Add rcParam hist.edgecolor

timhoffm · timhoffm · commit d35fe71a0f71 · 2018-11-25T16:01:36.000+01:00
diff --git a/doc/api/next_api_changes/2018-11-25-TH.rst b/doc/api/next_api_changes/2018-11-25-TH.rst
@@ -0,0 +1,6 @@
+New rcparam ``hist.edgecolor``
+``````````````````````````````
+The new  rcparam ``hist.edgecolor`` allows to expicitly define an edge color
+for the histogram bars. Previously, this could only be achieved by setting
+``patch.edgecolor`` and ``patch.force_edgecolor``, which may have affected
+other plot elements unwantedly.
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -6335,8 +6335,8 @@ def table(self, **kwargs):
     @_preprocess_data(replace_names=["x", 'weights'], label_namer="x")
     def hist(self, x, bins=None, range=None, density=None, weights=None,
              cumulative=False, bottom=None, histtype='bar', align='mid',
-             orientation='vertical', rwidth=None, log=False,
-             color=None, label=None, stacked=False, normed=None,
+             orientation='vertical', rwidth=None, log=False, color=None,
+             edgecolor=None, label=None, stacked=False, normed=None,
              **kwargs):
         """
         Plot a histogram.
@@ -6494,6 +6494,12 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
 
             Default is ``None``
 
+        edgecolor : color or array_like of colors or None, optional
+            Color spec or sequence of color specs, one per dataset.  Default
+            (``None``) :rc:`hist.edgecolor`. If that is ``None`` as well, the
+            default patch settings are used (:rc:`patch.edgecolor` and
+            :rc:`patch.force_edgecolor`).
+
         label : str or None, optional
             String, or sequence of strings to match multiple datasets.  Bar
             charts yield multiple patches per dataset, but only the first gets
@@ -6619,10 +6625,21 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
         else:
             color = mcolors.to_rgba_array(color)
             if len(color) != nx:
-                error_message = (
+                raise ValueError(
                     "color kwarg must have one color per data set. %d data "
                     "sets and %d colors were provided" % (nx, len(color)))
-                raise ValueError(error_message)
+
+        if edgecolor is None:
+            edgecolor = rcParams['hist.edgecolor']
+        if edgecolor is None:
+            edgecolor = [None] * nx
+        else:
+            edgecolor = mcolors.to_rgba_array(edgecolor)
+            if len(edgecolor) != nx:
+                raise ValueError(
+                    "edgecolor kwarg must have one color per data set. "
+                    "%d data sets and %d colors were provided" % (
+                        nx, len(edgecolor)))
 
         # If bins are not specified either explicitly or via range,
         # we need to figure out the range required for all datasets,
@@ -6715,7 +6732,7 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
                 _barfunc = self.bar
                 bottom_kwarg = 'bottom'
 
-            for m, c in zip(tops, color):
+            for m, c, ec in zip(tops, color, edgecolor):
                 if bottom is None:
                     bottom = np.zeros(len(m))
                 if stacked:
@@ -6724,7 +6741,8 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
                     height = m
                 patch = _barfunc(bins[:-1]+boffset, height, width,
                                  align='center', log=log,
-                                 color=c, **{bottom_kwarg: bottom})
+                                 color=c, edgecolor=ec,
+                                 **{bottom_kwarg: bottom})
                 patches.append(patch)
                 if stacked:
                     bottom[:] = m
@@ -6805,12 +6823,13 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
             # add patches in reverse order so that when stacking,
             # items lower in the stack are plotted on top of
             # items higher in the stack
-            for x, y, c in reversed(list(zip(xvals, yvals, color))):
+            for x, y, c, ec in reversed(list(zip(xvals, yvals, color,
+                                                 edgecolor))):
                 patches.append(self.fill(
                     x[:split], y[:split],
                     closed=True if fill else None,
                     facecolor=c,
-                    edgecolor=None if fill else c,
+                    edgecolor=ec if fill else c,
                     fill=fill if fill else None))
             for patch_list in patches:
                 for patch in patch_list:
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -353,6 +353,12 @@ def validate_color_or_auto(s):
     return validate_color(s)
 
 
+def validate_color_or_None(s):
+    if s is None:
+        return s
+    return validate_color(s)
+
+
 def validate_color_for_prop_cycle(s):
     # Special-case the N-th color cycle syntax, this obviously can not
     # go in the color cycle.
@@ -1049,6 +1055,7 @@ def _validate_linestyle(ls):
 
     ## Histogram properties
     'hist.bins': [10, validate_hist_bins],
+    'hist.edgecolor': [None, validate_color_or_None],
 
     ## Boxplot properties
     'boxplot.notch': [False, validate_bool],
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -3151,6 +3151,21 @@ def test_hist_labels():
     assert l[2][0].get_label() == '00'
 
 
+@check_figures_equal(extensions=['png'])
+def test_hist_bar_rc_edgecolor(fig_test, fig_ref):
+    with plt.rc_context({'hist.edgecolor': 'darkblue'}):
+        fig_test.subplots().hist([1, 5, 3], histtype='bar')
+    fig_ref.subplots().hist([1, 5, 3], histtype='bar', edgecolor='darkblue')
+
+
+@check_figures_equal(extensions=['png'])
+def test_hist_stepfilled_rc_edgecolor(fig_test, fig_ref):
+    with plt.rc_context({'hist.edgecolor': 'darkblue'}):
+        fig_test.subplots().hist([1, 5, 3], histtype='stepfilled')
+    fig_ref.subplots().hist([1, 5, 3], histtype='stepfilled',
+                            edgecolor='darkblue')
+
+
 @image_comparison(baseline_images=['transparent_markers'], remove_text=True)
 def test_transparent_markers():
     np.random.seed(0)
