Hi, On Sat, 21 Nov 2009 14:02:16 +0100 Burcin Erocal <bur...@erocal.org> wrote:
> I can't believe I'm looking at these hashes for the third time. I > finally took some time to think about this, and found an (almost) > perfect hash function to replace my previous braindead implementation. > I hope we won't run into this problem again. :) > > This is now #7508: > > http://trac.sagemath.org/sage_trac/ticket/7508 There is a new pynac package linked from that ticket. You need to apply the patch from #7490 before you can run Sage with it. The new hash function doesn't have any collisions for a symbolic function with 10 arguments, up to derivatives of order 11. I used a customized FNV hash [1], with a prime multiplier chosen to accommodate the low integer values we get for each entry of the parameter set. [1] http://isthe.com/chongo/tech/comp/fnv/ Cheers, Burcin -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
