I wonder if it is possible to recreate the problem just using FLINT, without any Sage, i.e. just write a short FLINT program which replicates the problem.
I don't understand how the multiplication could take any serious quantity of time unless the pow was screwed up somehow. But perhaps it is. Could you insert some traces to print the values of m, the number of limbs of lead and (when it is computed) the number of limbs of t. Bill. On Jan 29, 2:10 am, Sebastian Pancratz <s...@pancratz.org> wrote: > On Jan 29, 12:54 am, Bill Hart <goodwillh...@googlemail.com> wrote: > > > One possibility is that the problem occurs only on 32 bit machines or > > only 64 bit machines and not the other kind. Have you got access to > > both 32 and 64 bit architectures to try this on? > > Running the commands on a similar set up (Sage 4.3.1.rc0, with the > patches from #383 and #4000) on a 64-bit machine at the department > just now gave the following: > > sage: R.<x> = QQ[] > sage: f = 3/2*x - 1/3 > sage: %time _ = f % f > CPU times: user 5.18 s, sys: 0.42 s, total: 5.60 s > Wall time: 5.60 s > > So the problem can also appear on 64-bit machines. Moreover, I > noticed that the run time can vary between Sage sessions. Restarting > Sage, I found this: > > sage: R.<x> = QQ[] > sage: f = 3/2*x - 1/3 > sage: %time _ = f % f > CPU times: user 0.93 s, sys: 0.13 s, total: 1.06 s > Wall time: 1.06 s > > Of course, this now taking 1s still means something is very wrong, but > perhaps this variability can help locate the error? Interestingly, > after trying this a couple of times, the above two timings (around > 5.6s and around 1.1s) seem to be the only ones that come up. They can > also come up in the same Sage session by re-creating the polynomial: > > sage: R.<x> = QQ[] > sage: f = 3/2*x - 1/3 > sage: %time _ = f % f > CPU times: user 0.93 s, sys: 0.13 s, total: 1.06 s > Wall time: 1.06 s > sage: %time _ = f % f > CPU times: user 0.94 s, sys: 0.10 s, total: 1.04 s > Wall time: 1.04 s > sage: R.<x> = QQ[] > sage: f = 3/2*x - 1/3 > sage: %time _ = f % f > CPU times: user 5.10 s, sys: 0.43 s, total: 5.53 s > Wall time: 5.53 s > > Kind regards, > > Sebastian -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
