matplotlib · tacaswell · Apr 28, 2016 · Apr 11, 2016 · Apr 11, 2016 · Apr 11, 2016
diff --git a/examples/pylab_examples/color_demo.py b/examples/pylab_examples/color_demo.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 """
-matplotlib gives you 4 ways to specify colors,
+matplotlib gives you 5 ways to specify colors,
 
     1) as a single letter string, ala MATLAB
 
@@ -11,6 +11,9 @@
     4) as a string representing a floating point number
        from 0 to 1, corresponding to shades of gray.
 
+    5) as a special color "Cn", where n is a number 0-9 specifying the
+       nth color in the currently active color cycle.
+
 See help(colors) for more info.
 """
 import matplotlib.pyplot as plt
@@ -20,8 +23,8 @@
 #subplot(111, facecolor='#ababab')
 t = np.arange(0.0, 2.0, 0.01)
 s = np.sin(2*np.pi*t)
-plt.plot(t, s, 'y')
-plt.xlabel('time (s)', color='r')
+plt.plot(t, s, 'C1')
+plt.xlabel('time (s)', color='C1')
 plt.ylabel('voltage (mV)', color='0.5')  # grayscale color
 plt.title('About as silly as it gets, folks', color='#afeeee')
 plt.show()
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -4,6 +4,7 @@
 from matplotlib.externals import six
 from matplotlib.externals.six.moves import reduce, xrange, zip, zip_longest
 
+import itertools
 import math
 import warnings
 
@@ -2458,7 +2459,7 @@ def pie(self, x, explode=None, labels=None, colors=None,
         Call signature::
 
           pie(x, explode=None, labels=None,
-              colors=('b', 'g', 'r', 'c', 'm', 'y', 'k', 'w'),
+              colors=None,
               autopct=None, pctdistance=0.6, shadow=False,
               labeldistance=1.1, startangle=None, radius=None,
               counterclock=True, wedgeprops=None, textprops=None,
@@ -2478,7 +2479,8 @@ def pie(self, x, explode=None, labels=None, colors=None,
 
           *colors*: [ *None* | color sequence ]
             A sequence of matplotlib color args through which the pie chart
-            will cycle.
+            will cycle.  If `None`, will use the colors in the currently
+            active cycle.
 
           *labels*: [ *None* | len(x) sequence of strings ]
             A sequence of strings providing the labels for each wedge
@@ -2567,7 +2569,12 @@ def pie(self, x, explode=None, labels=None, colors=None,
         if len(x) != len(explode):
             raise ValueError("'explode' must be of length 'x'")
         if colors is None:
-            colors = ('b', 'g', 'r', 'c', 'm', 'y', 'k', 'w')
+            get_next_color = self._get_patches_for_fill.get_next_color
+        else:
+            color_cycle = itertools.cycle(colors)
+
+            def get_next_color():
+                return six.next(color_cycle)
 
         if radius is None:
             radius = 1
@@ -2603,7 +2610,7 @@ def pie(self, x, explode=None, labels=None, colors=None,
 
             w = mpatches.Wedge((x, y), radius, 360. * min(theta1, theta2),
                             360. * max(theta1, theta2),
-                            facecolor=colors[i % len(colors)],
+                            facecolor=get_next_color(),
                             **wedgeprops)
             slices.append(w)
             self.add_patch(w)
@@ -3023,8 +3030,8 @@ def xywhere(xs, ys, mask):
             l0, = self.plot(x, y, fmt, label='_nolegend_', **kwargs)
 
         if ecolor is None:
-            if l0 is None and 'color' in self._get_lines._prop_keys:
-                ecolor = next(self._get_lines.prop_cycler)['color']
+            if l0 is None:
+                ecolor = self._get_lines.get_next_color()
             else:
                 ecolor = l0.get_color()
 
@@ -3846,7 +3853,10 @@ def scatter(self, x, y, s=None, c=None, marker='o', cmap=None, norm=None,
             if facecolors is not None:
                 c = facecolors
             else:
-                c = 'b'  # The original default
+                if rcParams['_internal.classic_mode']:
+                    c = 'b'  # The original default
+                else:
+                    c = self._get_patches_for_fill.get_next_color()
 
         if edgecolors is None and not rcParams['_internal.classic_mode']:
             edgecolors = 'face'
@@ -6019,9 +6029,8 @@ def _normalize_input(inp, ename='input'):
                 raise ValueError(
                     'weights should have the same shape as x')
 
-        if color is None and 'color' in self._get_lines._prop_keys:
-            color = [next(self._get_lines.prop_cycler)['color']
-                     for i in xrange(nx)]
+        if color is None:
+            color = [self._get_lines.get_next_color() for i in xrange(nx)]
         else:
             color = mcolors.colorConverter.to_rgba_array(color)
             if len(color) != nx:
@@ -7507,6 +7516,12 @@ def violin(self, vpstats, positions=None, vert=True, widths=0.5,
             perp_lines = self.vlines
             par_lines = self.hlines
 
+        if rcParams['_internal.classic_mode']:
+            fillcolor = 'y'
+            edgecolor = 'r'
+        else:
+            fillcolor = edgecolor = self._get_lines.get_next_color()
+
         # Render violins
         bodies = []
         for stats, pos, width in zip(vpstats, positions, widths):
@@ -7517,7 +7532,7 @@ def violin(self, vpstats, positions=None, vert=True, widths=0.5,
             bodies += [fill(stats['coords'],
                             -vals + pos,
                             vals + pos,
-                            facecolor='y',
+                            facecolor=fillcolor,
                             alpha=0.3)]
             means.append(stats['mean'])
             mins.append(stats['min'])
@@ -7527,20 +7542,24 @@ def violin(self, vpstats, positions=None, vert=True, widths=0.5,
 
         # Render means
         if showmeans:
-            artists['cmeans'] = perp_lines(means, pmins, pmaxes, colors='r')
+            artists['cmeans'] = perp_lines(means, pmins, pmaxes,
+                                           colors=edgecolor)
 
         # Render extrema
         if showextrema:
-            artists['cmaxes'] = perp_lines(maxes, pmins, pmaxes, colors='r')
-            artists['cmins'] = perp_lines(mins, pmins, pmaxes, colors='r')
-            artists['cbars'] = par_lines(positions, mins, maxes, colors='r')
+            artists['cmaxes'] = perp_lines(maxes, pmins, pmaxes,
+                                           colors=edgecolor)
+            artists['cmins'] = perp_lines(mins, pmins, pmaxes,
+                                          colors=edgecolor)
+            artists['cbars'] = par_lines(positions, mins, maxes,
+                                         colors=edgecolor)
 
         # Render medians
         if showmedians:
             artists['cmedians'] = perp_lines(medians,
                                              pmins,
                                              pmaxes,
-                                             colors='r')
+                                             colors=edgecolor)
 
         return artists
 

diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -52,6 +52,7 @@ def _process_plot_format(fmt):
     * 'ko': black circles
     * '.b': blue dots
     * 'r--': red dashed lines
+    * 'C2--': the third color in the color cycle, dashed lines
 
     .. seealso::
 
@@ -97,7 +98,9 @@ def _process_plot_format(fmt):
 
     chars = [c for c in fmt]
 
-    for c in chars:
+    i = 0
+    while i < len(chars):
+        c = chars[i]
         if c in mlines.lineStyles:
             if linestyle is not None:
                 raise ValueError(
@@ -113,9 +116,14 @@ def _process_plot_format(fmt):
                 raise ValueError(
                     'Illegal format string "%s"; two color symbols' % fmt)
             color = c
+        elif c == 'C' and i < len(chars) - 1:
+            color_cycle_number = int(chars[i + 1])
+            color = mcolors.colorConverter._get_nth_color(color_cycle_number)
+            i += 1
         else:
             raise ValueError(
                 'Unrecognized character %c in format string' % c)
+        i += 1
 
     if linestyle is None and marker is None:
         linestyle = rcParams['lines.linestyle']
@@ -161,6 +169,10 @@ def set_prop_cycle(self, *args, **kwargs):
         else:
             prop_cycler = cycler(*args, **kwargs)
 
+        # Make sure the cycler always has at least one color
+        if 'color' not in prop_cycler.keys:
+            prop_cycler = prop_cycler * cycler('color', ['k'])
+
         self.prop_cycler = itertools.cycle(prop_cycler)
         # This should make a copy
         self._prop_keys = prop_cycler.keys
@@ -186,6 +198,12 @@ def __call__(self, *args, **kwargs):
         ret = self._grab_next_args(*args, **kwargs)
         return ret
 
+    def get_next_color(self):
+        """
+        Return the next color in the cycle.
+        """
+        return six.next(self.prop_cycler)['color']
+
     def set_lineprops(self, line, **kwargs):
         assert self.command == 'plot', 'set_lineprops only works with "plot"'
         line.set(**kwargs)

diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -31,6 +31,12 @@
     - k: black
     - w: white
 
+To use the colors that are part of the active color cycle in the current style,
+use `C` followed by a digit.  For example:
+
+    - `C0`: The first color in the cycle
+    - `C1`: The second color in the cycle
+
 Gray shades can be given as a string encoding a float in the 0-1 range, e.g.::
 
     color = '0.75'
@@ -67,6 +73,19 @@
 
 def is_color_like(c):
     'Return *True* if *c* can be converted to *RGB*'
+
+    # Special-case the N-th color cycle syntax, because its parsing
+    # needs to be deferred.  We may be reading a value from rcParams
+    # here before the color_cycle rcParam has been parsed.
+    if isinstance(c, bytes):
+        match = re.match(b'^C[0-9]$', c)
+        if match is not None:
+            return True
+    elif isinstance(c, six.text_type):
+        match = re.match('^C[0-9]$', c)
+        if match is not None:
+            return True
+
     try:
         colorConverter.to_rgb(c)
         return True
@@ -114,9 +133,36 @@ class ColorConverter(object):
         'k': (0, 0, 0),
         'w': (1, 1, 1)}
 
+    _prop_cycler = None
+
     cache = {}
     CN_LOOKUPS = [COLOR_NAMES[k] for k in ['css4', 'xkcd']]
 
+    @classmethod
+    def _get_nth_color(cls, val):
+        """
+        Get the Nth color in the current color cycle.  If N is greater
+        than the number of colors in the cycle, it is wrapped around.
+        """
+        from matplotlib.rcsetup import cycler
+        from matplotlib import rcParams
+
+        prop_cycler = rcParams['axes.prop_cycle']
+        if prop_cycler is None and 'axes.color_cycle' in rcParams:
+            clist = rcParams['axes.color_cycle']
+            prop_cycler = cycler('color', clist)
+
+        colors = prop_cycler._transpose()['color']
+        return colors[val % len(colors)]
+
+    @classmethod
+    def _parse_nth_color(cls, val):
+        match = re.match('^C[0-9]$', val)
+        if match is not None:
+            return cls._get_nth_color(int(val[1]))
+
+        raise ValueError("Not a color cycle color")
+
     def to_rgb(self, arg):
         """
         Returns an *RGB* tuple of three floats from 0-1.
@@ -154,6 +200,10 @@ def to_rgb(self, arg):
                 argl = arg.lower()
                 color = self.colors.get(argl, None)
                 if color is None:
+                    try:
+                        argl = self._parse_nth_color(arg)
+                    except ValueError:
+                        pass
                     for cmapping in self.CN_LOOKUPS:
                         str1 = cmapping.get(argl, argl)
                         if str1 != argl:

diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -848,7 +848,7 @@ def validate_animation_writer_path(p):
     # line props
     'lines.linewidth':       [2.5, validate_float],  # line width in points
     'lines.linestyle':       ['-', six.text_type],             # solid line
-    'lines.color':           ['b', validate_color],  # blue
+    'lines.color':           ['C0', validate_color],  # first color in color cycle
     'lines.marker':          ['None', six.text_type],     # black
     'lines.markeredgewidth': [1.0, validate_float],
     'lines.markersize':      [6, validate_float],    # markersize, in points
@@ -867,7 +867,7 @@ def validate_animation_writer_path(p):
     ## patch props
     'patch.linewidth':   [None, validate_float_or_None],  # line width in points
     'patch.edgecolor':   ['k', validate_color],  # black
-    'patch.facecolor':   ['#1f77b4', validate_color],  # blue (first color in color cycle)
+    'patch.facecolor':   ['C0', validate_color],  # first color in color cycle
     'patch.antialiased': [True, validate_bool],  # antialiased (no jaggies)
 
     ## Histogram properties
@@ -885,27 +885,27 @@ def validate_animation_writer_path(p):
     'boxplot.showfliers': [True, validate_bool],
     'boxplot.meanline': [False, validate_bool],
 
-    'boxplot.flierprops.color': ['b', validate_color],
+    'boxplot.flierprops.color': ['C0', validate_color],
     'boxplot.flierprops.marker': ['+', six.text_type],
     'boxplot.flierprops.markerfacecolor': ['auto', validate_color_or_auto],
     'boxplot.flierprops.markeredgecolor': ['k', validate_color],
     'boxplot.flierprops.markersize': [6, validate_float],
     'boxplot.flierprops.linestyle': ['none', six.text_type],
     'boxplot.flierprops.linewidth': [1.0, validate_float],
 
-    'boxplot.boxprops.color': ['b', validate_color],
+    'boxplot.boxprops.color': ['C0', validate_color],
     'boxplot.boxprops.linewidth': [1.0, validate_float],
     'boxplot.boxprops.linestyle': ['-', six.text_type],
 
-    'boxplot.whiskerprops.color': ['b', validate_color],
+    'boxplot.whiskerprops.color': ['C0', validate_color],
     'boxplot.whiskerprops.linewidth': [1.0, validate_float],
     'boxplot.whiskerprops.linestyle': ['--', six.text_type],
 
     'boxplot.capprops.color': ['k', validate_color],
     'boxplot.capprops.linewidth': [1.0, validate_float],
     'boxplot.capprops.linestyle': ['-', six.text_type],
 
-    'boxplot.medianprops.color': ['r', validate_color],
+    'boxplot.medianprops.color': ['C1', validate_color],
     'boxplot.medianprops.linewidth': [1.0, validate_float],
     'boxplot.medianprops.linestyle': ['-', six.text_type],
 
@@ -1016,7 +1016,10 @@ def validate_animation_writer_path(p):
     'axes.formatter.use_mathtext': [False, validate_bool],
     'axes.formatter.useoffset': [True, validate_bool],
     'axes.unicode_minus': [True, validate_bool],
-    'axes.color_cycle': [['b', 'g', 'r', 'c', 'm', 'y', 'k'],
+    'axes.color_cycle': [
+        ['#1f77b4', '#ff7f0e', '#2ca02c', '#d62728',
+         '#9467bd', '#8c564b', '#e377c2', '#7f7f7f',
+         '#bcbd22', '#17becf'],
                          deprecate_axes_colorcycle],  # cycle of plot
                                                       # line colors
     # This entry can be either a cycler object or a

diff --git a/lib/matplotlib/sankey.py b/lib/matplotlib/sankey.py
@@ -45,6 +45,7 @@
 from matplotlib.transforms import Affine2D
 from matplotlib import verbose
 from matplotlib import docstring
+from matplotlib import rcParams
 
 __author__ = "Kevin L. Davies"
 __credits__ = ["Yannick Copin"]
@@ -770,11 +771,15 @@ def _get_angle(a, r):
             print("lrpath\n", self._revert(lrpath))
             xs, ys = list(zip(*vertices))
             self.ax.plot(xs, ys, 'go-')
-        patch = PathPatch(Path(vertices, codes),
-                          fc=kwargs.pop('fc', kwargs.pop('facecolor',
-                                        '#bfd1d4')),  # Custom defaults
-                          lw=kwargs.pop('lw', kwargs.pop('linewidth', 0.5)),
-                          **kwargs)
+        if rcParams['_internal.classic_mode']:
+            fc = kwargs.pop('fc', kwargs.pop('facecolor', '#bfd1d4'))
+            lw = kwargs.pop('lw', kwargs.pop('linewidth', 0.5))
+        else:
+            fc = kwargs.pop('fc', kwargs.pop('facecolor', None))
+            lw = kwargs.pop('lw', kwargs.pop('linewidth', None))
+        if fc is None:
+            fc = six.next(self.ax._get_patches_for_fill.prop_cycler)['color']
+        patch = PathPatch(Path(vertices, codes), fc=fc, lw=lw, **kwargs)
         self.ax.add_patch(patch)
 
         # Add the path labels.