Just to confirm in FriCAS the 'totalGroebner' routine which apparently uses degree reverse lexical ordering takes much less time:
Time: 1718.35 (EV) + 0.53 (OT) = 1718.88 sec and finds a basis with 28 polynomials (although that is still a lot longer than Singular needs for this computation). But as you say, even with this result I am a bit stuck since there I could not find any convenient way to change the ordering of a given basis. In computing 'groebnerFactorize' is there some way to keep the basis in degree reverse lexical order? Maybe it I use some other polynomial type rather than 'Polynomial'? On 15 May 2017 at 18:21, Ralf Hemmecke <[email protected]> wrote: > On 05/15/2017 07:30 PM, Bill Page wrote: >> I think the factor of 1000 in the difference in the time required to >> compute the Groebner basis suggests that Singular is probably >> using a different algorithm to produce this result - maybe >> something like choosing a more favorable term order and then >> walking the solution, but my first attempts to do this have not >> been able to improve on the timing. > > From the number of polynomials you get as a GB (28 vs. 34), > I guess, Sage and FriCAS use different target term orders. > > If that is the case, then I don't think that 10 sec vs several hours > is a big surprise. > > Nevertheless, FriCAS does not employ a very sophisticated > GB-algorithm. It's the plain Buchberger algorithm + criteria and > sugar strategy. > > We have no F4, GroebnerWalk or SlimGB or ... > Do you have any opinions about how hard in principle it might be to code these algorithms in FriCAS? Can one find good reference implementations somewhere that might be transcribed to SPAD? -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
