
513: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
514: }
515: #endif
516: }
517: if (snes->linesearch) {
518: PetscCall(SNESGetLineSearch(snes, &linesearch));
519: PetscCall(PetscViewerASCIIPushTab(viewer));
520: PetscCall(SNESLineSearchView(linesearch, viewer));
521: PetscCall(PetscViewerASCIIPopTab(viewer));
522: }
523: if (snes->npc && snes->usesnpc) {
524: PetscCall(PetscViewerASCIIPushTab(viewer));
525: PetscCall(SNESView(snes->npc, viewer));
526: PetscCall(PetscViewerASCIIPopTab(viewer));
527: }
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
530: PetscCall(DMSNESView(dmsnes, viewer));
531: PetscCall(PetscViewerASCIIPopTab(viewer));
532: if (snes->usesksp) {
533: PetscCall(SNESGetKSP(snes, &ksp));
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(KSPView(ksp, viewer));
536: PetscCall(PetscViewerASCIIPopTab(viewer));
537: }
538: if (isdraw) {
539: PetscDraw draw;
540: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
541: PetscCall(PetscDrawPopCurrentPoint(draw));
542: }
543: PetscFunctionReturn(PETSC_SUCCESS);
544: }
546: /*
547: We retain a list of functions that also take SNES command
548: line options. These are called at the end SNESSetFromOptions()
549: */
550: #define MAXSETFROMOPTIONS 5
551: static PetscInt numberofsetfromoptions;
552: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
554: /*@C
555: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
557: Not Collective
559: Input Parameter:
560: . snescheck - function that checks for options
562: Level: developer
564: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
565: @*/
566: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
567: {
568: PetscFunctionBegin;
569: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
570: othersetfromoptions[numberofsetfromoptions++] = snescheck;
571: PetscFunctionReturn(PETSC_SUCCESS);
572: }
574: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
575: {
576: Mat J;
577: MatNullSpace nullsp;
579: PetscFunctionBegin;
582: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
583: Mat A = snes->jacobian, B = snes->jacobian_pre;
584: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
585: }
587: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
588: if (version == 1) {
589: PetscCall(MatCreateSNESMF(snes, &J));
590: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
591: PetscCall(MatSetFromOptions(J));
592: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
593: } else /* if (version == 2) */ {
594: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
595: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
596: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
597: #else
598: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
599: #endif
600: }
602: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
603: if (snes->jacobian) {
604: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
605: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
606: }
608: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
609: if (hasOperator) {
610: /* This version replaces the user provided Jacobian matrix with a
611: matrix-free version but still employs the user-provided preconditioner matrix. */
612: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
613: } else {
614: /* This version replaces both the user-provided Jacobian and the user-
615: provided preconditioner Jacobian with the default matrix-free version. */
616: if (snes->npcside == PC_LEFT && snes->npc) {
617: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
618: } else {
619: KSP ksp;
620: PC pc;
621: PetscBool match;
623: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
624: /* Force no preconditioner */
625: PetscCall(SNESGetKSP(snes, &ksp));
626: PetscCall(KSPGetPC(ksp, &pc));
627: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
628: if (!match) {
629: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
630: PetscCall(PCSetType(pc, PCNONE));
631: }
632: }
633: }
634: PetscCall(MatDestroy(&J));
635: PetscFunctionReturn(PETSC_SUCCESS);
636: }
638: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
639: {
640: SNES snes = (SNES)ctx;
641: Vec Xfine, Xfine_named = NULL, Xcoarse;
643: PetscFunctionBegin;
644: if (PetscLogPrintInfo) {
645: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
646: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
647: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
648: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
649: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
650: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
651: }
652: if (dmfine == snes->dm) Xfine = snes->vec_sol;
653: else {
654: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
655: Xfine = Xfine_named;
656: }
657: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
658: if (Inject) {
659: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
660: } else {
661: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
662: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
663: }
664: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
665: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
666: PetscFunctionReturn(PETSC_SUCCESS);
667: }
669: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
670: {
671: PetscFunctionBegin;
672: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
673: PetscFunctionReturn(PETSC_SUCCESS);
674: }
676: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
677: * safely call SNESGetDM() in their residual evaluation routine. */
678: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
679: {
680: SNES snes = (SNES)ctx;
681: Vec X, Xnamed = NULL;
682: DM dmsave;
683: void *ctxsave;
684: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *) = NULL;
686: PetscFunctionBegin;
687: dmsave = snes->dm;
688: PetscCall(KSPGetDM(ksp, &snes->dm));
689: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
690: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */ PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
691: X = Xnamed;
692: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
693: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
694: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
695: }
696: /* Make sure KSP DM has the Jacobian computation routine */
697: {
698: DMSNES sdm;
700: PetscCall(DMGetDMSNES(snes->dm, &sdm));
701: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
702: }
703: /* Compute the operators */
704: PetscCall(SNESComputeJacobian(snes, X, A, B));
705: /* Put the previous context back */
706: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
708: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
709: snes->dm = dmsave;
710: PetscFunctionReturn(PETSC_SUCCESS);
711: }
713: /*@
714: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
716: Collective
718: Input Parameter:
719: . snes - `SNES` object to configure
721: Level: developer
723: Note:
724: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
726: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
727: @*/
728: PetscErrorCode SNESSetUpMatrices(SNES snes)
729: {
730: DM dm;
731: DMSNES sdm;
733: PetscFunctionBegin;
734: PetscCall(SNESGetDM(snes, &dm));
735: PetscCall(DMGetDMSNES(dm, &sdm));
736: if (!snes->jacobian && snes->mf) {
737: Mat J;
738: void *functx;
739: PetscCall(MatCreateSNESMF(snes, &J));
740: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
741: PetscCall(MatSetFromOptions(J));
742: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
743: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
744: PetscCall(MatDestroy(&J));
745: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
746: Mat J, B;
747: PetscCall(MatCreateSNESMF(snes, &J));
748: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
749: PetscCall(MatSetFromOptions(J));
750: PetscCall(DMCreateMatrix(snes->dm, &B));
751: /* sdm->computejacobian was already set to reach here */
752: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
753: PetscCall(MatDestroy(&J));
754: PetscCall(MatDestroy(&B));
755: } else if (!snes->jacobian_pre) {
756: PetscDS prob;
757: Mat J, B;
758: PetscBool hasPrec = PETSC_FALSE;
760: J = snes->jacobian;
761: PetscCall(DMGetDS(dm, &prob));
762: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
763: if (J) PetscCall(PetscObjectReference((PetscObject)J));
764: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
765: PetscCall(DMCreateMatrix(snes->dm, &B));
766: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
767: PetscCall(MatDestroy(&J));
768: PetscCall(MatDestroy(&B));
769: }
770: {
771: KSP ksp;
772: PetscCall(SNESGetKSP(snes, &ksp));
773: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
774: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
775: }
776: PetscFunctionReturn(PETSC_SUCCESS);
777: }
779: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
780: {
781: PetscInt i;
783: PetscFunctionBegin;
784: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
785: for (i = 0; i < snes->numbermonitors; ++i) {
786: PetscViewerAndFormat *vf = (PetscViewerAndFormat *)snes->monitorcontext[i];
787: PetscDraw draw;
788: PetscReal lpause;
790: if (!vf) continue;
791: if (vf->lg) {
792: if (!PetscCheckPointer(vf->lg, PETSC_OBJECT)) continue;
793: if (((PetscObject)vf->lg)->classid != PETSC_DRAWLG_CLASSID) continue;
794: PetscCall(PetscDrawLGGetDraw(vf->lg, &draw));
795: PetscCall(PetscDrawGetPause(draw, &lpause));
796: PetscCall(PetscDrawSetPause(draw, -1.0));
797: PetscCall(PetscDrawPause(draw));
798: PetscCall(PetscDrawSetPause(draw, lpause));
799: } else {
800: PetscBool isdraw;
802: if (!PetscCheckPointer(vf->viewer, PETSC_OBJECT)) continue;
803: if (((PetscObject)vf->viewer)->classid != PETSC_VIEWER_CLASSID) continue;
804: PetscCall(PetscObjectTypeCompare((PetscObject)vf->viewer, PETSCVIEWERDRAW, &isdraw));
805: if (!isdraw) continue;
806: PetscCall(PetscViewerDrawGetDraw(vf->viewer, 0, &draw));
807: PetscCall(PetscDrawGetPause(draw, &lpause));
808: PetscCall(PetscDrawSetPause(draw, -1.0));
809: PetscCall(PetscDrawPause(draw));
810: PetscCall(PetscDrawSetPause(draw, lpause));
811: }
812: }
813: PetscFunctionReturn(PETSC_SUCCESS);
814: }
816: /*@C
817: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
819: Collective
821: Input Parameters:
822: + snes - `SNES` object you wish to monitor
823: . name - the monitor type one is seeking
824: . help - message indicating what monitoring is done
825: . manual - manual page for the monitor
826: . monitor - the monitor function
827: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the `SNES` or `PetscViewer` objects
829: Options Database Key:
830: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
832: Level: advanced
834: .seealso: [](ch_snes), `PetscOptionsGetViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
835: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
836: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
837: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
838: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
839: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
840: `PetscOptionsFList()`, `PetscOptionsEList()`
841: @*/
842: PetscErrorCode SNESMonitorSetFromOptions(SNES snes, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*monitorsetup)(SNES, PetscViewerAndFormat *))
843: {
844: PetscViewer viewer;
845: PetscViewerFormat format;
846: PetscBool flg;
848: PetscFunctionBegin;
849: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
850: if (flg) {
851: PetscViewerAndFormat *vf;
852: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
853: PetscCall(PetscObjectDereference((PetscObject)viewer));
854: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
855: PetscCall(SNESMonitorSet(snes, (PetscErrorCode(*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode(*)(void **))PetscViewerAndFormatDestroy));
856: }
857: PetscFunctionReturn(PETSC_SUCCESS);
858: }
860: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
861: {
862: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
864: PetscFunctionBegin;
865: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
866: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
867: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
868: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
869: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
870: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
871: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
872: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
873: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
874: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
875: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
876: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
877: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
878: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
879: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
880: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
881: PetscOptionsEnd();
882: PetscFunctionReturn(PETSC_SUCCESS);
883: }
885: /*@
886: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
888: Collective
890: Input Parameter:
891: . snes - the `SNES` context
893: Options Database Keys:
894: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
895: . -snes_stol <stol> - convergence tolerance in terms of the norm of the change in the solution between steps
896: . -snes_atol <abstol> - absolute tolerance of residual norm
897: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
898: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
899: . -snes_force_iteration <force> - force `SNESSolve()` to take at least one iteration
900: . -snes_max_it <max_it> - maximum number of iterations
901: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
902: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
903: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
904: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
905: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
906: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
907: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
908: . -snes_tr_tol <trtol> - trust region tolerance
909: . -snes_convergence_test <default,skip,correct_pressure> - convergence test in nonlinear solver. default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue iterating until max_it or some other criterion is reached, saving expense of convergence test. correct_pressure `SNESConvergedCorrectPressure()` has special handling of a pressure null space.
910: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
911: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
912: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
913: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
914: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
915: . -snes_monitor_lg_range - plots residual norm at each iteration
916: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
917: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
918: . -snes_fd_color - use finite differences with coloring to compute Jacobian
919: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
920: . -snes_converged_reason - print the reason for convergence/divergence after each solve
921: . -npc_snes_type <type> - the `SNES` type to use as a nonlinear preconditioner
922: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one computed via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
923: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian.
925: Options Database Keys for Eisenstat-Walker method:
926: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
927: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
928: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
929: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
930: . -snes_ksp_ew_gamma <gamma> - Sets gamma
931: . -snes_ksp_ew_alpha <alpha> - Sets alpha
932: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
933: - -snes_ksp_ew_threshold <threshold> - Sets threshold
935: Level: beginner
937: Notes:
938: To see all options, run your program with the -help option or consult the users manual
940: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free, and computing explicitly with
941: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
943: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`
944: @*/
945: PetscErrorCode SNESSetFromOptions(SNES snes)
946: {
947: PetscBool flg, pcset, persist, set;
948: PetscInt i, indx, lag, grids;
949: const char *deft = SNESNEWTONLS;
950: const char *convtests[] = {"default", "skip", "correct_pressure"};
951: SNESKSPEW *kctx = NULL;
952: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
953: PCSide pcside;
954: const char *optionsprefix;
956: PetscFunctionBegin;
958: PetscCall(SNESRegisterAll());
959: PetscObjectOptionsBegin((PetscObject)snes);
960: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
961: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
962: if (flg) {
963: PetscCall(SNESSetType(snes, type));
964: } else if (!((PetscObject)snes)->type_name) {
965: PetscCall(SNESSetType(snes, deft));
966: }
967: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &snes->stol, NULL));
968: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &snes->abstol, NULL));
970: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &snes->rtol, NULL));
971: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, NULL));
972: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &snes->max_its, NULL));
973: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &snes->max_funcs, NULL));
974: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, NULL));
975: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, NULL));
976: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
977: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
978: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
980: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
981: if (flg) {
982: PetscCheck(lag != -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_USER, "Cannot set the lag to -1 from the command line since the preconditioner must be built as least once, perhaps you mean -2");
983: PetscCall(SNESSetLagPreconditioner(snes, lag));
984: }
985: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
986: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
987: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
988: if (flg) {
989: PetscCheck(lag != -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_USER, "Cannot set the lag to -1 from the command line since the Jacobian must be built as least once, perhaps you mean -2");
990: PetscCall(SNESSetLagJacobian(snes, lag));
991: }
992: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
993: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
995: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
996: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
998: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
999: if (flg) {
1000: switch (indx) {
1001: case 0:
1002: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1003: break;
1004: case 1:
1005: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1006: break;
1007: case 2:
1008: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1009: break;
1010: }
1011: }
1013: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1014: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1016: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1017: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1019: kctx = (SNESKSPEW *)snes->kspconvctx;
1021: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1023: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1024: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1025: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1027: flg = PETSC_FALSE;
1028: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1029: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1031: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1032: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1033: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1035: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1036: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1037: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1038: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1039: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1040: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1041: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1042: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1044: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1045: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1047: flg = PETSC_FALSE;
1048: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1049: if (flg) {
1050: PetscViewer ctx;
1052: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1053: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscErrorCode(*)(void **))PetscViewerDestroy));
1054: }
1056: flg = PETSC_FALSE;
1057: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1058: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1060: flg = PETSC_FALSE;
1061: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1062: if (flg) {
1063: void *functx;
1064: DM dm;
1065: PetscCall(SNESGetDM(snes, &dm));
1066: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1067: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1068: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1069: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1070: }
1072: flg = PETSC_FALSE;
1073: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1074: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1076: flg = PETSC_FALSE;
1077: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1078: if (flg) {
1079: DM dm;
1080: PetscCall(SNESGetDM(snes, &dm));
1081: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1082: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1083: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1084: }
1086: flg = PETSC_FALSE;
1087: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1088: if (flg && snes->mf_operator) {
1089: snes->mf_operator = PETSC_TRUE;
1090: snes->mf = PETSC_TRUE;
1091: }
1092: flg = PETSC_FALSE;
1093: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1094: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1095: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1097: flg = PETSC_FALSE;
1098: PetscCall(SNESGetNPCSide(snes, &pcside));
1099: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1100: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1102: #if defined(PETSC_HAVE_SAWS)
1103: /*
1104: Publish convergence information using SAWs
1105: */
1106: flg = PETSC_FALSE;
1107: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1108: if (flg) {
1109: void *ctx;
1110: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1111: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1112: }
1113: #endif
1114: #if defined(PETSC_HAVE_SAWS)
1115: {
1116: PetscBool set;
1117: flg = PETSC_FALSE;
1118: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1119: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1120: }
1121: #endif
1123: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1125: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1127: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1128: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1129: PetscOptionsEnd();
1131: if (snes->linesearch) {
1132: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1133: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1134: }
1136: if (snes->usesksp) {
1137: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1138: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1139: PetscCall(KSPSetFromOptions(snes->ksp));
1140: }
1142: /* if user has set the SNES NPC type via options database, create it. */
1143: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1144: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1145: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1146: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1147: snes->setfromoptionscalled++;
1148: PetscFunctionReturn(PETSC_SUCCESS);
1149: }
1151: /*@
1152: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously set from options
1154: Collective
1156: Input Parameter:
1157: . snes - the `SNES` context
1159: Level: beginner
1161: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1162: @*/
1163: PetscErrorCode SNESResetFromOptions(SNES snes)
1164: {
1165: PetscFunctionBegin;
1166: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1167: PetscFunctionReturn(PETSC_SUCCESS);
1168: }
1170: /*@C
1171: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1172: the nonlinear solvers.
1174: Logically Collective; No Fortran Support
1176: Input Parameters:
1177: + snes - the `SNES` context
1178: . compute - function to compute the context
1179: - destroy - function to destroy the context
1181: Level: intermediate
1183: Note:
1184: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1186: Use `SNESSetApplicationContext()` to see the context immediately
1188: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`
1189: @*/
1190: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES, void **), PetscErrorCode (*destroy)(void **))
1191: {
1192: PetscFunctionBegin;
1194: snes->ops->usercompute = compute;
1195: snes->ops->userdestroy = destroy;
1196: PetscFunctionReturn(PETSC_SUCCESS);
1197: }
1199: /*@
1200: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1202: Logically Collective
1204: Input Parameters:
1205: + snes - the `SNES` context
1206: - usrP - optional user context
1208: Level: intermediate
1210: Notes:
1211: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1212: with `SNESGetApplicationContext()`
1214: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1216: Fortran Notes:
1217: You must write a Fortran interface definition for this
1218: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1220: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1221: @*/
1222: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1223: {
1224: KSP ksp;
1226: PetscFunctionBegin;
1228: PetscCall(SNESGetKSP(snes, &ksp));
1229: PetscCall(KSPSetApplicationContext(ksp, usrP));
1230: snes->user = usrP;
1231: PetscFunctionReturn(PETSC_SUCCESS);
1232: }
1234: /*@
1235: SNESGetApplicationContext - Gets the user-defined context for the
1236: nonlinear solvers set with `SNESGetApplicationContext()` or with `SNESSetComputeApplicationContext()`
1238: Not Collective
1240: Input Parameter:
1241: . snes - `SNES` context
1243: Output Parameter:
1244: . usrP - user context
1246: Level: intermediate
1248: Fortran Notes:
1249: You must write a Fortran interface definition for this
1250: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1252: .seealso: [](ch_snes), `SNESSetApplicationContext()`
1253: @*/
1254: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1255: {
1256: PetscFunctionBegin;
1258: *(void **)usrP = snes->user;
1259: PetscFunctionReturn(PETSC_SUCCESS);
1260: }
1262: /*@
1263: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix vector products to apply the Jacobian.
1265: Logically Collective
1267: Input Parameters:
1268: + snes - `SNES` context
1269: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1270: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored. With
1271: this option no matrix element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1273: Options Database Keys:
1274: + -snes_mf_operator - use matrix-free only for the mat operator
1275: . -snes_mf - use matrix-free for both the mat and pmat operator
1276: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1277: - -snes_fd - compute the Jacobian via finite differences (slow)
1279: Level: intermediate
1281: Note:
1282: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free, and computing explicitly with
1283: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1285: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`
1286: @*/
1287: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1288: {
1289: PetscFunctionBegin;
1293: snes->mf = mf_operator ? PETSC_TRUE : mf;
1294: snes->mf_operator = mf_operator;
1295: PetscFunctionReturn(PETSC_SUCCESS);
1296: }
1298: /*@
1299: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1301: Not Collective, but the resulting flags will be the same on all MPI ranks
1303: Input Parameter:
1304: . snes - `SNES` context
1306: Output Parameters:
1307: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1308: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1310: Level: intermediate
1312: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1313: @*/
1314: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1315: {
1316: PetscFunctionBegin;
1318: if (mf) *mf = snes->mf;
1319: if (mf_operator) *mf_operator = snes->mf_operator;
1320: PetscFunctionReturn(PETSC_SUCCESS);
1321: }
1323: /*@
1324: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1325: at this time.
1327: Not Collective
1329: Input Parameter:
1330: . snes - `SNES` context
1332: Output Parameter:
1333: . iter - iteration number
1335: Level: intermediate
1337: Notes:
1338: For example, during the computation of iteration 2 this would return 1.
1340: This is useful for using lagged Jacobians (where one does not recompute the
1341: Jacobian at each `SNES` iteration). For example, the code
1342: .vb
1343: ierr = SNESGetIterationNumber(snes,&it);
1344: if (!(it % 2)) {
1345: [compute Jacobian here]
1346: }
1347: .ve
1348: can be used in your function that computes the Jacobian to cause the Jacobian to be
1349: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1351: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1353: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`
1354: @*/
1355: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1356: {
1357: PetscFunctionBegin;
1359: PetscAssertPointer(iter, 2);
1360: *iter = snes->iter;
1361: PetscFunctionReturn(PETSC_SUCCESS);
1362: }
1364: /*@
1365: SNESSetIterationNumber - Sets the current iteration number.
1367: Not Collective
1369: Input Parameters:
1370: + snes - `SNES` context
1371: - iter - iteration number
1373: Level: developer
1375: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1376: @*/
1377: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1378: {
1379: PetscFunctionBegin;
1381: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1382: snes->iter = iter;
1383: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1384: PetscFunctionReturn(PETSC_SUCCESS);
1385: }
1387: /*@
1388: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1389: attempted by the nonlinear solver.
1391: Not Collective
1393: Input Parameter:
1394: . snes - `SNES` context
1396: Output Parameter:
1397: . nfails - number of unsuccessful steps attempted
1399: Level: intermediate
1401: Note:
1402: This counter is reset to zero for each successive call to `SNESSolve()`.
1404: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1405: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1406: @*/
1407: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1408: {
1409: PetscFunctionBegin;
1411: PetscAssertPointer(nfails, 2);
1412: *nfails = snes->numFailures;
1413: PetscFunctionReturn(PETSC_SUCCESS);
1414: }
1416: /*@
1417: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1418: attempted by the nonlinear solver before it gives up and generates an error
1420: Not Collective
1422: Input Parameters:
1423: + snes - `SNES` context
1424: - maxFails - maximum of unsuccessful steps
1426: Level: intermediate
1428: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1429: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1430: @*/
1431: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1432: {
1433: PetscFunctionBegin;
1435: snes->maxFailures = maxFails;
1436: PetscFunctionReturn(PETSC_SUCCESS);
1437: }
1439: /*@
1440: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1441: attempted by the nonlinear solver before it gives up and generates an error
1443: Not Collective
1445: Input Parameter:
1446: . snes - `SNES` context
1448: Output Parameter:
1449: . maxFails - maximum of unsuccessful steps
1451: Level: intermediate
1453: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1454: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1455: @*/
1456: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1457: {
1458: PetscFunctionBegin;
1460: PetscAssertPointer(maxFails, 2);
1461: *maxFails = snes->maxFailures;
1462: PetscFunctionReturn(PETSC_SUCCESS);
1463: }
1465: /*@
1466: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1467: done by the `SNES` object
1469: Not Collective
1471: Input Parameter:
1472: . snes - `SNES` context
1474: Output Parameter:
1475: . nfuncs - number of evaluations
1477: Level: intermediate
1479: Note:
1480: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1482: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1483: @*/
1484: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1485: {
1486: PetscFunctionBegin;
1488: PetscAssertPointer(nfuncs, 2);
1489: *nfuncs = snes->nfuncs;
1490: PetscFunctionReturn(PETSC_SUCCESS);
1491: }
1493: /*@
1494: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1495: linear solvers.
1497: Not Collective
1499: Input Parameter:
1500: . snes - `SNES` context
1502: Output Parameter:
1503: . nfails - number of failed solves
1505: Options Database Key:
1506: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1508: Level: intermediate
1510: Note:
1511: This counter is reset to zero for each successive call to `SNESSolve()`.
1513: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1514: @*/
1515: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1516: {
1517: PetscFunctionBegin;
1519: PetscAssertPointer(nfails, 2);
1520: *nfails = snes->numLinearSolveFailures;
1521: PetscFunctionReturn(PETSC_SUCCESS);
1522: }
1524: /*@
1525: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1526: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1528: Logically Collective
1530: Input Parameters:
1531: + snes - `SNES` context
1532: - maxFails - maximum allowed linear solve failures
1534: Options Database Key:
1535: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1537: Level: intermediate
1539: Note:
1540: By default this is 0; that is `SNES` returns on the first failed linear solve
1542: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1543: @*/
1544: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1545: {
1546: PetscFunctionBegin;
1549: snes->maxLinearSolveFailures = maxFails;
1550: PetscFunctionReturn(PETSC_SUCCESS);
1551: }
1553: /*@
1554: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1555: are allowed before `SNES` returns as unsuccessful
1557: Not Collective
1559: Input Parameter:
1560: . snes - `SNES` context
1562: Output Parameter:
1563: . maxFails - maximum of unsuccessful solves allowed
1565: Level: intermediate
1567: Note:
1568: By default this is 1; that is `SNES` returns on the first failed linear solve
1570: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1571: @*/
1572: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1573: {
1574: PetscFunctionBegin;
1576: PetscAssertPointer(maxFails, 2);
1577: *maxFails = snes->maxLinearSolveFailures;
1578: PetscFunctionReturn(PETSC_SUCCESS);
1579: }
1581: /*@
1582: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1583: used by the nonlinear solver.
1585: Not Collective
1587: Input Parameter:
1588: . snes - `SNES` context
1590: Output Parameter:
1591: . lits - number of linear iterations
1593: Level: intermediate
1595: Notes:
1596: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1598: If the linear solver fails inside the `SNESSolve()` the iterations for that call to the linear solver are not included. If you wish to count them
1599: then call `KSPGetIterationNumber()` after the failed solve.
1601: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1602: @*/
1603: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1604: {
1605: PetscFunctionBegin;
1607: PetscAssertPointer(lits, 2);
1608: *lits = snes->linear_its;
1609: PetscFunctionReturn(PETSC_SUCCESS);
1610: }
1612: /*@
1613: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1614: are reset every time `SNESSolve()` is called.
1616: Logically Collective
1618: Input Parameters:
1619: + snes - `SNES` context
1620: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1622: Level: developer
1624: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1625: @*/
1626: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1627: {
1628: PetscFunctionBegin;
1631: snes->counters_reset = reset;
1632: PetscFunctionReturn(PETSC_SUCCESS);
1633: }
1635: /*@
1636: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1638: Not Collective, but the `SNES` and `KSP` objects must live on the same MPI_Comm
1640: Input Parameters:
1641: + snes - the `SNES` context
1642: - ksp - the `KSP` context
1644: Level: developer
1646: Notes:
1647: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1648: so this routine is rarely needed.
1650: The `KSP` object that is already in the `SNES` object has its reference count
1651: decreased by one.
1653: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1654: @*/
1655: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1656: {
1657: PetscFunctionBegin;
1660: PetscCheckSameComm(snes, 1, ksp, 2);
1661: PetscCall(PetscObjectReference((PetscObject)ksp));
1662: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1663: snes->ksp = ksp;
1664: PetscFunctionReturn(PETSC_SUCCESS);
1665: }
1667: /*@
1668: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1670: Collective
1672: Input Parameter:
1673: . comm - MPI communicator
1675: Output Parameter:
1676: . outsnes - the new `SNES` context
1678: Options Database Keys:
1679: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1680: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1681: as set by `SNESSetJacobian()`
1682: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1683: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1685: Level: beginner
1687: Developer Notes:
1688: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1689: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1690: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1691: in `SNESView()`.
1693: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1694: by help messages about meaningless `SNES` options.
1696: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1698: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1699: @*/
1700: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1701: {
1702: SNES snes;
1703: SNESKSPEW *kctx;
1705: PetscFunctionBegin;
1706: PetscAssertPointer(outsnes, 2);
1707: *outsnes = NULL;
1708: PetscCall(SNESInitializePackage());
1710: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1712: snes->ops->converged = SNESConvergedDefault;
1713: snes->usesksp = PETSC_TRUE;
1714: snes->tolerancesset = PETSC_FALSE;
1715: snes->max_its = 50;
1716: snes->max_funcs = 10000;
1717: snes->norm = 0.0;
1718: snes->xnorm = 0.0;
1719: snes->ynorm = 0.0;
1720: snes->normschedule = SNES_NORM_ALWAYS;
1721: snes->functype = SNES_FUNCTION_DEFAULT;
1722: snes->rtol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1723: snes->ttol = 0.0;
1724: snes->abstol = PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50;
1725: snes->stol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1726: snes->deltatol = PetscDefined(USE_REAL_SINGLE) ? 1.e-6 : 1.e-12;
1727: snes->divtol = 1.e4;
1728: snes->rnorm0 = 0;
1729: snes->nfuncs = 0;
1730: snes->numFailures = 0;
1731: snes->maxFailures = 1;
1732: snes->linear_its = 0;
1733: snes->lagjacobian = 1;
1734: snes->jac_iter = 0;
1735: snes->lagjac_persist = PETSC_FALSE;
1736: snes->lagpreconditioner = 1;
1737: snes->pre_iter = 0;
1738: snes->lagpre_persist = PETSC_FALSE;
1739: snes->numbermonitors = 0;
1740: snes->numberreasonviews = 0;
1741: snes->data = NULL;
1742: snes->setupcalled = PETSC_FALSE;
1743: snes->ksp_ewconv = PETSC_FALSE;
1744: snes->nwork = 0;
1745: snes->work = NULL;
1746: snes->nvwork = 0;
1747: snes->vwork = NULL;
1748: snes->conv_hist_len = 0;
1749: snes->conv_hist_max = 0;
1750: snes->conv_hist = NULL;
1751: snes->conv_hist_its = NULL;
1752: snes->conv_hist_reset = PETSC_TRUE;
1753: snes->counters_reset = PETSC_TRUE;
1754: snes->vec_func_init_set = PETSC_FALSE;
1755: snes->reason = SNES_CONVERGED_ITERATING;
1756: snes->npcside = PC_RIGHT;
1757: snes->setfromoptionscalled = 0;
1759: snes->mf = PETSC_FALSE;
1760: snes->mf_operator = PETSC_FALSE;
1761: snes->mf_version = 1;
1763: snes->numLinearSolveFailures = 0;
1764: snes->maxLinearSolveFailures = 1;
1766: snes->vizerotolerance = 1.e-8;
1767: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1769: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1770: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1772: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1773: PetscCall(PetscNew(&kctx));
1775: snes->kspconvctx = (void *)kctx;
1776: kctx->version = 2;
1777: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1778: this was too large for some test cases */
1779: kctx->rtol_last = 0.0;
1780: kctx->rtol_max = 0.9;
1781: kctx->gamma = 1.0;
1782: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1783: kctx->alpha2 = kctx->alpha;
1784: kctx->threshold = 0.1;
1785: kctx->lresid_last = 0.0;
1786: kctx->norm_last = 0.0;
1788: kctx->rk_last = 0.0;
1789: kctx->rk_last_2 = 0.0;
1790: kctx->rtol_last_2 = 0.0;
1791: kctx->v4_p1 = 0.1;
1792: kctx->v4_p2 = 0.4;
1793: kctx->v4_p3 = 0.7;
1794: kctx->v4_m1 = 0.8;
1795: kctx->v4_m2 = 0.5;
1796: kctx->v4_m3 = 0.1;
1797: kctx->v4_m4 = 0.5;
1799: *outsnes = snes;
1800: PetscFunctionReturn(PETSC_SUCCESS);
1801: }
1803: /*MC
1804: SNESFunction - Functional form used to convey the nonlinear function to `SNES` in `SNESSetFunction()`
1806: Synopsis:
1807: #include "petscsnes.h"
1808: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1810: Collective
1812: Input Parameters:
1813: + snes - the `SNES` context
1814: . x - state at which to evaluate residual
1815: - ctx - optional user-defined function context, passed in with `SNESSetFunction()`
1817: Output Parameter:
1818: . f - vector to put residual (function value)
1820: Level: intermediate
1822: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESGetFunction()`
1823: M*/
1825: /*@C
1826: SNESSetFunction - Sets the function evaluation routine and function
1827: vector for use by the `SNES` routines in solving systems of nonlinear
1828: equations.
1830: Logically Collective
1832: Input Parameters:
1833: + snes - the `SNES` context
1834: . r - vector to store function values, may be `NULL`
1835: . f - function evaluation routine; for calling sequence see `SNESFunction`
1836: - ctx - [optional] user-defined context for private data for the
1837: function evaluation routine (may be `NULL`)
1839: Level: beginner
1841: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunction`
1842: @*/
1843: PetscErrorCode SNESSetFunction(SNES snes, Vec r, PetscErrorCode (*f)(SNES, Vec, Vec, void *), void *ctx)
1844: {
1845: DM dm;
1847: PetscFunctionBegin;
1849: if (r) {
1851: PetscCheckSameComm(snes, 1, r, 2);
1852: PetscCall(PetscObjectReference((PetscObject)r));
1853: PetscCall(VecDestroy(&snes->vec_func));
1854: snes->vec_func = r;
1855: }
1856: PetscCall(SNESGetDM(snes, &dm));
1857: PetscCall(DMSNESSetFunction(dm, f, ctx));
1858: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1859: PetscFunctionReturn(PETSC_SUCCESS);
1860: }
1862: /*@C
1863: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1865: Logically Collective
1867: Input Parameters:
1868: + snes - the `SNES` context
1869: - f - vector to store function value
1871: Level: developer
1873: Notes:
1874: This should not be modified during the solution procedure.
1876: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1878: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1879: @*/
1880: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1881: {
1882: Vec vec_func;
1884: PetscFunctionBegin;
1887: PetscCheckSameComm(snes, 1, f, 2);
1888: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1889: snes->vec_func_init_set = PETSC_FALSE;
1890: PetscFunctionReturn(PETSC_SUCCESS);
1891: }
1892: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1893: PetscCall(VecCopy(f, vec_func));
1895: snes->vec_func_init_set = PETSC_TRUE;
1896: PetscFunctionReturn(PETSC_SUCCESS);
1897: }
1899: /*@
1900: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1901: of the `SNES` method, when norms are computed in the solving process
1903: Logically Collective
1905: Input Parameters:
1906: + snes - the `SNES` context
1907: - normschedule - the frequency of norm computation
1909: Options Database Key:
1910: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1912: Level: advanced
1914: Notes:
1915: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
1916: of the nonlinear function and the taking of its norm at every iteration to
1917: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1918: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
1919: may either be monitored for convergence or not. As these are often used as nonlinear
1920: preconditioners, monitoring the norm of their error is not a useful enterprise within
1921: their solution.
1923: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
1924: @*/
1925: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1926: {
1927: PetscFunctionBegin;
1929: snes->normschedule = normschedule;
1930: PetscFunctionReturn(PETSC_SUCCESS);
1931: }
1933: /*@
1934: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
1935: of the `SNES` method.
1937: Logically Collective
1939: Input Parameters:
1940: + snes - the `SNES` context
1941: - normschedule - the type of the norm used
1943: Level: advanced
1945: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1946: @*/
1947: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1948: {
1949: PetscFunctionBegin;
1951: *normschedule = snes->normschedule;
1952: PetscFunctionReturn(PETSC_SUCCESS);
1953: }
1955: /*@
1956: SNESSetFunctionNorm - Sets the last computed residual norm.
1958: Logically Collective
1960: Input Parameters:
1961: + snes - the `SNES` context
1962: - norm - the value of the norm
1964: Level: developer
1966: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1967: @*/
1968: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1969: {
1970: PetscFunctionBegin;
1972: snes->norm = norm;
1973: PetscFunctionReturn(PETSC_SUCCESS);
1974: }
1976: /*@
1977: SNESGetFunctionNorm - Gets the last computed norm of the residual
1979: Not Collective
1981: Input Parameter:
1982: . snes - the `SNES` context
1984: Output Parameter:
1985: . norm - the last computed residual norm
1987: Level: developer
1989: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1990: @*/
1991: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1992: {
1993: PetscFunctionBegin;
1995: PetscAssertPointer(norm, 2);
1996: *norm = snes->norm;
1997: PetscFunctionReturn(PETSC_SUCCESS);
1998: }
2000: /*@
2001: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2003: Not Collective
2005: Input Parameter:
2006: . snes - the `SNES` context
2008: Output Parameter:
2009: . ynorm - the last computed update norm
2011: Level: developer
2013: Note:
2014: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2016: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2017: @*/
2018: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2019: {
2020: PetscFunctionBegin;
2022: PetscAssertPointer(ynorm, 2);
2023: *ynorm = snes->ynorm;
2024: PetscFunctionReturn(PETSC_SUCCESS);
2025: }
2027: /*@
2028: SNESGetSolutionNorm - Gets the last computed norm of the solution
2030: Not Collective
2032: Input Parameter:
2033: . snes - the `SNES` context
2035: Output Parameter:
2036: . xnorm - the last computed solution norm
2038: Level: developer
2040: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2041: @*/
2042: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2043: {
2044: PetscFunctionBegin;
2046: PetscAssertPointer(xnorm, 2);
2047: *xnorm = snes->xnorm;
2048: PetscFunctionReturn(PETSC_SUCCESS);
2049: }
2051: /*@C
2052: SNESSetFunctionType - Sets the `SNESFunctionType`
2053: of the `SNES` method.
2055: Logically Collective
2057: Input Parameters:
2058: + snes - the `SNES` context
2059: - type - the function type
2061: Level: developer
2063: Notes:
2064: Possible values of the function type
2065: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2066: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2067: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2069: Different `SNESType`s use this value in different ways
2071: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2072: @*/
2073: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2074: {
2075: PetscFunctionBegin;
2077: snes->functype = type;
2078: PetscFunctionReturn(PETSC_SUCCESS);
2079: }
2081: /*@C
2082: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2083: of the SNES method.
2085: Logically Collective
2087: Input Parameters:
2088: + snes - the `SNES` context
2089: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2091: Level: advanced
2093: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2094: @*/
2095: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2096: {
2097: PetscFunctionBegin;
2099: *type = snes->functype;
2100: PetscFunctionReturn(PETSC_SUCCESS);
2101: }
2103: /*@C
2104: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2105: use with composed nonlinear solvers.
2107: Input Parameters:
2108: + snes - the `SNES` context
2109: . f - function evaluation routine to apply Gauss-Seidel
2110: - ctx - [optional] user-defined context for private data for the
2111: smoother evaluation routine (may be `NULL`)
2113: Calling sequence of `f`:
2114: $ PetscErrorCode f(SNES snes, Vec X, Vec B, void *ctx);
2115: + snes - the `SNES` context
2116: . X - the current solution
2117: . B - the right hand side vector (which may be `NULL`)
2118: - ctx - a user provided context
2120: Level: intermediate
2122: Note:
2123: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2124: a problem appropriate update to the solution, particularly `SNESFAS`.
2126: .seealso: [](ch_snes), `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`
2127: @*/
2128: PetscErrorCode SNESSetNGS(SNES snes, PetscErrorCode (*f)(SNES snes, Vec X, Vec B, void *ctx), void *ctx)
2129: {
2130: DM dm;
2132: PetscFunctionBegin;
2134: PetscCall(SNESGetDM(snes, &dm));
2135: PetscCall(DMSNESSetNGS(dm, f, ctx));
2136: PetscFunctionReturn(PETSC_SUCCESS);
2137: }
2139: /*
2140: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2141: changed during the KSPSolve()
2142: */
2143: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2144: {
2145: DM dm;
2146: DMSNES sdm;
2148: PetscFunctionBegin;
2149: PetscCall(SNESGetDM(snes, &dm));
2150: PetscCall(DMGetDMSNES(dm, &sdm));
2151: /* A(x)*x - b(x) */
2152: if (sdm->ops->computepfunction) {
2153: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2154: PetscCall(VecScale(f, -1.0));
2155: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2156: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2157: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2158: PetscCall(MatMultAdd(snes->picard, x, f, f));
2159: } else {
2160: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2161: PetscCall(MatMult(snes->picard, x, f));
2162: }
2163: PetscFunctionReturn(PETSC_SUCCESS);
2164: }
2166: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2167: {
2168: DM dm;
2169: DMSNES sdm;
2171: PetscFunctionBegin;
2172: PetscCall(SNESGetDM(snes, &dm));
2173: PetscCall(DMGetDMSNES(dm, &sdm));
2174: /* A(x)*x - b(x) */
2175: if (sdm->ops->computepfunction) {
2176: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2177: PetscCall(VecScale(f, -1.0));
2178: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2179: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2180: } else {
2181: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2182: PetscCall(MatMult(snes->jacobian_pre, x, f));
2183: }
2184: PetscFunctionReturn(PETSC_SUCCESS);
2185: }
2187: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2188: {
2189: PetscFunctionBegin;
2190: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2191: /* must assembly if matrix-free to get the last SNES solution */
2192: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2193: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2194: PetscFunctionReturn(PETSC_SUCCESS);
2195: }
2197: /*@C
2198: SNESSetPicard - Use `SNES` to solve the system A(x) x = bp(x) + b via a Picard type iteration (Picard linearization)
2200: Logically Collective
2202: Input Parameters:
2203: + snes - the `SNES` context
2204: . r - vector to store function values, may be `NULL`
2205: . bp - function evaluation routine, may be `NULL`
2206: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2207: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2208: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFunction()`
2209: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2211: Level: intermediate
2213: Notes:
2214: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2215: an approximate Newton solver. This interface is provided to allow porting/testing a previous Picard based code in PETSc before converting it to approximate Newton.
2217: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2219: Solves the equation A(x) x = bp(x) - b via the defect correction algorithm A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}.
2220: When an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = bp(x^{n}) + b iteration.
2222: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2224: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2225: the direct Picard iteration A(x^n) x^{n+1} = bp(x^n) + b
2227: There is some controversity over the definition of a Picard iteration for nonlinear systems but almost everyone agrees that it involves a linear solve and some
2228: believe it is the iteration A(x^{n}) x^{n+1} = b(x^{n}) hence we use the name Picard. If anyone has an authoritative reference that defines the Picard iteration
2229: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2231: When used with `-snes_mf_operator` this will run matrix-free Newton's method where the matrix-vector product is of the true Jacobian of A(x)x - bp(x) -b and
2232: A(x^{n}) is used to build the preconditioner
2234: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at at time) and thus represent Newton's method.
2236: When used with `-snes_fd_coloring` this will compute the Jacobian via coloring and thus represent a faster implementation of Newton's method. But the
2237: the nonzero structure of the Jacobian is, in general larger than that of the Picard matrix A so you must provide in A the needed nonzero structure for the correct
2238: coloring. When using `DMDA` this may mean creating the matrix A with `DMCreateMatrix()` using a wider stencil than strictly needed for A or with a `DMDA_STENCIL_BOX`.
2239: See the comment in src/snes/tutorials/ex15.c.
2241: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`, `SNESJacobianFunction`
2242: @*/
2243: PetscErrorCode SNESSetPicard(SNES snes, Vec r, PetscErrorCode (*bp)(SNES, Vec, Vec, void *), Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
2244: {
2245: DM dm;
2247: PetscFunctionBegin;
2249: PetscCall(SNESGetDM(snes, &dm));
2250: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2251: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2252: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2253: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2254: PetscFunctionReturn(PETSC_SUCCESS);
2255: }
2257: /*@C
2258: SNESGetPicard - Returns the context for the Picard iteration
2260: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2262: Input Parameter:
2263: . snes - the `SNES` context
2265: Output Parameters:
2266: + r - the function (or `NULL`)
2267: . f - the function (or `NULL`); for calling sequence see `SNESFunction`
2268: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2269: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2270: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFunction`
2271: - ctx - the function context (or `NULL`)
2273: Level: advanced
2275: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunction`, `SNESJacobianFunction`
2276: @*/
2277: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
2278: {
2279: DM dm;
2281: PetscFunctionBegin;
2283: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2284: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2285: PetscCall(SNESGetDM(snes, &dm));
2286: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2287: PetscFunctionReturn(PETSC_SUCCESS);
2288: }
2290: /*@C
2291: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2293: Logically Collective
2295: Input Parameters:
2296: + snes - the `SNES` context
2297: . func - function evaluation routine
2298: - ctx - [optional] user-defined context for private data for the
2299: function evaluation routine (may be `NULL`)
2301: Calling sequence of `func`:
2302: $ PetscErrorCode func(SNES snes, Vec x, void *ctx);
2303: + snes - the `SNES` solver
2304: . x - vector to put initial guess
2305: - ctx - optional user-defined function context
2307: Level: intermediate
2309: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`
2310: @*/
2311: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, PetscErrorCode (*func)(SNES snes, Vec x, void *ctx), void *ctx)
2312: {
2313: PetscFunctionBegin;
2315: if (func) snes->ops->computeinitialguess = func;
2316: if (ctx) snes->initialguessP = ctx;
2317: PetscFunctionReturn(PETSC_SUCCESS);
2318: }
2320: /*@C
2321: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2322: it assumes a zero right hand side.
2324: Logically Collective
2326: Input Parameter:
2327: . snes - the `SNES` context
2329: Output Parameter:
2330: . rhs - the right hand side vector or `NULL` if the right hand side vector is null
2332: Level: intermediate
2334: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2335: @*/
2336: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2337: {
2338: PetscFunctionBegin;
2340: PetscAssertPointer(rhs, 2);
2341: *rhs = snes->vec_rhs;
2342: PetscFunctionReturn(PETSC_SUCCESS);
2343: }
2345: /*@
2346: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2348: Collective
2350: Input Parameters:
2351: + snes - the `SNES` context
2352: - x - input vector
2354: Output Parameter:
2355: . y - function vector, as set by `SNESSetFunction()`
2357: Level: developer
2359: Note:
2360: `SNESComputeFunction()` is typically used within nonlinear solvers
2361: implementations, so users would not generally call this routine themselves.
2363: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2364: @*/
2365: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2366: {
2367: DM dm;
2368: DMSNES sdm;
2370: PetscFunctionBegin;
2374: PetscCheckSameComm(snes, 1, x, 2);
2375: PetscCheckSameComm(snes, 1, y, 3);
2376: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2378: PetscCall(SNESGetDM(snes, &dm));
2379: PetscCall(DMGetDMSNES(dm, &sdm));
2380: PetscCheck(sdm->ops->computefunction || snes->vec_rhs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2381: if (sdm->ops->computefunction) {
2382: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2383: PetscCall(VecLockReadPush(x));
2384: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2385: snes->domainerror = PETSC_FALSE;
2386: {
2387: void *ctx;
2388: PetscErrorCode (*computefunction)(SNES, Vec, Vec, void *);
2389: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2390: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2391: }
2392: PetscCall(VecLockReadPop(x));
2393: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2394: } else /* if (snes->vec_rhs) */ {
2395: PetscCall(MatMult(snes->jacobian, x, y));
2396: }
2397: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2398: snes->nfuncs++;
2399: /*
2400: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2401: propagate the value to all processes
2402: */
2403: if (snes->domainerror) PetscCall(VecSetInf(y));
2404: PetscFunctionReturn(PETSC_SUCCESS);
2405: }
2407: /*@
2408: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2410: Collective
2412: Input Parameters:
2413: + snes - the `SNES` context
2414: - x - input vector
2416: Output Parameter:
2417: . y - function vector, as set by `SNESSetMFFunction()`
2419: Level: developer
2421: Notes:
2422: `SNESComputeMFFunction()` is used within the matrix vector products called by the matrix created with `MatCreateSNESMF()`
2423: so users would not generally call this routine themselves.
2425: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with `SNESSolve()`
2426: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2427: same function as `SNESComputeFunction()` if a `SNESSolve()` right hand side vector is use because the two functions difference would include this right hand side function.
2429: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2430: @*/
2431: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2432: {
2433: DM dm;
2434: DMSNES sdm;
2436: PetscFunctionBegin;
2440: PetscCheckSameComm(snes, 1, x, 2);
2441: PetscCheckSameComm(snes, 1, y, 3);
2442: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2444: PetscCall(SNESGetDM(snes, &dm));
2445: PetscCall(DMGetDMSNES(dm, &sdm));
2446: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2447: PetscCall(VecLockReadPush(x));
2448: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2449: snes->domainerror = PETSC_FALSE;
2450: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2451: PetscCall(VecLockReadPop(x));
2452: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2453: snes->nfuncs++;
2454: /*
2455: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2456: propagate the value to all processes
2457: */
2458: if (snes->domainerror) PetscCall(VecSetInf(y));
2459: PetscFunctionReturn(PETSC_SUCCESS);
2460: }
2462: /*@
2463: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2465: Collective
2467: Input Parameters:
2468: + snes - the `SNES` context
2469: . x - input vector
2470: - b - rhs vector
2472: Output Parameter:
2473: . x - new solution vector
2475: Level: developer
2477: Note:
2478: `SNESComputeNGS()` is typically used within composed nonlinear solver
2479: implementations, so most users would not generally call this routine
2480: themselves.
2482: .seealso: [](ch_snes), `SNESNGS`, `SNESSetNGS()`, `SNESComputeFunction()`
2483: @*/
2484: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2485: {
2486: DM dm;
2487: DMSNES sdm;
2489: PetscFunctionBegin;
2493: PetscCheckSameComm(snes, 1, x, 3);
2494: if (b) PetscCheckSameComm(snes, 1, b, 2);
2495: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2496: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2497: PetscCall(SNESGetDM(snes, &dm));
2498: PetscCall(DMGetDMSNES(dm, &sdm));
2499: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2500: if (b) PetscCall(VecLockReadPush(b));
2501: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2502: if (b) PetscCall(VecLockReadPop(b));
2503: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2504: PetscFunctionReturn(PETSC_SUCCESS);
2505: }
2507: PetscErrorCode SNESTestJacobian(SNES snes)
2508: {
2509: Mat A, B, C, D, jacobian;
2510: Vec x = snes->vec_sol, f = snes->vec_func;
2511: PetscReal nrm, gnorm;
2512: PetscReal threshold = 1.e-5;
2513: MatType mattype;
2514: PetscInt m, n, M, N;
2515: void *functx;
2516: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2517: PetscViewer viewer, mviewer;
2518: MPI_Comm comm;
2519: PetscInt tabs;
2520: static PetscBool directionsprinted = PETSC_FALSE;
2521: PetscViewerFormat format;
2523: PetscFunctionBegin;
2524: PetscObjectOptionsBegin((PetscObject)snes);
2525: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2526: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2527: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2528: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2529: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2530: /* Cannot remove the what otherwise would be redundant call to (PetscOptionsReal("-snes_test_jacobian_display_threshold") below because its usage is different than the replacement usage */
2531: PetscCall(PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print));
2532: PetscOptionsEnd();
2533: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2535: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2536: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2537: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2538: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2539: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2540: if (!complete_print && !directionsprinted) {
2541: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2542: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2543: }
2544: if (!directionsprinted) {
2545: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2546: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2547: directionsprinted = PETSC_TRUE;
2548: }
2549: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2551: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2552: if (!flg) jacobian = snes->jacobian;
2553: else jacobian = snes->jacobian_pre;
2555: if (!x) {
2556: PetscCall(MatCreateVecs(jacobian, &x, NULL));
2557: } else {
2558: PetscCall(PetscObjectReference((PetscObject)x));
2559: }
2560: if (!f) {
2561: PetscCall(VecDuplicate(x, &f));
2562: } else {
2563: PetscCall(PetscObjectReference((PetscObject)f));
2564: }
2565: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2566: PetscCall(SNESComputeFunction(snes, x, f));
2567: PetscCall(VecDestroy(&f));
2568: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2569: while (jacobian) {
2570: Mat JT = NULL, Jsave = NULL;
2572: if (istranspose) {
2573: PetscCall(MatCreateTranspose(jacobian, &JT));
2574: Jsave = jacobian;
2575: jacobian = JT;
2576: }
2577: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2578: if (flg) {
2579: A = jacobian;
2580: PetscCall(PetscObjectReference((PetscObject)A));
2581: } else {
2582: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2583: }
2585: PetscCall(MatGetType(A, &mattype));
2586: PetscCall(MatGetSize(A, &M, &N));
2587: PetscCall(MatGetLocalSize(A, &m, &n));
2588: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2589: PetscCall(MatSetType(B, mattype));
2590: PetscCall(MatSetSizes(B, m, n, M, N));
2591: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2592: PetscCall(MatSetUp(B));
2593: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2595: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2596: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2598: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2599: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2600: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2601: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2602: PetscCall(MatDestroy(&D));
2603: if (!gnorm) gnorm = 1; /* just in case */
2604: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2606: if (complete_print) {
2607: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2608: PetscCall(MatView(A, mviewer));
2609: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2610: PetscCall(MatView(B, mviewer));
2611: }
2613: if (threshold_print || complete_print) {
2614: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2615: PetscScalar *cvals;
2616: const PetscInt *bcols;
2617: const PetscScalar *bvals;
2619: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2620: PetscCall(MatSetType(C, mattype));
2621: PetscCall(MatSetSizes(C, m, n, M, N));
2622: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2623: PetscCall(MatSetUp(C));
2624: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2626: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2627: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2629: for (row = Istart; row < Iend; row++) {
2630: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2631: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2632: for (j = 0, cncols = 0; j < bncols; j++) {
2633: if (PetscAbsScalar(bvals[j]) > threshold) {
2634: ccols[cncols] = bcols[j];
2635: cvals[cncols] = bvals[j];
2636: cncols += 1;
2637: }
2638: }
2639: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2640: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2641: PetscCall(PetscFree2(ccols, cvals));
2642: }
2643: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2644: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2645: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2646: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2647: PetscCall(MatDestroy(&C));
2648: }
2649: PetscCall(MatDestroy(&A));
2650: PetscCall(MatDestroy(&B));
2651: PetscCall(MatDestroy(&JT));
2652: if (Jsave) jacobian = Jsave;
2653: if (jacobian != snes->jacobian_pre) {
2654: jacobian = snes->jacobian_pre;
2655: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2656: } else jacobian = NULL;
2657: }
2658: PetscCall(VecDestroy(&x));
2659: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2660: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2661: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2662: PetscFunctionReturn(PETSC_SUCCESS);
2663: }
2665: /*@
2666: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2668: Collective
2670: Input Parameters:
2671: + snes - the `SNES` context
2672: - X - input vector
2674: Output Parameters:
2675: + A - Jacobian matrix
2676: - B - optional matrix for building the preconditioner
2678: Options Database Keys:
2679: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2680: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2681: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one compute via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
2682: . -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2683: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2684: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2685: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2686: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2687: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2688: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2689: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2690: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2691: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2692: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2693: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2695: Level: developer
2697: Note:
2698: Most users should not need to explicitly call this routine, as it
2699: is used internally within the nonlinear solvers.
2701: Developer Notes:
2702: This has duplicative ways of checking the accuracy of the user provided Jacobian (see the options above). This is for historical reasons, the routine `SNESTestJacobian()` use to used
2703: for with the `SNESType` of test that has been removed.
2705: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2706: @*/
2707: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2708: {
2709: PetscBool flag;
2710: DM dm;
2711: DMSNES sdm;
2712: KSP ksp;
2714: PetscFunctionBegin;
2717: PetscCheckSameComm(snes, 1, X, 2);
2718: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2719: PetscCall(SNESGetDM(snes, &dm));
2720: PetscCall(DMGetDMSNES(dm, &sdm));
2722: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2723: if (snes->lagjacobian == -2) {
2724: snes->lagjacobian = -1;
2726: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2727: } else if (snes->lagjacobian == -1) {
2728: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2729: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2730: if (flag) {
2731: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2732: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2733: }
2734: PetscFunctionReturn(PETSC_SUCCESS);
2735: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2736: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2737: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2738: if (flag) {
2739: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2740: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2741: }
2742: PetscFunctionReturn(PETSC_SUCCESS);
2743: }
2744: if (snes->npc && snes->npcside == PC_LEFT) {
2745: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2746: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2747: PetscFunctionReturn(PETSC_SUCCESS);
2748: }
2750: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2751: PetscCall(VecLockReadPush(X));
2752: {
2753: void *ctx;
2754: PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *);
2755: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2756: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2757: }
2758: PetscCall(VecLockReadPop(X));
2759: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2761: /* attach latest linearization point to the preconditioning matrix */
2762: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2764: /* the next line ensures that snes->ksp exists */
2765: PetscCall(SNESGetKSP(snes, &ksp));
2766: if (snes->lagpreconditioner == -2) {
2767: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2768: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2769: snes->lagpreconditioner = -1;
2770: } else if (snes->lagpreconditioner == -1) {
2771: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2772: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2773: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2774: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2775: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2776: } else {
2777: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2778: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2779: }
2781: PetscCall(SNESTestJacobian(snes));
2782: /* make sure user returned a correct Jacobian and preconditioner */
2785: {
2786: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2787: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2788: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2789: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2790: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2791: if (flag || flag_draw || flag_contour) {
2792: Mat Bexp_mine = NULL, Bexp, FDexp;
2793: PetscViewer vdraw, vstdout;
2794: PetscBool flg;
2795: if (flag_operator) {
2796: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2797: Bexp = Bexp_mine;
2798: } else {
2799: /* See if the preconditioning matrix can be viewed and added directly */
2800: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2801: if (flg) Bexp = B;
2802: else {
2803: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2804: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2805: Bexp = Bexp_mine;
2806: }
2807: }
2808: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2809: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2810: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2811: if (flag_draw || flag_contour) {
2812: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2813: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2814: } else vdraw = NULL;
2815: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2816: if (flag) PetscCall(MatView(Bexp, vstdout));
2817: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2818: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2819: if (flag) PetscCall(MatView(FDexp, vstdout));
2820: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2821: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2822: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2823: if (flag) PetscCall(MatView(FDexp, vstdout));
2824: if (vdraw) { /* Always use contour for the difference */
2825: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2826: PetscCall(MatView(FDexp, vdraw));
2827: PetscCall(PetscViewerPopFormat(vdraw));
2828: }
2829: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2830: PetscCall(PetscViewerDestroy(&vdraw));
2831: PetscCall(MatDestroy(&Bexp_mine));
2832: PetscCall(MatDestroy(&FDexp));
2833: }
2834: }
2835: {
2836: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2837: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2838: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2839: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2840: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2841: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2842: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2843: if (flag_threshold) {
2844: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2845: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2846: }
2847: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2848: Mat Bfd;
2849: PetscViewer vdraw, vstdout;
2850: MatColoring coloring;
2851: ISColoring iscoloring;
2852: MatFDColoring matfdcoloring;
2853: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
2854: void *funcctx;
2855: PetscReal norm1, norm2, normmax;
2857: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2858: PetscCall(MatColoringCreate(Bfd, &coloring));
2859: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2860: PetscCall(MatColoringSetFromOptions(coloring));
2861: PetscCall(MatColoringApply(coloring, &iscoloring));
2862: PetscCall(MatColoringDestroy(&coloring));
2863: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2864: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2865: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2866: PetscCall(ISColoringDestroy(&iscoloring));
2868: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2869: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
2870: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
2871: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
2872: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
2873: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2874: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
2875: PetscCall(MatFDColoringDestroy(&matfdcoloring));
2877: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2878: if (flag_draw || flag_contour) {
2879: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2880: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2881: } else vdraw = NULL;
2882: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
2883: if (flag_display) PetscCall(MatView(B, vstdout));
2884: if (vdraw) PetscCall(MatView(B, vdraw));
2885: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
2886: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2887: if (vdraw) PetscCall(MatView(Bfd, vdraw));
2888: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
2889: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
2890: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
2891: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
2892: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
2893: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2894: if (vdraw) { /* Always use contour for the difference */
2895: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2896: PetscCall(MatView(Bfd, vdraw));
2897: PetscCall(PetscViewerPopFormat(vdraw));
2898: }
2899: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2901: if (flag_threshold) {
2902: PetscInt bs, rstart, rend, i;
2903: PetscCall(MatGetBlockSize(B, &bs));
2904: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
2905: for (i = rstart; i < rend; i++) {
2906: const PetscScalar *ba, *ca;
2907: const PetscInt *bj, *cj;
2908: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
2909: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
2910: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
2911: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
2912: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2913: for (j = 0; j < bn; j++) {
2914: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2915: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2916: maxentrycol = bj[j];
2917: maxentry = PetscRealPart(ba[j]);
2918: }
2919: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2920: maxdiffcol = bj[j];
2921: maxdiff = PetscRealPart(ca[j]);
2922: }
2923: if (rdiff > maxrdiff) {
2924: maxrdiffcol = bj[j];
2925: maxrdiff = rdiff;
2926: }
2927: }
2928: if (maxrdiff > 1) {
2929: PetscCall(PetscViewerASCIIPrintf(vstdout, "row %" PetscInt_FMT " (maxentry=%g at %" PetscInt_FMT ", maxdiff=%g at %" PetscInt_FMT ", maxrdiff=%g at %" PetscInt_FMT "):", i, (double)maxentry, maxentrycol, (double)maxdiff, maxdiffcol, (double)maxrdiff, maxrdiffcol));
2930: for (j = 0; j < bn; j++) {
2931: PetscReal rdiff;
2932: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2933: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
2934: }
2935: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
2936: }
2937: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
2938: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
2939: }
2940: }
2941: PetscCall(PetscViewerDestroy(&vdraw));
2942: PetscCall(MatDestroy(&Bfd));
2943: }
2944: }
2945: PetscFunctionReturn(PETSC_SUCCESS);
2946: }
2948: /*MC
2949: SNESJacobianFunction - Function used by `SNES` to compute the nonlinear Jacobian of the function to be solved by `SNES`
2951: Synopsis:
2952: #include "petscsnes.h"
2953: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2955: Collective
2957: Input Parameters:
2958: + x - input vector, the Jacobian is to be computed at this value
2959: - ctx - [optional] user-defined Jacobian context
2961: Output Parameters:
2962: + Amat - the matrix that defines the (approximate) Jacobian
2963: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
2965: Level: intermediate
2967: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESSetJacobian()`, `SNESGetJacobian()`
2968: M*/
2970: /*@C
2971: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2972: location to store the matrix.
2974: Logically Collective
2976: Input Parameters:
2977: + snes - the `SNES` context
2978: . Amat - the matrix that defines the (approximate) Jacobian
2979: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
2980: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFunction` for details
2981: - ctx - [optional] user-defined context for private data for the
2982: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
2984: Level: beginner
2986: Notes:
2987: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
2988: each matrix.
2990: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
2991: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
2993: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
2994: must be a `MatFDColoring`.
2996: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
2997: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
2999: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3000: `SNESSetPicard()`, `SNESJacobianFunction`
3001: @*/
3002: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
3003: {
3004: DM dm;
3006: PetscFunctionBegin;
3010: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3011: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3012: PetscCall(SNESGetDM(snes, &dm));
3013: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3014: if (Amat) {
3015: PetscCall(PetscObjectReference((PetscObject)Amat));
3016: PetscCall(MatDestroy(&snes->jacobian));
3018: snes->jacobian = Amat;
3019: }
3020: if (Pmat) {
3021: PetscCall(PetscObjectReference((PetscObject)Pmat));
3022: PetscCall(MatDestroy(&snes->jacobian_pre));
3024: snes->jacobian_pre = Pmat;
3025: }
3026: PetscFunctionReturn(PETSC_SUCCESS);
3027: }
3029: /*@C
3030: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3031: provided context for evaluating the Jacobian.
3033: Not Collective, but `Mat` object will be parallel if `SNES` object is
3035: Input Parameter:
3036: . snes - the nonlinear solver context
3038: Output Parameters:
3039: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3040: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3041: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFunction`
3042: - ctx - location to stash Jacobian ctx (or `NULL`)
3044: Level: advanced
3046: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFunction`, `SNESGetFunction()`
3047: @*/
3048: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
3049: {
3050: DM dm;
3052: PetscFunctionBegin;
3054: if (Amat) *Amat = snes->jacobian;
3055: if (Pmat) *Pmat = snes->jacobian_pre;
3056: PetscCall(SNESGetDM(snes, &dm));
3057: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3058: PetscFunctionReturn(PETSC_SUCCESS);
3059: }
3061: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3062: {
3063: DM dm;
3064: DMSNES sdm;
3066: PetscFunctionBegin;
3067: PetscCall(SNESGetDM(snes, &dm));
3068: PetscCall(DMGetDMSNES(dm, &sdm));
3069: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3070: DM dm;
3071: PetscBool isdense, ismf;
3073: PetscCall(SNESGetDM(snes, &dm));
3074: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3075: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3076: if (isdense) {
3077: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3078: } else if (!ismf) {
3079: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3080: }
3081: }
3082: PetscFunctionReturn(PETSC_SUCCESS);
3083: }
3085: /*@
3086: SNESSetUp - Sets up the internal data structures for the later use
3087: of a nonlinear solver.
3089: Collective
3091: Input Parameter:
3092: . snes - the `SNES` context
3094: Level: advanced
3096: Note:
3097: For basic use of the `SNES` solvers the user need not explicitly call
3098: `SNESSetUp()`, since these actions will automatically occur during
3099: the call to `SNESSolve()`. However, if one wishes to control this
3100: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3101: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3103: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3104: @*/
3105: PetscErrorCode SNESSetUp(SNES snes)
3106: {
3107: DM dm;
3108: DMSNES sdm;
3109: SNESLineSearch linesearch, pclinesearch;
3110: void *lsprectx, *lspostctx;
3111: PetscBool mf_operator, mf;
3112: Vec f, fpc;
3113: void *funcctx;
3114: void *jacctx, *appctx;
3115: Mat j, jpre;
3116: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3117: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3118: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
3119: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *);
3121: PetscFunctionBegin;
3123: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3124: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3126: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3128: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3130: PetscCall(SNESGetDM(snes, &dm));
3131: PetscCall(DMGetDMSNES(dm, &sdm));
3132: PetscCall(SNESSetDefaultComputeJacobian(snes));
3134: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3136: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3138: if (snes->linesearch) {
3139: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3140: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3141: }
3143: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3144: if (snes->npc && snes->npcside == PC_LEFT) {
3145: snes->mf = PETSC_TRUE;
3146: snes->mf_operator = PETSC_FALSE;
3147: }
3149: if (snes->npc) {
3150: /* copy the DM over */
3151: PetscCall(SNESGetDM(snes, &dm));
3152: PetscCall(SNESSetDM(snes->npc, dm));
3154: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3155: PetscCall(VecDuplicate(f, &fpc));
3156: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3157: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3158: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3159: PetscCall(SNESGetApplicationContext(snes, &appctx));
3160: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3161: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3162: PetscCall(VecDestroy(&fpc));
3164: /* copy the function pointers over */
3165: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3167: /* default to 1 iteration */
3168: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3169: if (snes->npcside == PC_RIGHT) {
3170: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3171: } else {
3172: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3173: }
3174: PetscCall(SNESSetFromOptions(snes->npc));
3176: /* copy the line search context over */
3177: if (snes->linesearch && snes->npc->linesearch) {
3178: PetscCall(SNESGetLineSearch(snes, &linesearch));
3179: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3180: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3181: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3182: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3183: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3184: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3185: }
3186: }
3187: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3188: if (snes->ops->usercompute && !snes->user) PetscCall((*snes->ops->usercompute)(snes, (void **)&snes->user));
3190: snes->jac_iter = 0;
3191: snes->pre_iter = 0;
3193: PetscTryTypeMethod(snes, setup);
3195: PetscCall(SNESSetDefaultComputeJacobian(snes));
3197: if (snes->npc && snes->npcside == PC_LEFT) {
3198: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3199: if (snes->linesearch) {
3200: PetscCall(SNESGetLineSearch(snes, &linesearch));
3201: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3202: }
3203: }
3204: }
3205: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3206: snes->setupcalled = PETSC_TRUE;
3207: PetscFunctionReturn(PETSC_SUCCESS);
3208: }
3210: /*@
3211: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3213: Collective
3215: Input Parameter:
3216: . snes - iterative context obtained from `SNESCreate()`
3218: Level: intermediate
3220: Notes:
3221: Call this if you wish to reuse a `SNES` but with different size vectors
3223: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3225: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3226: @*/
3227: PetscErrorCode SNESReset(SNES snes)
3228: {
3229: PetscFunctionBegin;
3231: if (snes->ops->userdestroy && snes->user) {
3232: PetscCall((*snes->ops->userdestroy)((void **)&snes->user));
3233: snes->user = NULL;
3234: }
3235: if (snes->npc) PetscCall(SNESReset(snes->npc));
3237: PetscTryTypeMethod(snes, reset);
3238: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3240: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3242: PetscCall(VecDestroy(&snes->vec_rhs));
3243: PetscCall(VecDestroy(&snes->vec_sol));
3244: PetscCall(VecDestroy(&snes->vec_sol_update));
3245: PetscCall(VecDestroy(&snes->vec_func));
3246: PetscCall(MatDestroy(&snes->jacobian));
3247: PetscCall(MatDestroy(&snes->jacobian_pre));
3248: PetscCall(MatDestroy(&snes->picard));
3249: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3250: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3252: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3254: snes->nwork = snes->nvwork = 0;
3255: snes->setupcalled = PETSC_FALSE;
3256: PetscFunctionReturn(PETSC_SUCCESS);
3257: }
3259: /*@
3260: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object.
3262: Collective
3264: Input Parameter:
3265: . snes - iterative context obtained from `SNESCreate()`
3267: Level: intermediate
3269: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`
3270: @*/
3271: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3272: {
3273: PetscInt i;
3275: PetscFunctionBegin;
3277: for (i = 0; i < snes->numberreasonviews; i++) {
3278: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3279: }
3280: snes->numberreasonviews = 0;
3281: PetscFunctionReturn(PETSC_SUCCESS);
3282: }
3284: /*@C
3285: SNESDestroy - Destroys the nonlinear solver context that was created
3286: with `SNESCreate()`.
3288: Collective
3290: Input Parameter:
3291: . snes - the `SNES` context
3293: Level: beginner
3295: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3296: @*/
3297: PetscErrorCode SNESDestroy(SNES *snes)
3298: {
3299: PetscFunctionBegin;
3300: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3302: if (--((PetscObject)(*snes))->refct > 0) {
3303: *snes = NULL;
3304: PetscFunctionReturn(PETSC_SUCCESS);
3305: }
3307: PetscCall(SNESReset((*snes)));
3308: PetscCall(SNESDestroy(&(*snes)->npc));
3310: /* if memory was published with SAWs then destroy it */
3311: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3312: PetscTryTypeMethod((*snes), destroy);
3314: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3315: PetscCall(DMDestroy(&(*snes)->dm));
3316: PetscCall(KSPDestroy(&(*snes)->ksp));
3317: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3319: PetscCall(PetscFree((*snes)->kspconvctx));
3320: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3321: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3322: PetscCall(SNESMonitorCancel((*snes)));
3323: PetscCall(SNESConvergedReasonViewCancel((*snes)));
3324: PetscCall(PetscHeaderDestroy(snes));
3325: PetscFunctionReturn(PETSC_SUCCESS);
3326: }
3328: /* ----------- Routines to set solver parameters ---------- */
3330: /*@
3331: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3333: Logically Collective
3335: Input Parameters:
3336: + snes - the `SNES` context
3337: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3338: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3340: Options Database Keys:
3341: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3342: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3343: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3344: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3346: Notes:
3348: Level: intermediate
3350: The default is 1
3351: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3353: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3355: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3356: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3357: @*/
3358: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3359: {
3360: PetscFunctionBegin;
3362: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3363: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3365: snes->lagpreconditioner = lag;
3366: PetscFunctionReturn(PETSC_SUCCESS);
3367: }
3369: /*@
3370: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3372: Logically Collective
3374: Input Parameters:
3375: + snes - the `SNES` context
3376: - steps - the number of refinements to do, defaults to 0
3378: Options Database Key:
3379: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3381: Level: intermediate
3383: Note:
3384: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3386: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`
3387: @*/
3388: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3389: {
3390: PetscFunctionBegin;
3393: snes->gridsequence = steps;
3394: PetscFunctionReturn(PETSC_SUCCESS);
3395: }
3397: /*@
3398: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3400: Logically Collective
3402: Input Parameter:
3403: . snes - the `SNES` context
3405: Output Parameter:
3406: . steps - the number of refinements to do, defaults to 0
3408: Options Database Key:
3409: . -snes_grid_sequence <steps> - set number of refinements
3411: Level: intermediate
3413: Note:
3414: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3416: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3417: @*/
3418: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3419: {
3420: PetscFunctionBegin;
3422: *steps = snes->gridsequence;
3423: PetscFunctionReturn(PETSC_SUCCESS);
3424: }
3426: /*@
3427: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3429: Not Collective
3431: Input Parameter:
3432: . snes - the `SNES` context
3434: Output Parameter:
3435: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3436: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3438: Options Database Keys:
3439: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3440: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3441: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3442: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3444: Level: intermediate
3446: Notes:
3447: The default is 1
3449: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3451: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3452: @*/
3453: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3454: {
3455: PetscFunctionBegin;
3457: *lag = snes->lagpreconditioner;
3458: PetscFunctionReturn(PETSC_SUCCESS);
3459: }
3461: /*@
3462: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3463: often the preconditioner is rebuilt.
3465: Logically Collective
3467: Input Parameters:
3468: + snes - the `SNES` context
3469: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3470: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3472: Options Database Keys:
3473: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3474: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3475: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3476: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3478: Level: intermediate
3480: Notes:
3481: The default is 1
3483: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3485: If -1 is used before the very first nonlinear solve the CODE WILL FAIL! because no Jacobian is used, use -2 to indicate you want it recomputed
3486: at the next Newton step but never again (unless it is reset to another value)
3488: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3489: @*/
3490: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3491: {
3492: PetscFunctionBegin;
3494: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3495: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3497: snes->lagjacobian = lag;
3498: PetscFunctionReturn(PETSC_SUCCESS);
3499: }
3501: /*@
3502: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3504: Not Collective
3506: Input Parameter:
3507: . snes - the `SNES` context
3509: Output Parameter:
3510: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3511: the Jacobian is built etc.
3513: Level: intermediate
3515: Notes:
3516: The default is 1
3518: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3520: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3522: @*/
3523: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3524: {
3525: PetscFunctionBegin;
3527: *lag = snes->lagjacobian;
3528: PetscFunctionReturn(PETSC_SUCCESS);
3529: }
3531: /*@
3532: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3534: Logically collective
3536: Input Parameters:
3537: + snes - the `SNES` context
3538: - flg - jacobian lagging persists if true
3540: Options Database Keys:
3541: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3542: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3543: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3544: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3546: Level: advanced
3548: Notes:
3549: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that.
3551: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3552: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3553: timesteps may present huge efficiency gains.
3555: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3556: @*/
3557: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3558: {
3559: PetscFunctionBegin;
3562: snes->lagjac_persist = flg;
3563: PetscFunctionReturn(PETSC_SUCCESS);
3564: }
3566: /*@
3567: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3569: Logically Collective
3571: Input Parameters:
3572: + snes - the `SNES` context
3573: - flg - preconditioner lagging persists if true
3575: Options Database Keys:
3576: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3577: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3578: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3579: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3581: Level: developer
3583: Notes:
3584: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that.
3586: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3587: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3588: several timesteps may present huge efficiency gains.
3590: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3591: @*/
3592: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3593: {
3594: PetscFunctionBegin;
3597: snes->lagpre_persist = flg;
3598: PetscFunctionReturn(PETSC_SUCCESS);
3599: }
3601: /*@
3602: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3604: Logically Collective
3606: Input Parameters:
3607: + snes - the `SNES` context
3608: - force - `PETSC_TRUE` require at least one iteration
3610: Options Database Key:
3611: . -snes_force_iteration <force> - Sets forcing an iteration
3613: Level: intermediate
3615: Note:
3616: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3618: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3619: @*/
3620: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3621: {
3622: PetscFunctionBegin;
3624: snes->forceiteration = force;
3625: PetscFunctionReturn(PETSC_SUCCESS);
3626: }
3628: /*@
3629: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3631: Logically Collective
3633: Input Parameter:
3634: . snes - the `SNES` context
3636: Output Parameter:
3637: . force - `PETSC_TRUE` requires at least one iteration.
3639: Level: intermediate
3641: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3642: @*/
3643: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3644: {
3645: PetscFunctionBegin;
3647: *force = snes->forceiteration;
3648: PetscFunctionReturn(PETSC_SUCCESS);
3649: }
3651: /*@
3652: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3654: Logically Collective
3656: Input Parameters:
3657: + snes - the `SNES` context
3658: . abstol - absolute convergence tolerance
3659: . rtol - relative convergence tolerance
3660: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3661: . maxit - maximum number of iterations, default 50.
3662: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3664: Options Database Keys:
3665: + -snes_atol <abstol> - Sets abstol
3666: . -snes_rtol <rtol> - Sets rtol
3667: . -snes_stol <stol> - Sets stol
3668: . -snes_max_it <maxit> - Sets maxit
3669: - -snes_max_funcs <maxf> - Sets maxf
3671: Level: intermediate
3673: .seealso: [](ch_snes), `SNESolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3674: @*/
3675: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3676: {
3677: PetscFunctionBegin;
3685: if (abstol != (PetscReal)PETSC_DEFAULT) {
3686: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3687: snes->abstol = abstol;
3688: }
3689: if (rtol != (PetscReal)PETSC_DEFAULT) {
3690: PetscCheck(rtol >= 0.0 && 1.0 > rtol, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Relative tolerance %g must be non-negative and less than 1.0", (double)rtol);
3691: snes->rtol = rtol;
3692: }
3693: if (stol != (PetscReal)PETSC_DEFAULT) {
3694: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3695: snes->stol = stol;
3696: }
3697: if (maxit != PETSC_DEFAULT) {
3698: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3699: snes->max_its = maxit;
3700: }
3701: if (maxf != PETSC_DEFAULT) {
3702: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3703: snes->max_funcs = maxf;
3704: }
3705: snes->tolerancesset = PETSC_TRUE;
3706: PetscFunctionReturn(PETSC_SUCCESS);
3707: }
3709: /*@
3710: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3712: Logically Collective
3714: Input Parameters:
3715: + snes - the `SNES` context
3716: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3718: Options Database Key:
3719: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3721: Level: intermediate
3723: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3724: @*/
3725: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3726: {
3727: PetscFunctionBegin;
3731: if (divtol != (PetscReal)PETSC_DEFAULT) {
3732: snes->divtol = divtol;
3733: } else {
3734: snes->divtol = 1.0e4;
3735: }
3736: PetscFunctionReturn(PETSC_SUCCESS);
3737: }
3739: /*@
3740: SNESGetTolerances - Gets various parameters used in convergence tests.
3742: Not Collective
3744: Input Parameters:
3745: + snes - the `SNES` context
3746: . atol - absolute convergence tolerance
3747: . rtol - relative convergence tolerance
3748: . stol - convergence tolerance in terms of the norm
3749: of the change in the solution between steps
3750: . maxit - maximum number of iterations
3751: - maxf - maximum number of function evaluations
3753: Level: intermediate
3755: Note:
3756: The user can specify `NULL` for any parameter that is not needed.
3758: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3759: @*/
3760: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3761: {
3762: PetscFunctionBegin;
3764: if (atol) *atol = snes->abstol;
3765: if (rtol) *rtol = snes->rtol;
3766: if (stol) *stol = snes->stol;
3767: if (maxit) *maxit = snes->max_its;
3768: if (maxf) *maxf = snes->max_funcs;
3769: PetscFunctionReturn(PETSC_SUCCESS);
3770: }
3772: /*@
3773: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3775: Not Collective
3777: Input Parameters:
3778: + snes - the `SNES` context
3779: - divtol - divergence tolerance
3781: Level: intermediate
3783: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3784: @*/
3785: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3786: {
3787: PetscFunctionBegin;
3789: if (divtol) *divtol = snes->divtol;
3790: PetscFunctionReturn(PETSC_SUCCESS);
3791: }
3793: /*@
3794: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3796: Logically Collective
3798: Input Parameters:
3799: + snes - the `SNES` context
3800: - tol - tolerance
3802: Options Database Key:
3803: . -snes_tr_tol <tol> - Sets tol
3805: Level: intermediate
3807: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
3808: @*/
3809: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3810: {
3811: PetscFunctionBegin;
3814: snes->deltatol = tol;
3815: PetscFunctionReturn(PETSC_SUCCESS);
3816: }
3818: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3820: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3821: {
3822: PetscDrawLG lg;
3823: PetscReal x, y, per;
3824: PetscViewer v = (PetscViewer)monctx;
3825: static PetscReal prev; /* should be in the context */
3826: PetscDraw draw;
3828: PetscFunctionBegin;
3830: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3831: if (!n) PetscCall(PetscDrawLGReset(lg));
3832: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3833: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3834: x = (PetscReal)n;
3835: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3836: else y = -15.0;
3837: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3838: if (n < 20 || !(n % 5) || snes->reason) {
3839: PetscCall(PetscDrawLGDraw(lg));
3840: PetscCall(PetscDrawLGSave(lg));
3841: }
3843: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3844: if (!n) PetscCall(PetscDrawLGReset(lg));
3845: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3846: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
3847: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3848: x = (PetscReal)n;
3849: y = 100.0 * per;
3850: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3851: if (n < 20 || !(n % 5) || snes->reason) {
3852: PetscCall(PetscDrawLGDraw(lg));
3853: PetscCall(PetscDrawLGSave(lg));
3854: }
3856: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3857: if (!n) {
3858: prev = rnorm;
3859: PetscCall(PetscDrawLGReset(lg));
3860: }
3861: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3862: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3863: x = (PetscReal)n;
3864: y = (prev - rnorm) / prev;
3865: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3866: if (n < 20 || !(n % 5) || snes->reason) {
3867: PetscCall(PetscDrawLGDraw(lg));
3868: PetscCall(PetscDrawLGSave(lg));
3869: }
3871: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3872: if (!n) PetscCall(PetscDrawLGReset(lg));
3873: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3874: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3875: x = (PetscReal)n;
3876: y = (prev - rnorm) / (prev * per);
3877: if (n > 2) { /*skip initial crazy value */
3878: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3879: }
3880: if (n < 20 || !(n % 5) || snes->reason) {
3881: PetscCall(PetscDrawLGDraw(lg));
3882: PetscCall(PetscDrawLGSave(lg));
3883: }
3884: prev = rnorm;
3885: PetscFunctionReturn(PETSC_SUCCESS);
3886: }
3888: /*@
3889: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
3891: Collective
3893: Input Parameters:
3894: + snes - the `SNES` context
3895: . it - current iteration
3896: . xnorm - 2-norm of current iterate
3897: . snorm - 2-norm of current step
3898: - fnorm - 2-norm of function
3900: Level: developer
3902: Note:
3903: This routine is called by the `SNES` implementations.
3904: It does not typically need to be called by the user.
3906: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
3907: @*/
3908: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
3909: {
3910: PetscFunctionBegin;
3911: if (!snes->reason) {
3912: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
3913: if (it == snes->max_its && !snes->reason) {
3914: if (snes->normschedule == SNES_NORM_ALWAYS) {
3915: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
3916: snes->reason = SNES_DIVERGED_MAX_IT;
3917: } else snes->reason = SNES_CONVERGED_ITS;
3918: }
3919: }
3920: PetscFunctionReturn(PETSC_SUCCESS);
3921: }
3923: /*@
3924: SNESMonitor - runs the user provided monitor routines, if they exist
3926: Collective
3928: Input Parameters:
3929: + snes - nonlinear solver context obtained from `SNESCreate()`
3930: . iter - iteration number
3931: - rnorm - relative norm of the residual
3933: Level: developer
3935: Note:
3936: This routine is called by the `SNES` implementations.
3937: It does not typically need to be called by the user.
3939: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
3940: @*/
3941: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
3942: {
3943: PetscInt i, n = snes->numbermonitors;
3945: PetscFunctionBegin;
3946: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
3947: PetscCall(VecLockReadPush(snes->vec_sol));
3948: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
3949: PetscCall(VecLockReadPop(snes->vec_sol));
3950: PetscFunctionReturn(PETSC_SUCCESS);
3951: }
3953: /* ------------ Routines to set performance monitoring options ----------- */
3955: /*MC
3956: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
3958: Synopsis:
3959: #include <petscsnes.h>
3960: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
3962: Collective
3964: Input Parameters:
3965: + snes - the `SNES` context
3966: . its - iteration number
3967: . norm - 2-norm function value (may be estimated)
3968: - mctx - [optional] monitoring context
3970: Level: advanced
3972: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
3973: M*/
3975: /*@C
3976: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3977: iteration of the nonlinear solver to display the iteration's
3978: progress.
3980: Logically Collective
3982: Input Parameters:
3983: + snes - the `SNES` context
3984: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
3985: . mctx - [optional] user-defined context for private data for the
3986: monitor routine (use `NULL` if no context is desired)
3987: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
3989: Options Database Keys:
3990: + -snes_monitor - sets `SNESMonitorDefault()`
3991: . -snes_monitor draw::draw_lg - sets line graph monitor,
3992: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
3993: the options database.
3995: Level: intermediate
3997: Note:
3998: Several different monitoring routines may be set by calling
3999: `SNESMonitorSet()` multiple times; all will be called in the
4000: order in which they were set.
4002: Fortran Notes:
4003: Only a single monitor function can be set for each `SNES` object
4005: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4006: @*/
4007: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4008: {
4009: PetscInt i;
4010: PetscBool identical;
4012: PetscFunctionBegin;
4014: for (i = 0; i < snes->numbermonitors; i++) {
4015: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4016: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4017: }
4018: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4019: snes->monitor[snes->numbermonitors] = f;
4020: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4021: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4022: PetscFunctionReturn(PETSC_SUCCESS);
4023: }
4025: /*@
4026: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4028: Logically Collective
4030: Input Parameter:
4031: . snes - the `SNES` context
4033: Options Database Key:
4034: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4035: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4036: set via the options database
4038: Level: intermediate
4040: Note:
4041: There is no way to clear one specific monitor from a `SNES` object.
4043: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4044: @*/
4045: PetscErrorCode SNESMonitorCancel(SNES snes)
4046: {
4047: PetscInt i;
4049: PetscFunctionBegin;
4051: for (i = 0; i < snes->numbermonitors; i++) {
4052: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4053: }
4054: snes->numbermonitors = 0;
4055: PetscFunctionReturn(PETSC_SUCCESS);
4056: }
4058: /*MC
4059: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4061: Synopsis:
4062: #include <petscsnes.h>
4063: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4065: Collective
4067: Input Parameters:
4068: + snes - the `SNES` context
4069: . it - current iteration (0 is the first and is before any Newton step)
4070: . xnorm - 2-norm of current iterate
4071: . gnorm - 2-norm of current step
4072: . f - 2-norm of function
4073: - cctx - [optional] convergence context
4075: Output Parameter:
4076: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4078: Level: intermediate
4080: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4081: M*/
4083: /*@C
4084: SNESSetConvergenceTest - Sets the function that is to be used
4085: to test for convergence of the nonlinear iterative solution.
4087: Logically Collective
4089: Input Parameters:
4090: + snes - the `SNES` context
4091: . SNESConvergenceTestFunction - routine to test for convergence
4092: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4093: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4095: Level: advanced
4097: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4098: @*/
4099: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4100: {
4101: PetscFunctionBegin;
4103: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4104: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4105: snes->ops->converged = SNESConvergenceTestFunction;
4106: snes->ops->convergeddestroy = destroy;
4107: snes->cnvP = cctx;
4108: PetscFunctionReturn(PETSC_SUCCESS);
4109: }
4111: /*@
4112: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4114: Not Collective
4116: Input Parameter:
4117: . snes - the `SNES` context
4119: Output Parameter:
4120: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4122: Options Database Key:
4123: . -snes_converged_reason - prints the reason to standard out
4125: Level: intermediate
4127: Note:
4128: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4130: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4131: @*/
4132: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4133: {
4134: PetscFunctionBegin;
4136: PetscAssertPointer(reason, 2);
4137: *reason = snes->reason;
4138: PetscFunctionReturn(PETSC_SUCCESS);
4139: }
4141: /*@C
4142: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4144: Not Collective
4146: Input Parameter:
4147: . snes - the `SNES` context
4149: Output Parameter:
4150: . strreason - a human readable string that describes `SNES` converged reason
4152: Level: beginner
4154: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4155: @*/
4156: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4157: {
4158: PetscFunctionBegin;
4160: PetscAssertPointer(strreason, 2);
4161: *strreason = SNESConvergedReasons[snes->reason];
4162: PetscFunctionReturn(PETSC_SUCCESS);
4163: }
4165: /*@
4166: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4168: Not Collective
4170: Input Parameters:
4171: + snes - the `SNES` context
4172: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4173: manual pages for the individual convergence tests for complete lists
4175: Level: developer
4177: Developer Notes:
4178: Called inside the various `SNESSolve()` implementations
4180: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4181: @*/
4182: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4183: {
4184: PetscFunctionBegin;
4186: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4187: snes->reason = reason;
4188: PetscFunctionReturn(PETSC_SUCCESS);
4189: }
4191: /*@
4192: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4194: Logically Collective
4196: Input Parameters:
4197: + snes - iterative context obtained from `SNESCreate()`
4198: . a - array to hold history, this array will contain the function norms computed at each step
4199: . its - integer array holds the number of linear iterations for each solve.
4200: . na - size of a and its
4201: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4202: else it continues storing new values for new nonlinear solves after the old ones
4204: Level: intermediate
4206: Notes:
4207: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4208: default array of length 10000 is allocated.
4210: This routine is useful, e.g., when running a code for purposes
4211: of accurate performance monitoring, when no I/O should be done
4212: during the section of code that is being timed.
4214: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4215: @*/
4216: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4217: {
4218: PetscFunctionBegin;
4220: if (a) PetscAssertPointer(a, 2);
4221: if (its) PetscAssertPointer(its, 3);
4222: if (!a) {
4223: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4224: PetscCall(PetscCalloc2(na, &a, na, &its));
4225: snes->conv_hist_alloc = PETSC_TRUE;
4226: }
4227: snes->conv_hist = a;
4228: snes->conv_hist_its = its;
4229: snes->conv_hist_max = (size_t)na;
4230: snes->conv_hist_len = 0;
4231: snes->conv_hist_reset = reset;
4232: PetscFunctionReturn(PETSC_SUCCESS);
4233: }
4235: #if defined(PETSC_HAVE_MATLAB)
4236: #include <engine.h> /* MATLAB include file */
4237: #include <mex.h> /* MATLAB include file */
4239: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4240: {
4241: mxArray *mat;
4242: PetscInt i;
4243: PetscReal *ar;
4245: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4246: ar = (PetscReal *)mxGetData(mat);
4247: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4248: return mat;
4249: }
4250: #endif
4252: /*@C
4253: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4255: Not Collective
4257: Input Parameter:
4258: . snes - iterative context obtained from `SNESCreate()`
4260: Output Parameters:
4261: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4262: . its - integer array holds the number of linear iterations (or
4263: negative if not converged) for each solve.
4264: - na - size of `a` and `its`
4266: Level: intermediate
4268: Note:
4269: This routine is useful, e.g., when running a code for purposes
4270: of accurate performance monitoring, when no I/O should be done
4271: during the section of code that is being timed.
4273: Fortran Notes:
4274: The calling sequence for this routine in Fortran is
4275: .vb
4276: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4277: .ve
4279: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4280: @*/
4281: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4282: {
4283: PetscFunctionBegin;
4285: if (a) *a = snes->conv_hist;
4286: if (its) *its = snes->conv_hist_its;
4287: if (na) *na = (PetscInt)snes->conv_hist_len;
4288: PetscFunctionReturn(PETSC_SUCCESS);
4289: }
4291: /*@C
4292: SNESSetUpdate - Sets the general-purpose update function called
4293: at the beginning of every iteration of the nonlinear solve. Specifically
4294: it is called just before the Jacobian is "evaluated".
4296: Logically Collective
4298: Input Parameters:
4299: + snes - The nonlinear solver context
4300: - func - The function
4302: Calling sequence of `func`:
4303: $ PetscErrorCode func(SNES snes, PetscInt step);
4304: + snes - the nonlinear solver context
4305: - step - The current step of the iteration
4307: Level: advanced
4309: Note:
4310: This is NOT what one uses to update the ghost points before a function evaluation, that should be done at the beginning of your function provided
4311: to `SNESSetFunction()`, or `SNESSetPicard()`
4312: This is not used by most users.
4314: There are a variety of function hooks one many set that are called at different stages of the nonlinear solution process, see the functions listed below.
4316: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4317: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4318: @*/
4319: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt step))
4320: {
4321: PetscFunctionBegin;
4323: snes->ops->update = func;
4324: PetscFunctionReturn(PETSC_SUCCESS);
4325: }
4327: /*@C
4328: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4330: Collective
4332: Input Parameters:
4333: + snes - iterative context obtained from `SNESCreate()`
4334: - viewer - the viewer to display the reason
4336: Options Database Keys:
4337: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4338: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4340: Note:
4341: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4342: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4344: Level: beginner
4346: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4347: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4348: `SNESConvergedReasonViewFromOptions()`,
4349: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4350: @*/
4351: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4352: {
4353: PetscViewerFormat format;
4354: PetscBool isAscii;
4356: PetscFunctionBegin;
4357: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4358: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4359: if (isAscii) {
4360: PetscCall(PetscViewerGetFormat(viewer, &format));
4361: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4362: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4363: DM dm;
4364: Vec u;
4365: PetscDS prob;
4366: PetscInt Nf, f;
4367: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4368: void **exactCtx;
4369: PetscReal error;
4371: PetscCall(SNESGetDM(snes, &dm));
4372: PetscCall(SNESGetSolution(snes, &u));
4373: PetscCall(DMGetDS(dm, &prob));
4374: PetscCall(PetscDSGetNumFields(prob, &Nf));
4375: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4376: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4377: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4378: PetscCall(PetscFree2(exactSol, exactCtx));
4379: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4380: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4381: }
4382: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4383: if (((PetscObject)snes)->prefix) {
4384: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4385: } else {
4386: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4387: }
4388: } else if (snes->reason <= 0) {
4389: if (((PetscObject)snes)->prefix) {
4390: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4391: } else {
4392: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4393: }
4394: }
4395: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4396: }
4397: PetscFunctionReturn(PETSC_SUCCESS);
4398: }
4400: /*@C
4401: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4402: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4404: Logically Collective
4406: Input Parameters:
4407: + snes - the `SNES` context
4408: . f - the snes converged reason view function
4409: . vctx - [optional] user-defined context for private data for the
4410: snes converged reason view routine (use `NULL` if no context is desired)
4411: - reasonviewdestroy - [optional] routine that frees reasonview context (may be `NULL`)
4413: Options Database Keys:
4414: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4415: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have
4416: been hardwired into a code by
4417: calls to `SNESConvergedReasonViewSet()`, but
4418: does not cancel those set via
4419: the options database.
4421: Level: intermediate
4423: Note:
4424: Several different converged reason view routines may be set by calling
4425: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4426: order in which they were set.
4428: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4429: @*/
4430: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES, void *), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **))
4431: {
4432: PetscInt i;
4433: PetscBool identical;
4435: PetscFunctionBegin;
4437: for (i = 0; i < snes->numberreasonviews; i++) {
4438: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4439: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4440: }
4441: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4442: snes->reasonview[snes->numberreasonviews] = f;
4443: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4444: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4445: PetscFunctionReturn(PETSC_SUCCESS);
4446: }
4448: /*@
4449: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed.
4450: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4452: Collective
4454: Input Parameter:
4455: . snes - the `SNES` object
4457: Level: advanced
4459: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4460: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4461: @*/
4462: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4463: {
4464: PetscViewer viewer;
4465: PetscBool flg;
4466: static PetscBool incall = PETSC_FALSE;
4467: PetscViewerFormat format;
4468: PetscInt i;
4470: PetscFunctionBegin;
4471: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4472: incall = PETSC_TRUE;
4474: /* All user-provided viewers are called first, if they exist. */
4475: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4477: /* Call PETSc default routine if users ask for it */
4478: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4479: if (flg) {
4480: PetscCall(PetscViewerPushFormat(viewer, format));
4481: PetscCall(SNESConvergedReasonView(snes, viewer));
4482: PetscCall(PetscViewerPopFormat(viewer));
4483: PetscCall(PetscViewerDestroy(&viewer));
4484: }
4485: incall = PETSC_FALSE;
4486: PetscFunctionReturn(PETSC_SUCCESS);
4487: }
4489: /*@
4490: SNESSolve - Solves a nonlinear system F(x) = b.
4491: Call `SNESSolve()` after calling `SNESCreate()` and optional routines of the form `SNESSetXXX()`.
4493: Collective
4495: Input Parameters:
4496: + snes - the `SNES` context
4497: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4498: - x - the solution vector.
4500: Level: beginner
4502: Note:
4503: The user should initialize the vector,x, with the initial guess
4504: for the nonlinear solve prior to calling `SNESSolve()`. In particular,
4505: to employ an initial guess of zero, the user should explicitly set
4506: this vector to zero by calling `VecSet()`.
4508: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4509: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4510: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4511: @*/
4512: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4513: {
4514: PetscBool flg;
4515: PetscInt grid;
4516: Vec xcreated = NULL;
4517: DM dm;
4519: PetscFunctionBegin;
4522: if (x) PetscCheckSameComm(snes, 1, x, 3);
4524: if (b) PetscCheckSameComm(snes, 1, b, 2);
4526: /* High level operations using the nonlinear solver */
4527: {
4528: PetscViewer viewer;
4529: PetscViewerFormat format;
4530: PetscInt num;
4531: PetscBool flg;
4532: static PetscBool incall = PETSC_FALSE;
4534: if (!incall) {
4535: /* Estimate the convergence rate of the discretization */
4536: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4537: if (flg) {
4538: PetscConvEst conv;
4539: DM dm;
4540: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4541: PetscInt Nf;
4543: incall = PETSC_TRUE;
4544: PetscCall(SNESGetDM(snes, &dm));
4545: PetscCall(DMGetNumFields(dm, &Nf));
4546: PetscCall(PetscCalloc1(Nf, &alpha));
4547: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4548: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4549: PetscCall(PetscConvEstSetFromOptions(conv));
4550: PetscCall(PetscConvEstSetUp(conv));
4551: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4552: PetscCall(PetscViewerPushFormat(viewer, format));
4553: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4554: PetscCall(PetscViewerPopFormat(viewer));
4555: PetscCall(PetscViewerDestroy(&viewer));
4556: PetscCall(PetscConvEstDestroy(&conv));
4557: PetscCall(PetscFree(alpha));
4558: incall = PETSC_FALSE;
4559: }
4560: /* Adaptively refine the initial grid */
4561: num = 1;
4562: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4563: if (flg) {
4564: DMAdaptor adaptor;
4566: incall = PETSC_TRUE;
4567: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4568: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4569: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4570: PetscCall(DMAdaptorSetFromOptions(adaptor));
4571: PetscCall(DMAdaptorSetUp(adaptor));
4572: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4573: PetscCall(DMAdaptorDestroy(&adaptor));
4574: incall = PETSC_FALSE;
4575: }
4576: /* Use grid sequencing to adapt */
4577: num = 0;
4578: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4579: if (num) {
4580: DMAdaptor adaptor;
4582: incall = PETSC_TRUE;
4583: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4584: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4585: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4586: PetscCall(DMAdaptorSetFromOptions(adaptor));
4587: PetscCall(DMAdaptorSetUp(adaptor));
4588: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4589: PetscCall(DMAdaptorDestroy(&adaptor));
4590: incall = PETSC_FALSE;
4591: }
4592: }
4593: }
4594: if (!x) x = snes->vec_sol;
4595: if (!x) {
4596: PetscCall(SNESGetDM(snes, &dm));
4597: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4598: x = xcreated;
4599: }
4600: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4602: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4603: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4604: /* set solution vector */
4605: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4606: PetscCall(VecDestroy(&snes->vec_sol));
4607: snes->vec_sol = x;
4608: PetscCall(SNESGetDM(snes, &dm));
4610: /* set affine vector if provided */
4611: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4612: PetscCall(VecDestroy(&snes->vec_rhs));
4613: snes->vec_rhs = b;
4615: if (snes->vec_rhs) PetscCheck(snes->vec_func != snes->vec_rhs, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Right hand side vector cannot be function vector");
4616: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4617: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right hand side vector");
4618: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4619: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4620: PetscCall(SNESSetUp(snes));
4622: if (!grid) {
4623: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4624: }
4626: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4627: if (snes->counters_reset) {
4628: snes->nfuncs = 0;
4629: snes->linear_its = 0;
4630: snes->numFailures = 0;
4631: }
4633: snes->reason = SNES_CONVERGED_ITERATING;
4634: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4635: PetscUseTypeMethod(snes, solve);
4636: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4637: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4638: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4640: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4641: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4643: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4644: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4645: /* Call converged reason views. This may involve user-provided viewers as well */
4646: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4648: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4649: if (snes->reason < 0) break;
4650: if (grid < snes->gridsequence) {
4651: DM fine;
4652: Vec xnew;
4653: Mat interp;
4655: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4656: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4657: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4658: PetscCall(DMCreateGlobalVector(fine, &xnew));
4659: PetscCall(MatInterpolate(interp, x, xnew));
4660: PetscCall(DMInterpolate(snes->dm, interp, fine));
4661: PetscCall(MatDestroy(&interp));
4662: x = xnew;
4664: PetscCall(SNESReset(snes));
4665: PetscCall(SNESSetDM(snes, fine));
4666: PetscCall(SNESResetFromOptions(snes));
4667: PetscCall(DMDestroy(&fine));
4668: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4669: }
4670: }
4671: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4672: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4673: PetscCall(DMMonitor(snes->dm));
4674: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4676: PetscCall(VecDestroy(&xcreated));
4677: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4678: PetscFunctionReturn(PETSC_SUCCESS);
4679: }
4681: /* --------- Internal routines for SNES Package --------- */
4683: /*@C
4684: SNESSetType - Sets the method for the nonlinear solver.
4686: Collective
4688: Input Parameters:
4689: + snes - the `SNES` context
4690: - type - a known method
4692: Options Database Key:
4693: . -snes_type <type> - Sets the method; use -help for a list
4694: of available methods (for instance, newtonls or newtontr)
4696: Level: intermediate
4698: Notes:
4699: See "petsc/include/petscsnes.h" for available methods (for instance)
4700: + `SNESNEWTONLS` - Newton's method with line search
4701: (systems of nonlinear equations)
4702: - `SNESNEWTONTR` - Newton's method with trust region
4703: (systems of nonlinear equations)
4705: Normally, it is best to use the `SNESSetFromOptions()` command and then
4706: set the `SNES` solver type from the options database rather than by using
4707: this routine. Using the options database provides the user with
4708: maximum flexibility in evaluating the many nonlinear solvers.
4709: The `SNESSetType()` routine is provided for those situations where it
4710: is necessary to set the nonlinear solver independently of the command
4711: line or options database. This might be the case, for example, when
4712: the choice of solver changes during the execution of the program,
4713: and the user's application is taking responsibility for choosing the
4714: appropriate method.
4716: Developer Notes:
4717: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4718: the constructor in that list and calls it to create the specific object.
4720: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4721: @*/
4722: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4723: {
4724: PetscBool match;
4725: PetscErrorCode (*r)(SNES);
4727: PetscFunctionBegin;
4729: PetscAssertPointer(type, 2);
4731: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4732: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4734: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4735: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4736: /* Destroy the previous private SNES context */
4737: PetscTryTypeMethod(snes, destroy);
4738: /* Reinitialize function pointers in SNESOps structure */
4739: snes->ops->setup = NULL;
4740: snes->ops->solve = NULL;
4741: snes->ops->view = NULL;
4742: snes->ops->setfromoptions = NULL;
4743: snes->ops->destroy = NULL;
4745: /* It may happen the user has customized the line search before calling SNESSetType */
4746: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4748: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4749: snes->setupcalled = PETSC_FALSE;
4751: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4752: PetscCall((*r)(snes));
4753: PetscFunctionReturn(PETSC_SUCCESS);
4754: }
4756: /*@C
4757: SNESGetType - Gets the `SNES` method type and name (as a string).
4759: Not Collective
4761: Input Parameter:
4762: . snes - nonlinear solver context
4764: Output Parameter:
4765: . type - `SNES` method (a character string)
4767: Level: intermediate
4769: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4770: @*/
4771: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4772: {
4773: PetscFunctionBegin;
4775: PetscAssertPointer(type, 2);
4776: *type = ((PetscObject)snes)->type_name;
4777: PetscFunctionReturn(PETSC_SUCCESS);
4778: }
4780: /*@
4781: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4783: Logically Collective
4785: Input Parameters:
4786: + snes - the `SNES` context obtained from `SNESCreate()`
4787: - u - the solution vector
4789: Level: beginner
4791: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4792: @*/
4793: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4794: {
4795: DM dm;
4797: PetscFunctionBegin;
4800: PetscCall(PetscObjectReference((PetscObject)u));
4801: PetscCall(VecDestroy(&snes->vec_sol));
4803: snes->vec_sol = u;
4805: PetscCall(SNESGetDM(snes, &dm));
4806: PetscCall(DMShellSetGlobalVector(dm, u));
4807: PetscFunctionReturn(PETSC_SUCCESS);
4808: }
4810: /*@
4811: SNESGetSolution - Returns the vector where the approximate solution is
4812: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4814: Not Collective, but x is parallel if snes is parallel
4816: Input Parameter:
4817: . snes - the `SNES` context
4819: Output Parameter:
4820: . x - the solution
4822: Level: intermediate
4824: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4825: @*/
4826: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4827: {
4828: PetscFunctionBegin;
4830: PetscAssertPointer(x, 2);
4831: *x = snes->vec_sol;
4832: PetscFunctionReturn(PETSC_SUCCESS);
4833: }
4835: /*@
4836: SNESGetSolutionUpdate - Returns the vector where the solution update is
4837: stored.
4839: Not Collective, but x is parallel if snes is parallel
4841: Input Parameter:
4842: . snes - the `SNES` context
4844: Output Parameter:
4845: . x - the solution update
4847: Level: advanced
4849: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4850: @*/
4851: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4852: {
4853: PetscFunctionBegin;
4855: PetscAssertPointer(x, 2);
4856: *x = snes->vec_sol_update;
4857: PetscFunctionReturn(PETSC_SUCCESS);
4858: }
4860: /*@C
4861: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4863: Not Collective, but r is parallel if snes is parallel. Collective if r is requested, but has not been created yet.
4865: Input Parameter:
4866: . snes - the `SNES` context
4868: Output Parameters:
4869: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4870: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunction`
4871: - ctx - the function context (or `NULL` if you don't want it)
4873: Level: advanced
4875: Note:
4876: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4878: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunction`
4879: @*/
4880: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4881: {
4882: DM dm;
4884: PetscFunctionBegin;
4886: if (r) {
4887: if (!snes->vec_func) {
4888: if (snes->vec_rhs) {
4889: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4890: } else if (snes->vec_sol) {
4891: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4892: } else if (snes->dm) {
4893: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4894: }
4895: }
4896: *r = snes->vec_func;
4897: }
4898: PetscCall(SNESGetDM(snes, &dm));
4899: PetscCall(DMSNESGetFunction(dm, f, ctx));
4900: PetscFunctionReturn(PETSC_SUCCESS);
4901: }
4903: /*@C
4904: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
4906: Input Parameter:
4907: . snes - the `SNES` context
4909: Output Parameters:
4910: + f - the function (or `NULL`) see `SNESSetNGS()` for details
4911: - ctx - the function context (or `NULL`)
4913: Level: advanced
4915: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`
4916: @*/
4917: PetscErrorCode SNESGetNGS(SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4918: {
4919: DM dm;
4921: PetscFunctionBegin;
4923: PetscCall(SNESGetDM(snes, &dm));
4924: PetscCall(DMSNESGetNGS(dm, f, ctx));
4925: PetscFunctionReturn(PETSC_SUCCESS);
4926: }
4928: /*@C
4929: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4930: `SNES` options in the database.
4932: Logically Collective
4934: Input Parameters:
4935: + snes - the `SNES` context
4936: - prefix - the prefix to prepend to all option names
4938: Level: advanced
4940: Note:
4941: A hyphen (-) must NOT be given at the beginning of the prefix name.
4942: The first character of all runtime options is AUTOMATICALLY the hyphen.
4944: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
4945: @*/
4946: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
4947: {
4948: PetscFunctionBegin;
4950: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
4951: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
4952: if (snes->linesearch) {
4953: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
4954: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
4955: }
4956: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
4957: PetscFunctionReturn(PETSC_SUCCESS);
4958: }
4960: /*@C
4961: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4962: `SNES` options in the database.
4964: Logically Collective
4966: Input Parameters:
4967: + snes - the `SNES` context
4968: - prefix - the prefix to prepend to all option names
4970: Level: advanced
4972: Note:
4973: A hyphen (-) must NOT be given at the beginning of the prefix name.
4974: The first character of all runtime options is AUTOMATICALLY the hyphen.
4976: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
4977: @*/
4978: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
4979: {
4980: PetscFunctionBegin;
4982: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
4983: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
4984: if (snes->linesearch) {
4985: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
4986: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
4987: }
4988: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
4989: PetscFunctionReturn(PETSC_SUCCESS);
4990: }
4992: /*@C
4993: SNESGetOptionsPrefix - Gets the prefix used for searching for all
4994: `SNES` options in the database.
4996: Not Collective
4998: Input Parameter:
4999: . snes - the `SNES` context
5001: Output Parameter:
5002: . prefix - pointer to the prefix string used
5004: Level: advanced
5006: Fortran Notes:
5007: The user should pass in a string 'prefix' of
5008: sufficient length to hold the prefix.
5010: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5011: @*/
5012: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5013: {
5014: PetscFunctionBegin;
5016: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5017: PetscFunctionReturn(PETSC_SUCCESS);
5018: }
5020: /*@C
5021: SNESRegister - Adds a method to the nonlinear solver package.
5023: Not Collective
5025: Input Parameters:
5026: + sname - name of a new user-defined solver
5027: - function - routine to create method context
5029: Level: advanced
5031: Note:
5032: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5034: Example Usage:
5035: .vb
5036: SNESRegister("my_solver", MySolverCreate);
5037: .ve
5039: Then, your solver can be chosen with the procedural interface via
5040: $ SNESSetType(snes, "my_solver")
5041: or at runtime via the option
5042: $ -snes_type my_solver
5044: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5045: @*/
5046: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5047: {
5048: PetscFunctionBegin;
5049: PetscCall(SNESInitializePackage());
5050: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5051: PetscFunctionReturn(PETSC_SUCCESS);
5052: }
5054: PetscErrorCode SNESTestLocalMin(SNES snes)
5055: {
5056: PetscInt N, i, j;
5057: Vec u, uh, fh;
5058: PetscScalar value;
5059: PetscReal norm;
5061: PetscFunctionBegin;
5062: PetscCall(SNESGetSolution(snes, &u));
5063: PetscCall(VecDuplicate(u, &uh));
5064: PetscCall(VecDuplicate(u, &fh));
5066: /* currently only works for sequential */
5067: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5068: PetscCall(VecGetSize(u, &N));
5069: for (i = 0; i < N; i++) {
5070: PetscCall(VecCopy(u, uh));
5071: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5072: for (j = -10; j < 11; j++) {
5073: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5074: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5075: PetscCall(SNESComputeFunction(snes, uh, fh));
5076: PetscCall(VecNorm(fh, NORM_2, &norm));
5077: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5078: value = -value;
5079: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5080: }
5081: }
5082: PetscCall(VecDestroy(&uh));
5083: PetscCall(VecDestroy(&fh));
5084: PetscFunctionReturn(PETSC_SUCCESS);
5085: }
5087: /*@
5088: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5089: computing relative tolerance for linear solvers within an inexact
5090: Newton method.
5092: Logically Collective
5094: Input Parameters:
5095: + snes - `SNES` context
5096: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5098: Options Database Keys:
5099: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5100: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5101: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5102: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5103: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5104: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5105: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5106: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5108: Level: advanced
5110: Note:
5111: The default is to use a constant relative tolerance for
5112: the inner linear solvers. Alternatively, one can use the
5113: Eisenstat-Walker method, where the relative convergence tolerance
5114: is reset at each Newton iteration according progress of the nonlinear
5115: solver.
5117: References:
5118: . - * S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5120: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5121: @*/
5122: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5123: {
5124: PetscFunctionBegin;
5127: snes->ksp_ewconv = flag;
5128: PetscFunctionReturn(PETSC_SUCCESS);
5129: }
5131: /*@
5132: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5133: for computing relative tolerance for linear solvers within an
5134: inexact Newton method.
5136: Not Collective
5138: Input Parameter:
5139: . snes - `SNES` context
5141: Output Parameter:
5142: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5144: Level: advanced
5146: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5147: @*/
5148: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5149: {
5150: PetscFunctionBegin;
5152: PetscAssertPointer(flag, 2);
5153: *flag = snes->ksp_ewconv;
5154: PetscFunctionReturn(PETSC_SUCCESS);
5155: }
5157: /*@
5158: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5159: convergence criteria for the linear solvers within an inexact
5160: Newton method.
5162: Logically Collective
5164: Input Parameters:
5165: + snes - `SNES` context
5166: . version - version 1, 2 (default is 2), 3 or 4
5167: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5168: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5169: . gamma - multiplicative factor for version 2 rtol computation
5170: (0 <= gamma2 <= 1)
5171: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5172: . alpha2 - power for safeguard
5173: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5175: Level: advanced
5177: Notes:
5178: Version 3 was contributed by Luis Chacon, June 2006.
5180: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5182: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5183: @*/
5184: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5185: {
5186: SNESKSPEW *kctx;
5188: PetscFunctionBegin;
5190: kctx = (SNESKSPEW *)snes->kspconvctx;
5191: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5200: if (version != PETSC_DEFAULT) kctx->version = version;
5201: if (rtol_0 != (PetscReal)PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5202: if (rtol_max != (PetscReal)PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5203: if (gamma != (PetscReal)PETSC_DEFAULT) kctx->gamma = gamma;
5204: if (alpha != (PetscReal)PETSC_DEFAULT) kctx->alpha = alpha;
5205: if (alpha2 != (PetscReal)PETSC_DEFAULT) kctx->alpha2 = alpha2;
5206: if (threshold != (PetscReal)PETSC_DEFAULT) kctx->threshold = threshold;
5208: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1 to 4 are supported: %" PetscInt_FMT, kctx->version);
5209: PetscCheck(kctx->rtol_0 >= 0.0 && kctx->rtol_0 < 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 <= rtol_0 < 1.0: %g", (double)kctx->rtol_0);
5210: PetscCheck(kctx->rtol_max >= 0.0 && kctx->rtol_max < 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 <= rtol_max (%g) < 1.0", (double)kctx->rtol_max);
5211: PetscCheck(kctx->gamma >= 0.0 && kctx->gamma <= 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 <= gamma (%g) <= 1.0", (double)kctx->gamma);
5212: PetscCheck(kctx->alpha > 1.0 && kctx->alpha <= 2.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "1.0 < alpha (%g) <= 2.0", (double)kctx->alpha);
5213: PetscCheck(kctx->threshold > 0.0 && kctx->threshold < 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 < threshold (%g) < 1.0", (double)kctx->threshold);
5214: PetscFunctionReturn(PETSC_SUCCESS);
5215: }
5217: /*@
5218: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5219: convergence criteria for the linear solvers within an inexact
5220: Newton method.
5222: Not Collective
5224: Input Parameter:
5225: . snes - `SNES` context
5227: Output Parameters:
5228: + version - version 1, 2 (default is 2), 3 or 4
5229: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5230: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5231: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5232: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5233: . alpha2 - power for safeguard
5234: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5236: Level: advanced
5238: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5239: @*/
5240: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5241: {
5242: SNESKSPEW *kctx;
5244: PetscFunctionBegin;
5246: kctx = (SNESKSPEW *)snes->kspconvctx;
5247: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5248: if (version) *version = kctx->version;
5249: if (rtol_0) *rtol_0 = kctx->rtol_0;
5250: if (rtol_max) *rtol_max = kctx->rtol_max;
5251: if (gamma) *gamma = kctx->gamma;
5252: if (alpha) *alpha = kctx->alpha;
5253: if (alpha2) *alpha2 = kctx->alpha2;
5254: if (threshold) *threshold = kctx->threshold;
5255: PetscFunctionReturn(PETSC_SUCCESS);
5256: }
5258: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5259: {
5260: SNES snes = (SNES)ctx;
5261: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5262: PetscReal rtol = PETSC_DEFAULT, stol;
5264: PetscFunctionBegin;
5265: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5266: if (!snes->iter) {
5267: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5268: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5269: } else {
5270: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5271: if (kctx->version == 1) {
5272: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5273: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5274: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5275: } else if (kctx->version == 2) {
5276: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5277: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5278: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5279: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5280: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5281: /* safeguard: avoid sharp decrease of rtol */
5282: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5283: stol = PetscMax(rtol, stol);
5284: rtol = PetscMin(kctx->rtol_0, stol);
5285: /* safeguard: avoid oversolving */
5286: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5287: stol = PetscMax(rtol, stol);
5288: rtol = PetscMin(kctx->rtol_0, stol);
5289: } else /* if (kctx->version == 4) */ {
5290: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5291: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5292: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5293: PetscReal rk = ared / pred;
5294: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5295: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5296: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5297: else rtol = kctx->v4_m2 * kctx->rtol_last;
5299: if (kctx->rtol_last_2 > kctx->v4_m3 && kctx->rtol_last > kctx->v4_m3 && kctx->rk_last_2 < kctx->v4_p1 && kctx->rk_last < kctx->v4_p1) rtol = kctx->v4_m4 * kctx->rtol_last;
5300: kctx->rtol_last_2 = kctx->rtol_last;
5301: kctx->rk_last_2 = kctx->rk_last;
5302: kctx->rk_last = rk;
5303: }
5304: }
5305: /* safeguard: avoid rtol greater than rtol_max */
5306: rtol = PetscMin(rtol, kctx->rtol_max);
5307: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5308: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5309: PetscFunctionReturn(PETSC_SUCCESS);
5310: }
5312: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5313: {
5314: SNES snes = (SNES)ctx;
5315: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5316: PCSide pcside;
5317: Vec lres;
5319: PetscFunctionBegin;
5320: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5321: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5322: kctx->norm_last = snes->norm;
5323: if (kctx->version == 1 || kctx->version == 4) {
5324: PC pc;
5325: PetscBool getRes;
5327: PetscCall(KSPGetPC(ksp, &pc));
5328: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5329: if (!getRes) {
5330: KSPNormType normtype;
5332: PetscCall(KSPGetNormType(ksp, &normtype));
5333: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5334: }
5335: PetscCall(KSPGetPCSide(ksp, &pcside));
5336: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5337: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5338: } else {
5339: /* KSP residual is preconditioned residual */
5340: /* compute true linear residual norm */
5341: Mat J;
5342: PetscCall(KSPGetOperators(ksp, &J, NULL));
5343: PetscCall(VecDuplicate(b, &lres));
5344: PetscCall(MatMult(J, x, lres));
5345: PetscCall(VecAYPX(lres, -1.0, b));
5346: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5347: PetscCall(VecDestroy(&lres));
5348: }
5349: }
5350: PetscFunctionReturn(PETSC_SUCCESS);
5351: }
5353: /*@
5354: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5356: Not Collective, but if snes is parallel, then ksp is parallel
5358: Input Parameter:
5359: . snes - the `SNES` context
5361: Output Parameter:
5362: . ksp - the `KSP` context
5364: Level: beginner
5366: Notes:
5367: The user can then directly manipulate the `KSP` context to set various
5368: options, etc. Likewise, the user can then extract and manipulate the
5369: `PC` contexts as well.
5371: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5373: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5374: @*/
5375: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5376: {
5377: PetscFunctionBegin;
5379: PetscAssertPointer(ksp, 2);
5381: if (!snes->ksp) {
5382: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5383: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5385: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5386: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5388: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5389: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5390: }
5391: *ksp = snes->ksp;
5392: PetscFunctionReturn(PETSC_SUCCESS);
5393: }
5395: #include <petsc/private/dmimpl.h>
5396: /*@
5397: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5399: Logically Collective
5401: Input Parameters:
5402: + snes - the nonlinear solver context
5403: - dm - the dm, cannot be `NULL`
5405: Level: intermediate
5407: Note:
5408: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5409: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5410: problems using the same function space.
5412: .seealso: [](ch_snes), `DM`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5413: @*/
5414: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5415: {
5416: KSP ksp;
5417: DMSNES sdm;
5419: PetscFunctionBegin;
5422: PetscCall(PetscObjectReference((PetscObject)dm));
5423: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5424: if (snes->dm->dmsnes && !dm->dmsnes) {
5425: PetscCall(DMCopyDMSNES(snes->dm, dm));
5426: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5427: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5428: }
5429: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5430: PetscCall(DMDestroy(&snes->dm));
5431: }
5432: snes->dm = dm;
5433: snes->dmAuto = PETSC_FALSE;
5435: PetscCall(SNESGetKSP(snes, &ksp));
5436: PetscCall(KSPSetDM(ksp, dm));
5437: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5438: if (snes->npc) {
5439: PetscCall(SNESSetDM(snes->npc, snes->dm));
5440: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5441: }
5442: PetscFunctionReturn(PETSC_SUCCESS);
5443: }
5445: /*@
5446: SNESGetDM - Gets the `DM` that may be used by some preconditioners
5448: Not Collective but dm obtained is parallel on snes
5450: Input Parameter:
5451: . snes - the preconditioner context
5453: Output Parameter:
5454: . dm - the dm
5456: Level: intermediate
5458: .seealso: [](ch_snes), `DM`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5459: @*/
5460: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5461: {
5462: PetscFunctionBegin;
5464: if (!snes->dm) {
5465: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5466: snes->dmAuto = PETSC_TRUE;
5467: }
5468: *dm = snes->dm;
5469: PetscFunctionReturn(PETSC_SUCCESS);
5470: }
5472: /*@
5473: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5475: Collective
5477: Input Parameters:
5478: + snes - iterative context obtained from `SNESCreate()`
5479: - npc - the preconditioner object
5481: Level: developer
5483: Notes:
5484: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5485: to configure it using the API).
5487: Only some `SNESType` can use a nonlinear preconditioner
5489: .seealso: [](ch_snes), `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5490: @*/
5491: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5492: {
5493: PetscFunctionBegin;
5496: PetscCheckSameComm(snes, 1, npc, 2);
5497: PetscCall(PetscObjectReference((PetscObject)npc));
5498: PetscCall(SNESDestroy(&snes->npc));
5499: snes->npc = npc;
5500: PetscFunctionReturn(PETSC_SUCCESS);
5501: }
5503: /*@
5504: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5506: Not Collective; but any changes to the obtained the npc object must be applied collectively
5508: Input Parameter:
5509: . snes - iterative context obtained from `SNESCreate()`
5511: Output Parameter:
5512: . pc - preconditioner context
5514: Options Database Key:
5515: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5517: Level: developer
5519: Notes:
5520: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5522: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5523: `SNES`
5525: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5526: @*/
5527: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5528: {
5529: const char *optionsprefix;
5531: PetscFunctionBegin;
5533: PetscAssertPointer(pc, 2);
5534: if (!snes->npc) {
5535: void *ctx;
5537: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5538: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5539: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5540: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5541: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5542: PetscCall(SNESGetApplicationContext(snes, &ctx));
5543: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5544: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5545: }
5546: *pc = snes->npc;
5547: PetscFunctionReturn(PETSC_SUCCESS);
5548: }
5550: /*@
5551: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5553: Not Collective
5555: Input Parameter:
5556: . snes - iterative context obtained from `SNESCreate()`
5558: Output Parameter:
5559: . has_npc - whether the `SNES` has an NPC or not
5561: Level: developer
5563: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5564: @*/
5565: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5566: {
5567: PetscFunctionBegin;
5569: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5570: PetscFunctionReturn(PETSC_SUCCESS);
5571: }
5573: /*@
5574: SNESSetNPCSide - Sets the preconditioning side.
5576: Logically Collective
5578: Input Parameter:
5579: . snes - iterative context obtained from `SNESCreate()`
5581: Output Parameter:
5582: . side - the preconditioning side, where side is one of
5583: .vb
5584: PC_LEFT - left preconditioning
5585: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5586: .ve
5588: Options Database Key:
5589: . -snes_npc_side <right,left> - nonlinear preconditioner side
5591: Level: intermediate
5593: Note:
5594: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5596: .seealso: [](ch_snes), `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`
5597: @*/
5598: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5599: {
5600: PetscFunctionBegin;
5603: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5604: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5605: snes->npcside = side;
5606: PetscFunctionReturn(PETSC_SUCCESS);
5607: }
5609: /*@
5610: SNESGetNPCSide - Gets the preconditioning side.
5612: Not Collective
5614: Input Parameter:
5615: . snes - iterative context obtained from `SNESCreate()`
5617: Output Parameter:
5618: . side - the preconditioning side, where side is one of
5619: .vb
5620: `PC_LEFT` - left preconditioning
5621: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5622: .ve
5624: Level: intermediate
5626: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`
5627: @*/
5628: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5629: {
5630: PetscFunctionBegin;
5632: PetscAssertPointer(side, 2);
5633: *side = snes->npcside;
5634: PetscFunctionReturn(PETSC_SUCCESS);
5635: }
5637: /*@
5638: SNESSetLineSearch - Sets the linesearch on the `SNES` instance.
5640: Collective
5642: Input Parameters:
5643: + snes - iterative context obtained from `SNESCreate()`
5644: - linesearch - the linesearch object
5646: Level: developer
5648: Note:
5649: Use `SNESGetLineSearch()` to retrieve the preconditioner context (for example,
5650: to configure it using the API).
5652: .seealso: [](ch_snes), `SNESGetLineSearch()`
5653: @*/
5654: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5655: {
5656: PetscFunctionBegin;
5659: PetscCheckSameComm(snes, 1, linesearch, 2);
5660: PetscCall(PetscObjectReference((PetscObject)linesearch));
5661: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5663: snes->linesearch = linesearch;
5665: PetscFunctionReturn(PETSC_SUCCESS);
5666: }
5668: /*@
5669: SNESGetLineSearch - Returns the line search context set with `SNESSetLineSearch()`
5670: or creates a default line search instance associated with the `SNES` and returns it.
5672: Not Collective
5674: Input Parameter:
5675: . snes - iterative context obtained from `SNESCreate()`
5677: Output Parameter:
5678: . linesearch - linesearch context
5680: Level: beginner
5682: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5683: @*/
5684: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5685: {
5686: const char *optionsprefix;
5688: PetscFunctionBegin;
5690: PetscAssertPointer(linesearch, 2);
5691: if (!snes->linesearch) {
5692: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5693: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5694: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5695: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5696: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5697: }
5698: *linesearch = snes->linesearch;
5699: PetscFunctionReturn(PETSC_SUCCESS);
5700: }