Please make sure to keep in some of the tricks I put in, such as only counting points over the subfield generated by the j-invariant of the curve. Does the pari code do that? I hope so.
John On 15 September 2014 18:06, William A Stein <[email protected]> wrote: > On Mon, Sep 15, 2014 at 9:19 AM, Jeroen Demeyer <[email protected]> > wrote: >> On 2014-09-15 17:33, William A Stein wrote: >>>> >>>> I see three possible options (in decreasing order of preference for me): >>>> (1) Upgrade PARI to latest master instead of a stable version. >>>> (2) Backport the Kedlaya implementation to PARI-2.7.x and put that in >>>> Sage. >>>> (3) Keep the current slow Sage algorithm for point counting over F_q in >>>> the >>>> cases where PARI SEA doesn't work. >>> >>> >>> (3) clearly seems the safest assuming it is obvious what the cutoff is. >> >> If you say that (3) is the safest, you assume that Sage code is more >> reliable than PARI code. I wouldn't want to bet on that :-) >> The cutoff is not obvious but a try/except would easily work. > > I know this specific code, since I've read it, Cremona wrote it, and > it's pretty mature. Sage overall, not so clear. > >>> (1) is very hard to evaluate -- will it cause all kinds of extra >>> headaches or be easy? This depends immensely on the state of pari >>> development. >> >> At least there is a precedent: in Sage we have used an unstable branch of >> PARI for a long time before PARI-2.5.x came out and all went fine. >> Upgrading PARI always gives "extra headaches", even from one stable to >> another stable version (look at the patch for #15767). One could argue that >> by tracking PARI master more closely, we spread out the one big headache >> into smaller, more gradual headaches... > > Sure -- it's just more work. I strongly encourage you to do it, if > you're interested :-) > >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sage-nt" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send an email to [email protected]. >> Visit this group at http://groups.google.com/group/sage-nt. >> For more options, visit https://groups.google.com/d/optout. > > > > -- > William Stein > Professor of Mathematics > University of Washington > http://wstein.org > [email protected] > > -- > You received this message because you are subscribed to the Google Groups > "sage-nt" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send an email to [email protected]. > Visit this group at http://groups.google.com/group/sage-nt. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-nt" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. Visit this group at http://groups.google.com/group/sage-nt. For more options, visit https://groups.google.com/d/optout.
