Dr. Phillip M. Feldman wrote: > After experimenting with colormaps for a while, I was able to make both > discrete (piecewise-constant) and continuous (piecewise-linear) colormaps > work. Although colormaps can be created directly using > LinearSegmentedColormap from the matplotlib.colors package, this is a > tedious and error-prone process. So, I compiled a set of three interface > functions. (I wrote two of these myself, and got one from the SciPy > website). The two functions that I wrote permit one to define a discrete > (piecewise-constant) and continuous (piecewise-linear) colormap directly via > a sequence of colors and a set of thresholds specified as lists. Each color > may be specified either via an RGB tuple or via an English color name known > to webcolors.name_to_rgb. I'm going to submit all of this to the matplotlib > developers forums in the hopes of getting it incorporated into matplotlib.
Something I should have mentioned earlier: for the discrete case, one good option is to use a ListedColormap to make a map with only a few colors, and then use a BoundaryNorm to handle the mapping from data values to colors. See http://matplotlib.sourceforge.net/examples/pylab_examples/image_masked.html?highlight=image_masked for a BoundaryNorm example. Unfortunately, we don't have an example of using it with a ListedColormap, but it should be straigtforward; the key point is to set the BoundaryNorm ncolors kwarg to match the actual number of colors in the colormap. Eric ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
