I should have some time today to look at this, unless any other developers already know an obvious solution.
Cheers, Mike Darren Dale wrote: > I have been working on an application which is basically a dressed up version > of embedding_in_qt4.py. I have two canvases, one is just a plot, the other an > image with a colorbar, both of which should get updated about once a second > as data is acquired. I noticed that for larger images, it was taking longer > to update the canvases as time went on. > > Attached is a script that demonstrates the problem (png's are also attached > for those who dont have PyQt4). At each timeout, I check the time, generate a > new random array, update the image's data, draw it, collect garbage, and > check the time again. The plot in the upper window shows how long it took to > update the image canvas as a function of iteration number. > > When the image has a colorbar, the time to update the image canvas increases > linearly, about 0.3 ms/iteration. This can really add up: after 20,000 > iterations it takes about 5-6 seconds to update the image canvas. If I > comment out the line that creates the colorbar (line 64), the time to update > the image canvas does not increase. > > A couple other observations and benchmarks from this test: > > * The intercept for the update time with a color bar was 0.17 seconds > * With the colorbar enabled but garbage collection turned off, the > application > slowly consumed memory, roughly 12KB/iteration > * Updating an image without a colorbar took 0.1 seconds per iteration, and > did > not increase > * Turning off both garbage collection and the colorbar decreased the update > time to 0.043 seconds, with maybe 1.7 KB/iteration increase in memory usage. > > I don't know if I'll get a chance to dig any further into this in the next > two > weeks. For now, I'll just disable the colorbar in my application. > > Darren > > > ------------------------------------------------------------------------ > > > ------------------------------------------------------------------------ > > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > > ------------------------------------------------------------------------ > > _______________________________________________ > Matplotlib-devel mailing list > Matplotlib-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
