matplotlib/matplotlib — pull request #660 by efiring (2012-01-06 17:24:33+00:00)
Title: Colormap alpha

Expands LinearSegmentedColormap and ListedColormap to support full RGBA. This was prompted by a mailing list thread: http://www.mail-archive.com/matplotlib-users@lists.sourceforge.net/msg22983.html, continued with: http://www.mail-archive.com/matplotlib-devel@lists.sourceforge.net/msg08808.html. It is close to a patch proposed by @ivanov a couple years ago. A changeset by @mdboom is included to fix a bug in images with alpha less than 1.