SparsePolyOps-SturmSeq

© 2017 John Abbott, Anna M. Bigatti

GNU Free Documentation License, Version 1.2

CoCoALib Documentation Index

Examples

User documentation

This file offers two functions: SturmSeq and NumRealRoots.

Operations

Let f be a RingElem whose value is a univariate polynomial with rational coefficients.

  • SturmSeq(f) -- returns a vector<RingElem> being the Sturm sequence of the polynomial f (in order of decreasing degree)
  • NumRealRoots(f) -- returns a long` being the number of real roots ``f has.

Maintainer documentation

The implementation is naive and simple; this is OK for small examples. Currently it computes a primitive PRS; seems adequate for smallish tests.

Bugs, shortcomings and other ideas

Clears denominators, but I'm not sure why content works.

Main changes

2017

  • November (v0.99561): first release