Fix scatter edgecolor for unfilled points

has2k1 · has2k1 · commit 88cd5fd4037e · 2017-12-14T23:08:11.000-06:00
For unfilled markers, the edgecolor -- if specified -- has precedence over the facecolor. closes has2k1/plotnine#100
diff --git a/doc/api/api_changes/2017-12-14-HK.rst b/doc/api/api_changes/2017-12-14-HK.rst
@@ -0,0 +1,6 @@
+Scatter plot unfilled marker edgecolor
+--------------------------------------
+
+For :meth:`~matplotlib.axes.Axes.scatter`, when both the `facecolor`
+and `edgecolor` are specified for unfilled marker types, the `edgecolor`
+is used. Previously, the points took on the `facecolor`.
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -3873,8 +3873,8 @@ def scatter(self, x, y, s=None, c=None, marker=None, cmap=None, norm=None,
             If it is 'none', the patch boundary will not
             be drawn.
 
-            For non-filled markers, the `edgecolors` kwarg
-            is ignored and forced to 'face' internally.
+            For non-filled markers , the `edgecolors` kwarg (if it is not
+            None, 'face' or 'none') dictates the color of the marker.
 
         Returns
         -------
@@ -4024,7 +4024,8 @@ def scatter(self, x, y, s=None, c=None, marker=None, cmap=None, norm=None,
         path = marker_obj.get_path().transformed(
             marker_obj.get_transform())
         if not marker_obj.is_filled():
-            edgecolors = 'face'
+            if edgecolors is None:
+                edgecolors = 'face'
             linewidths = rcParams['lines.linewidth']
 
         offsets = np.column_stack([x, y])
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -1733,6 +1733,21 @@ def test_scatter_color():
         plt.scatter([1, 2, 3], [1, 2, 3], color=[1, 2, 3])
 
 
+@pytest.mark.parametrize(('facecolor', 'edgecolor', 'expected_color'), [
+    ('red', 'cyan', 'cyan'),
+    (None, 'cyan', 'cyan'),
+    ('red', None, 'red')
+])
+def test_scatter_edgecolor(facecolor, edgecolor, expected_color):
+    fig, ax = plt.subplots()
+    artist = ax.scatter(x=[1, 2, 3], y=[1, 2, 3], s=550,
+                        linewidth=5, marker='2',
+                        facecolor=facecolor,
+                        edgecolor=edgecolor)
+    result_color = artist.get_edgecolor()[0]
+    assert mcolors.to_hex(result_color) == mcolors.to_hex(expected_color)
+
+
 def test_as_mpl_axes_api():
     # tests the _as_mpl_axes api
     from matplotlib.projections.polar import PolarAxes
