From: Mojca M. <moj...@gm...> - 2012-09-30 09:23:30
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On Sun, Sep 30, 2012 at 2:07 AM, Ethan Merritt wrote: > >> 6. Removing duplicate messages (such as duplicate consecutive V commands) sounds >> great. We should do it > OK. Low priority because it's relatively rare for normal plots. Not necessary, in particular when plotting "using 0:1" with a huge number of points (or almost any number bigger than screen resolution). Actually, it is what I do all the time. A dedicated program for drawing long signals that I'm using goes even a step further and does the following optimisation: - keep collecting all the points that would use the same pixel in x-direction - out of those points remember the minimum, maximum, first and last value of y. This only works for plots (1) with more or less sequential values of x (most plots?) and it only makes any difference (2) when the number of points is significantly bigger than width of the plot. I agree with Ethan that most plots don't meet the second criteria, but for plots that do, it makes an enormous difference (unless the bottleneck is reading the data from input). When drawing one million points on the screen with 1000 pixels this results in 2-4 points per 1000 values. That's perfectly consistent with Ethan's observation of 50-fold speed-up (and again, it is something that I do on a daily basis). I'll try to figure out how exactly you do the benchmarking of Dima's patches. I'm very curious about the effect on Mac OS X. (I really hated x11 terminal on Mac OS X, but now that I'm using those long traces and want to zoom in, AquaTerm still lacks mouse support and Qt has some serious efficiency problems, x11 is currently the only terminal left that does the job quickly and a lot more efficient than the rest.) Mojca |