I think the first computation of 10 seconds makes sense. You are basically doing around 30 definite integrals symbolically, multiplying each by a sine or cosine, adding them and plotting the result. If Maxima is doing something "dumb", I guess it depends on how you define the term. I'm *guessing* that it is the Maxima evaluation of the trig sum to create the plot which is the bottleneck here. This is a finite trig sum (and will always be a finite trig sum for any use of this method) which is known to Python I, so Maxima is not needed for the evaluation.
I vaguely remember emails about speeding up maxima evaluations using some other method (fast_float or something like that?), but I don't remember details. So, it might be dumb to use Maxima but I don't know how to make Sage just use Python for the evaluations. On Sat, Dec 6, 2008 at 12:51 AM, mabshoff <[EMAIL PROTECTED]> wrote: > > This *sucks*: > > ---------------------------------------------------------------------- > | Sage Version 3.2.2.alpha0, Release Date: 2008-12-05 | > | Type notebook() for the GUI, and license() for information. | > ---------------------------------------------------------------------- > sage: f1(x) = -1 > sage: f2(x) = 2 > sage: f = Piecewise([[(-pi,-pi/2),f1],[(-pi/2,0),f2],[(0,pi/2),f1], > [(pi/2,pi),f2]]) > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 2.01 s, sys: 0.79 s, total: 2.80 s > Wall time: 10.23 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 1.88 s, sys: 1.01 s, total: 2.89 s > Wall time: 13.01 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 1.96 s, sys: 0.98 s, total: 2.94 s > Wall time: 17.18 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 2.06 s, sys: 0.88 s, total: 2.94 s > Wall time: 20.83 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 2.03 s, sys: 0.98 s, total: 3.01 s > Wall time: 24.82 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 2.06 s, sys: 0.97 s, total: 3.03 s > Wall time: 27.56 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 2.31 s, sys: 1.06 s, total: 3.38 s > Wall time: 30.36 s > sage: time P = f.plot_fourier_series_partial_sum_filtered(15,pi,[1] > *15,-5,5) > CPU times: user 2.32 s, sys: 0.86 s, total: 3.18 s > Wall time: 33.04 s > sage: > > I discovered the above while poking around whether we had a > performance regression due to "#4693: Mike Hansen: cleanup work in > sage/functions/piecewise.py". The good new is that there isn't any, in > most cases the new code is faster while in some cases it is slightly > slower. But every time I rerun any of the plotting tests that are > marked "#long time" the time goes up and it is not spend in Sage, but > in Maxima. > > So: Am I doing something dumb? Are we telling Maxima to do dumb > things? Or is this a problem with Maxima? I don't have the time to > poke around here in the next couple days, so if anybody wants to > investigate I am more than happy to find out what is wrong here. > > 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 -~----------~----~----~----~------~----~------~--~---
