Charles Parker writes: > Hello plplot community :^) > > I have two questions w/ regards to the functionality of the plplot C++ > bindings. > > First, is it possible to plot single pixels in scatter plot (plpoin)? I've > tried using a lot of the different symbols and changing the size of those > symbols (with plssym), but I can't seem to find a combination that will just > turn on a single pixel for each data point I plot.
There is a trick that works fine for the xwin driver. But the "points" vanish for e.g. the ps driver, so YMMV. From plysm.c -- /*--------------------------------------------------------------------------*\ * void plpoin() * * Plots array y against x for n points using ASCII code "code". * * code=-1 means try to just draw a point. Right now it's just a move and * a draw at the same place. Not ideal, since a sufficiently intelligent * output device may optimize it away, or there may be faster ways of * doing it. This is OK for now, though, and offers a 4X speedup over * drawing a Hershey font "point" (which is actually diamond shaped and * therefore takes 4 strokes to draw). \*--------------------------------------------------------------------------*/ void c_plpoin(PLINT n, PLFLT *x, PLFLT *y, PLINT code) > Second, I'm going to be plotting about 5000 data points or so, the problem > is that the way my data are structured, the points I need to plot are not > stored sequentially in memory. I have data with about 15 parameters per > point, and I only want to plot points (the x and y are two of the > parameters) that satisfy some filtering criteria. Am I better off simply > taking the memory and performance hit to create an additional data structure > in which these data are sequential? Or can I simply call plpoin to plot each > individual point? In the latter case I would loop through the data only once > and plot points as I found them, whereas in the former there is the extra > overhead of creating the data structure and copying the data before I can > plot it. Calling plpoin for each point separately should be fine. -- Maurice LeBrun ------------------------------------------------------------------------- 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/ _______________________________________________ Plplot-general mailing list Plplot-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-general
