On 2009-07-31 11:49+0100 Alban Rochel wrote: [...]
> - QtWidget and ExtQt plot faster (1), especially when plotting x/y > rectangular filled shapes (2). Example x20c is now *much* faster. [...] > (1) - The buffer stores pointers to Qt plot primitives rather than the > data used to generate them at every plot (e.g QRect* rather than struct > holding x, y, width and height). I feared that this would consume more > memory, but this is barely noticeable if at all in the end. > - Colours are now only stored at colour changes, not associated to every > primitive any more > (2) - We used to use pens to draw the rectangles outlines, which is > wrong as it adds width, and makes drawing much slower > - Disabling of antialiasing for these primitives, as this could result > in thin "gaps" between tiles, producing Moire patterns I have recently been doing some interactive testing, and I have to comment on the outstanding speed obtained with the new version of qtwidget. Here are some timing comparisons for example 8, but other examples also show these type of qualitative results. softw...@raven> time c/x08c -dev xwin real 0m0.769s user 0m0.152s sys 0m0.072s softw...@raven> time c/x08c -dev qtwidget real 0m0.974s user 0m0.624s sys 0m0.016s softw...@raven> time c/x08c -dev xcairo real 0m3.031s user 0m1.232s sys 0m0.084s I held down the enter key to autorepeat as rapidly as possible through the various pages of the example in each case so I believe the "real" times are reliable even though in each case they are substantially larger than the sum of user + sys time (presumably because of different waits for system resources required by the three different methods used here for generating the results). Focussing just on the real times, the qtwidget speed is outstanding considering all the extra font rendering and antialiasing work it does to make nice looking results compared to -dev xwin in roughly the same amount of time. -dev xcairo has similar nice looking results as qtwidget, but it takes roughly three times longer to render the result. That's interesting, but I don't think that is a major xcairo concern since I believe developers should not optimize unless there is an order of magnitude or so to be gained, and that is clearly not the case here. I was curious about the speed of qtwidget in the old days and here is one result I posted to this list in late April. softw...@raven> time c/x08c -dev qtwidget real 0m5.423s user 0m3.432s sys 0m0.132s Obviously, there has been more than 5 times improvement in qtwidget speed since then. Thanks, Alban! Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
