On Fri, Oct 2, 2009 at 9:30 PM, rjf <fate...@gmail.com> wrote: > > hey, factoring-testing guys.. > If you make up factoring problems this way, you are probably not doing > much testing of the real factoring algorithms. Repeated factors like
I for one am very grateful for this bug report. Andy is doing a superb job. William > this of different degree are detected by so-called square-free > factorization. > The time to factor F in Maxima is, to the resolution of the clock, > 0.0000 seconds on > a 3GHz Intel machine. > > F can also be entirely factored by the sqfr program, which uses a 5 > line program involving > differentiation, GCD, and division. So the problem is essentially no > harder than factoring f and g separately. > > There are papers that show how to construct polynomials that are > difficult to factor. > > I dunno about the Sage wrapper problem. If that's the difficulty, > maybe the subject line is wrong. > RJF > > > > > On Oct 1, 1:21 am, Andy Novocin <a...@novocin.com> wrote: >> By the way, last October I made a patch for NTL which makes NTL's >> factoring significantly faster than even MAGMA's in some cases. I >> think that the degree flags < 30 and > 300 for NTL's factoring >> (provided my patch went in) needs to be revisited anyway. >> >> On Oct 1, 8:37 am, Robert Bradshaw <rober...@math.washington.edu> >> wrote: >> >> > On Sep 30, 2009, at 8:25 PM, William Stein wrote: >> >> > > On Wed, Sep 30, 2009 at 7:13 PM, Marshall Hampton >> > > <hampto...@gmail.com> wrote: >> >> > >> Wow, that's quite disturbing. Did you make a trac ticket for this? >> >> > > I've made this: >> >> > >http://trac.sagemath.org/sage_trac/ticket/7088 >> >> > > and made it a 4.1.2 blocker, since it a serious bug. The problem is >> > > in the _factor_pari method in Sage. It's almost certainly a bug in >> > > Sage's wrapper of Pari for factoring in the non-monic case. The >> > > solution will be either to fix that (good) or use the ntl wrapper >> > > (wimpy). >> >> > Wow, it looks like this bug has been around since the very first >> > checkin. I posted a patch. >> >> > - Robert >> >> > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
