Phillip M. Feldman wrote: > Hello Eric- > > When I look at http://matplotlib.sourceforge.net/api/colors_api.html, > the documentation for LinearSegmentedColormap indicates that there is a > parameter called "N" but does not specify what this parameter does. > Thanks for clarifying this. I will submit a patch to the documentation. > > My main problem with ListedColormap is that the documentation for that > function does not specify whether the resulting colormap is discrete > (piecewise-constant) or continuous (piecewise-linear). I strongly > suspect that ListedColormap can only be used to generate discrete > colormaps, and I need both types.
Yes, ListedColormap is for discrete maps, and LinearSegmentedColormap is for piecewise-linear (to within the resolution provided by the size of the look-up table). There is a new staticmethod of the latter, from_list(), which simplifies the colormap generation for the very common case you are concerned with. It may be that its API needs some tweaking; it probably needs an example in the examples directory (if there isn't one; etc. I don't agree with your comment about the ListedColormap documentation; I think it is reasonably clear, if you read the whole docstring, and especially the description of N. Eric > > Phillip > > Eric Firing wrote: >> Dr. Phillip M. Feldman wrote: >>> The attached script creates a colormap containing five colors. At the >>> end of >>> the script, I print the value of cmap.N, and it is 256 rather than 5. >>> >>> http://www.nabble.com/file/p25740788/bugdemo.py bugdemo.py >> >> No, it is not a bug. You never told LinearSegmentedColormap that you >> wanted a map with other than 256 colors, which is the default. If you >> want a colormap with 3 colors, use a ListedColormap. In fact, as I >> wrote before, this, together with a BoundaryNorm, is the best way to >> handle the mapping of discrete colors. >> >> 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
