On Mon, Nov 17, 2008 at 3:24 PM, Martin Mereb <[EMAIL PROTECTED]> wrote: > > I see I expressed myself wrong > (I meant the problem was in the "for" line) > so what's going on is that gap is attempting to built first the whole > list and that is taking way too much time (right?) > are there any iterator that avoids that amount of memory and take the > elements "on the fly", like xrange? > Because I don't wanna print all of the matrices, I just wanted to > iterate among them and compute one counterexample and then break the > loop, and I just found out the problem was when the iteration begins.
GAP's Filtered command is relatively fast at doing that. http://www.gap-system.org/Manuals/doc/htm/ref/CHAP021.htm#SSEC020.18 > > On Mon, Nov 17, 2008 at 12:31 PM, Justin C. Walker <[EMAIL PROTECTED]> wrote: >> >> >> On Nov 17, 2008, at 9:34 AM, Martin Mereb wrote: >> >>> >>> I'm trying to run the following: >>> >>> sage: n=3; q=7; G=SL(n,q) >>> sage: for a in G: >>> ....: print a >>> ....: >>> >>> it just got stuck there, nothing shows up (for a looong while) >>> this is Sage version 3.1.1 >>> >>> and if I try the same with q=4 it works (but it takes some time to >>> start) >>> any ideas? >> >> There's a Gap in your thinking. Or, at least, in your processing :-} >> >> In this case (SL(n,q)), we ask Gap to produce the results. In both >> cases (q=4,7), Gap is working pretty hard to come up with the >> elements in the group (it does have 5.6 million elements, for q=7; >> for q=4, it's ~60K). In any case, the time is being spent in Gap, >> and it has nothing to do with 'for'. >> >> If you start Gap (e.g., "sage -gap" in a shell window), and compute >> either Elements(SL(3,7)) or AsList(SL(3,7)) (the latter presumably >> being faster, but I didn't have the patience to wait :-}), you will >> see what I mean. >> >> HTH >> >> Justin >> >> -- >> Justin C. Walker, Curmudgeon-At-Large >> Institute for the Absorption of Federal Funds >> -------- >> Men are from Earth. >> Women are from Earth. >> Deal with it. >> -------- >> >> >> >> >> > >> > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@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-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
