Merge pull request matplotlib#2871 from chebee7i/cbsafe_heatmap

Add a colorblind friendly heatmap.

Author: efiring

CHANGELOG

@@ -1,26 +1,24 @@
+2014-05-02 Added colorblind-friendly colormap, named 'Wistia'.
+
 2014-04-27 Improved input clean up in Axes.{h|v}lines
-	   Coerce input into a 1D ndarrays (after dealing with units).
+           Coerce input into a 1D ndarrays (after dealing with units).
 
 2014-04-22 Added an example showing the difference between
-	   interpolation = 'none' and interpolation = 'nearest' in
-	   `imshow()` when saving vector graphics files.
+           interpolation = 'none' and interpolation = 'nearest' in
+           `imshow()` when saving vector graphics files.
 
 2014-04-10 Fixed the triangular marker rendering error. The "Up" triangle was
            rendered instead of "Right" triangle and vice-versa.
 
 2014-04-08 Fixed a bug in parasite_axes.py by making a list out
            of a generator at line 263.
 
-2014-02-25 In backend_qt4agg changed from using update -> repaint under
-	   windows.  See comment in source near `self._priv_update` for
-	   longer explaination.
-
 2014-03-27 Added tests for pie ccw parameter. Removed pdf and svg images
            from tests for pie linewidth parameter.
 
 2014-03-24 Added bool kwarg (manage_xticks) to boxplot to enable/disable
-	   the managemnet of the xlimits and ticks when making a boxplot.
-	   Default in True which maintains current behavior by default.
+           the managemnet of the xlimits and ticks when making a boxplot.
+           Default in True which maintains current behavior by default.
 
 2014-03-22 Added the keyword arguments wedgeprops and textprops to pie.
            Users can control the wedge and text properties of the pie
@@ -32,9 +30,13 @@
 
 2014-03-13 Add parameter 'clockwise' to function pie, True by default.
 
-2014-27-02  Implemented separate horizontal/vertical axes padding to the
+2014-02-27 Implemented separate horizontal/vertical axes padding to the
            ImageGrid in the AxesGrid toolkit
 
+2014-02-25 In backend_qt4agg changed from using update -> repaint under
+           windows.  See comment in source near `self._priv_update` for
+           longer explaination.
+
 2014-01-02 `triplot` now returns the artist it adds and support of line and
            marker kwargs has been improved. GBY
 
@@ -53,7 +55,7 @@
            matplotlib.delaunay module. - IMT
 
 2013-11-05 Add power-law normalization method. This is useful for,
-	   e.g., showing small populations in a "hist2d" histogram.
+           e.g., showing small populations in a "hist2d" histogram.
 
 2013-10-27 Added get_rlabel_position and set_rlabel_position methods to
            PolarAxes to control angular position of radial tick labels.

doc/users/whats_new.rst

@@ -23,6 +23,17 @@ revision, see the :ref:`github-stats`.
 new in matplotlib-1.4
 =====================
 
+
+New colormap
+------------
+In heatmaps, a green-to-red spectrum is often used to indicate intensity of
+activity, but this can be problematic for the red/green colorblind. A new,
+colorblind-friendly colormap is now available at :class:`matplotlib.cm.Wistia`.
+This colormap maintains the red/green symbolism while achieving deuteranopic
+legibility through brightness variations. See
+`here <https://github.com/wistia/heatmap-palette>`
+for more information.
+
 Documentation changes
 ---------------------
 

lib/matplotlib/_cm.py

@@ -7,6 +7,7 @@
 
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
+
 import numpy as np
 
 _binary_data = {
@@ -1888,6 +1889,36 @@ def gfunc32(x):
                            (0.875, 0.50, 0.50),
                            (1.000, 1.00, 1.00))}
 
+
+# An MIT licensed, colorblind-friendly heatmap from Wistia:
+#   https://github.com/wistia/heatmap-palette
+#   http://wistia.com/blog/heatmaps-for-colorblindness
+#
+# >>> import matplotlib.colors as c
+# >>> colors = ["#e4ff7a", "#ffe81a", "#ffbd00", "#ffa000", "#fc7f00"]
+# >>> cm = c.LinearSegmentedColormap.from_list('wistia', colors)
+# >>> _wistia_data = cm._segmentdata
+# >>> del _wistia_data['alpha']
+#
+_wistia_data = {
+    'red': [(0.0, 0.8941176470588236, 0.8941176470588236),
+            (0.25, 1.0, 1.0),
+            (0.5, 1.0, 1.0),
+            (0.75, 1.0, 1.0),
+            (1.0, 0.9882352941176471, 0.9882352941176471)],
+    'green': [(0.0, 1.0, 1.0),
+              (0.25, 0.9098039215686274, 0.9098039215686274),
+              (0.5, 0.7411764705882353, 0.7411764705882353),
+              (0.75, 0.6274509803921569, 0.6274509803921569),
+              (1.0, 0.4980392156862745, 0.4980392156862745)],
+    'blue': [(0.0, 0.47843137254901963, 0.47843137254901963),
+             (0.25, 0.10196078431372549, 0.10196078431372549),
+             (0.5, 0.0, 0.0),
+             (0.75, 0.0, 0.0),
+             (1.0, 0.0, 0.0)],
+}
+
+
 datad = {
     'afmhot': _afmhot_data,
     'autumn': _autumn_data,
@@ -1963,3 +1994,4 @@ def gfunc32(x):
 datad['gist_stern'] = _gist_stern_data
 datad['gist_yarg'] = _gist_yarg_data
 datad['coolwarm'] = _coolwarm_data
+datad['Wistia'] = _wistia_data