On Mon, Jun 9, 2008 at 2:27 PM, David Harvey <[EMAIL PROTECTED]> wrote:
> > > On Jun 9, 2008, at 5:17 PM, Jonathan Bober wrote: > > > > > On Mon, 2008-06-09 at 10:19 -0700, mabshoff wrote: > >> > >> [...] > >> No clue. Can you actually compare the gp binary from Sage directly > >> with the timings from your self builid binary to eliminate the > >> problem > >> that libPari is involved here? If the gp binary in Sage is slower > >> by a > >> factor of three compared to the one you build this sounds like a bug > >> to me. But it could also be conversation overhead for example. > > > > Definitely could be conversion overhead. On my machine (warning: I'm > > still running the "ridiculously old" Sage 2.10.2) I get > > > > sage: time y = pari(40000).bernfrac() > > CPU times: user 4.14 s, sys: 0.00 s, total: 4.14 s > > Wall time: 4.15 > > sage: type(y) > > <type 'sage.libs.pari.gen.gen'> > > sage: time x = Rational(y) > > CPU times: user 1.50 s, sys: 0.00 s, total: 1.50 s > > Wall time: 1.50 > > > > It looks like the conversion from sage.lib.pari.gen.gen to > > sage.rings.rational.Rational just converts y to a string and then > > parses > > the resulting string, which is why this takes so long. > > That's true, that definitely accounts for part of it. Yep. But there's still quite a big gap between the times from sage -gp and > from my standalone GP build (see my followup email earlier on this > thread). > Yes. > > I wonder if we are just building GMP incorrectly. That bernfrac() > routine should depend mainly on the speed of long integer > multiplication and division. I am not a GP expert --- how does one > generate large random integers in GP? I could try multiplying them to > see how long that takes. > Well, I believe that out spkg-install for GMP is potentially broken since we updated to gmp 4.2.2. There are also some potential issues with pre-3.0.3 gmp.spkgs, so I am adding some explicite messages that lets you know that Jason's GMP patch was actually applied. > > david > Cheers, Michael > > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
