Ryan May wrote: > Eric Firing wrote: > >> Ryan, >> >> The pcolor implementation is fundamentally unsuited to large arrays. >> Therefore I made the pcolorfast axes method, which tries to use the >> fastest available Agg extension code, depending on the characteristics >> of the spatial grid. If the grid is rectangular and regular in both >> directions it uses a slight modification of the image code; if it is >> rectangular but with irregular spacing, it uses the nonuniform image >> code; and if it is not rectangular it uses the quadmesh code. It sounds >> like what you need is the quadmesh version, which you can access either >> via pcolormesh or pcolorfast. Neither is exposed via the pylab or >> pyplot API at present; both are axes methods. The pcolorfast API also >> may change slightly in the future; it probably needs a little more work. >> > > Yeah, I think for purposes of plotting radar data, quadmesh is what i need. > > >> The quadmesh code has problems with masked arrays in the released >> version of mpl, but not in the svn version. It is *much* faster than >> pcolor, but may not be fast enough for your needs. >> > > My latest testing with the trunk with both pcolorfast and pcolormesh > would seem to indicate that it's still a bit too slow for me. > > >> If you are looking into what sounds like an OpenGL backend, or component >> to a backend, then the place to start is still probably pcolormesh or >> pcolorfast, not pcolor. >> > This is the approach I'm considering. I've been poking around, and > managed to create something that rendered, but not too well. However > this was basically modifying the Gtk backend, and I'm sure there are > some Gtk things that could be replaced. I noticed there are some other > draw_* methods in other backends that aren't in the gtk, like > draw_quad_mesh and draw_rectangle. Is there a definitive list > somewhere? I tried RendererBase in backend_bases, but it did not have > draw_rectangle. The pure Gtk backend has no optimizations for draw_quad_mesh. You may find that the Agg (e.g. GtkAgg) backend is significantly faster with quad meshes because it uses optimized C++ code to draw the mesh. The Gtk version must make (as you discovered) a Python function call for each quadrilateral.
The definitive list of methods on rendering backends is in backend_bases.py. There are "required" methods, and methods that may be provided for optimization reasons (the latter are the ones that mention having a "fallback" implementation in RendererBase). Hope that helps, Mike ------------------------------------------------------------------------- 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-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
