There is code for up to 64 variables. I'm not sure for more. Can you send your input? That way I can check with gdb.
On Monday, June 5, 2023 at 9:19:04 PM UTC+2 Brent W. Baccala wrote: > Hi - > > I don't think giac can handle more than 15 variables in a Gröbner basis > calculation. > > This limitation isn't really documented anywhere, but if you look in > giac's src/cocoa.cc around lines 490-500, function swap_indices and think > about it a few minutes, you'll see that it can't handle more than 15 > variables, I think. I'm looking at giac 1.9.0. > > I tried a calculation on a ring with 67 variables and the algorithm went > into an infinite loop because it couldn't compare monomial exponents > properly. It produced a polynomial with two terms, both with the same > monomial (different coefficients), and that triggered the infinite loop in > the reduction code. > > I hope somebody working with this code will check my work and verify that > giac is so limited. If so, we should add a check to the groebner_basis > routine in src/sage/libs/giac/__init__.py > > agape > brent > > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/3ec9d87b-0692-4bc7-87ec-c0b2ae11420an%40googlegroups.com.
