Interface to Groebner Fan#
Anders Nedergaard Jensen: Write gfan C++ program, which implements algorithms many of which were invented by Jensen, Komei Fukuda, and Rekha Thomas.
William Stein (2006-03-18): wrote gfan interface (first version)
Marshall Hampton (2008-03-17): modified to use gfan-0.3, subprocess instead of os.popen2
TODO – much functionality of gfan-0.3 is still not exposed:
* at most 52 variables: - use gfan_substitute to make easier (?) MH: I think this is now irrelevant since gfan can accept the original ring variables * --symmetry is really useful - permutations are 0-based *not* cycle notation; a <---> 0 output is broken up much more nicely. * -- can work in Z/pZ for p <= 32749 * -- can compute individual GB's for lex and revlex (via buchberger)
- class sage.interfaces.gfan.Gfan#
Interface to Anders Jensen’s Groebner Fan program.