On Thursday 21 August 2008, Bill Hart wrote: > Hi William, > > At the start of your talk in the pdf, the irc chat seems to have the > lines cut off. > > Also at the end of the pdf you mention that SAGE will use the new > russian library ginv for poly gcd and factorisation. I didn't seem to > be able to find functions in the user's guide in the tarball for the > latest version which mentioned poly gcd or factorisation, though I may > have missed them. I also had a look through the source code and > couldn't find them either, though again I didn't look all that > thoroughly.
Ginv isn't exactly new, afaik. Also the MGCD isn't exported to the user but only used internally. Burcin tested it and seemed pleased. It certainly isn't vaporware. I can't tell how fast it actually is, i.e. whether it is really the world's fastest. On the other hand, there aren't that many implementations around. > But did you mean Groebner bases? There is code there for doing Janet > reduction, whatever that is. And it seems to compare favourably with > Magma according to benchmarks on Arxiv. "The open source software GINV implements the Gröbner bases method for systems of equations. GINV is a C++ module of Python designed for constructing Gröbner bases of ideals and modules in polynomial, differential and difference rings. Gröbner bases are constructed by involutive algorithms." ( http://invo.jinr.ru/ginv/users_guide_en/introduction.ginv.html ) Janet bases are involutive bases which incidentally are also redundant Gröbner bases. What benchmarks are you referring to? I heard several times that Ginv compares favourably to Magma over QQ for some examples, but couldn't reproduce anything so far. Also, Ginv is supposed to compute GBs over ZZ, but I couldn't get that to work either so far. Burcin might have had more luck. For anyone who wants to try it out, a SPKG is available at: http://sage.math.washington.edu/home/malb/spkgs/ginv-1.9-20080723.spkg and a crude interface here: http://sage.math.washington.edu/home/malb/py/basis_via_ginv.py Cheers, Martin -- name: Martin Albrecht _pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 _www: http://www.informatik.uni-bremen.de/~malb _jab: [EMAIL PROTECTED] --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
