On Jan 15, 2008 7:46 AM, Michael Droettboom <[EMAIL PROTECTED]> wrote: > Ah -- just thought of something else. > > If I adjust simple_plot_fps.py to have 100,000 data points rather than > 1,000 I see something that starts to match with what you're seeing: > > GtkAgg: > wallclock: 4.23297405243 > user: 3.33 > fps: 23.6240522057 > > Gtk: > wallclock: 15.0203828812 > user: 14.92 > fps: 6.65761990165 > > TkAgg: > wallclock: 4.8252530098 > user: 4.67 > fps: 20.7243018754 > > You can see that the Gtk time is starting to explode. If I go to > 1,000,000 points, Gtk runs out of memory before the first plot, whereas > the other two continue to chug along at a reasonable pace. > > From looking at the code, I suspect the crucial difference is that the > Gdk backend uses the Python sequence API (rather slow) to access the > data as it gets rendered, whereas GtkAgg uses the numpy array interface > which is essentially raw access to a C array.
This is not likely to be the culprit -- for drawing markers, the old matplotlib API made a separate call to draw_polygon for every marker, with a new gc each time. Many moons ago, we implemented draw_markers as a renderer method to avoid this problem. For hundreds of thousands of markers, we saw performance benefits of 25x to 100x. The backends which implement draw_markers (Agg and PS) get the benefits, but the other backends which did not are still slow. Basically it is a problem with a lot of redundant function call overhead. The backend_bases renderer method _draw_markers discusses this a little bit (it is underscore hidden). My guess is this difference will not be so pronounced on the trunk. JDH ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
