On Mon, Nov 10, 2014 at 3:08 PM, Ursula Whitcher <whitc...@uwec.edu> wrote: > On 11/5/2014 8:24 AM, William Stein wrote: > >> * By "we write up" above, I mean you write up something very, very >> rough, post it here, and get feedback. > > > Done! > > http://people.uwec.edu/whitchua/notes/sagebugprocess.pdf
Wow, that's really nice! I really like the tone and length. > I stuck with Ticket 14032 as my example; I think the tradeoff of interesting > algorithm vs. boring bug is OK for a general math audience. > > Questions: > > * Who found the bug corresponding to ticket 14032? Was the computation in > service of an interesting research question? > Jeroen Demeyer reported it -- did you also *find* it Jeroen? > * Originally, William said "working modulo a few additional primes". Does > this mean doing p-adic lifting again, or just black-box computing det A (mod > p), as I have implied? Just black-box computing det A, as you implied. One thing that isn't technically 100% correct about the p-adic lifting part of what you say is that one in fact works modulo several distinct primes lifting p-adically a bit, rather than modulo only one prime. You might just say in parens that the actual implementation is slightly more subtle than what you describe and cite https://cs.uwaterloo.ca/~astorjoh/iml.html I've cc'd Arne Storjohann (co-author of IML) and Clement Pernet on this message. As Sage is switching to FLINT very soon by default for integer matrix determinants (due to Marc Masdue's recent patch), I wonder what algorithm FLINT uses for this problem? It would be good to be aware at least. > * How fast is the p-adic algorithm? William said it was faster than > Mathematica; does someone have some graphs? It depends enormously on many other factors, how things are compiled, etc... For big integer coefficients, the main bottleneck is IML. Perhaps Storjohann can make a remark about the theoretical complexity and provide a reference. > * Is Jeroen Demeyer still a postdoc? Where was Volker at the time of our > story? > > --Ursula. > > > -- > 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 post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- William Stein Professor of Mathematics University of Washington http://wstein.org -- 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 post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
