Merge pull request #16692 from ImportanceOfBeingErnest/marker-for-lines

QuLogic · web-flow · commit 071da48d9253 · 2020-03-12T17:28:30.000-04:00
Allow MarkerStyle instances as input for lines
diff --git a/doc/users/next_whats_new/2020-03-05_markerstyle-for-lines.rst b/doc/users/next_whats_new/2020-03-05_markerstyle-for-lines.rst
@@ -0,0 +1,7 @@
+Lines now accept ``MarkerStyle`` instances as input
+---------------------------------------------------
+Similar to `~.Axes.scatter`, `~.Axes.plot` and `~.lines.Line2D` now accept
+`~.markers.MarkerStyle` instances as input for the *marker* parameter::
+
+    plt.plot(..., marker=matplotlib.markers.MarkerStyle("D"))
+
diff --git a/lib/matplotlib/lines.py b/lib/matplotlib/lines.py
@@ -1197,7 +1197,7 @@ def set_marker(self, marker):
 
         Parameters
         ----------
-        marker : marker style
+        marker : marker style string, `~.path.Path` or `~.markers.MarkerStyle`
             See `~matplotlib.markers` for full description of possible
             arguments.
         """
diff --git a/lib/matplotlib/markers.py b/lib/matplotlib/markers.py
@@ -283,6 +283,8 @@ def set_marker(self, marker):
               marker in self.markers):
             self._marker_function = getattr(
                 self, '_set_' + self.markers[marker])
+        elif isinstance(marker, MarkerStyle):
+            self.__dict__.update(marker.__dict__)
         else:
             try:
                 Path(marker)
@@ -291,8 +293,9 @@ def set_marker(self, marker):
                 raise ValueError('Unrecognized marker style {!r}'
                                  .format(marker)) from err
 
-        self._marker = marker
-        self._recache()
+        if not isinstance(marker, MarkerStyle):
+            self._marker = marker
+            self._recache()
 
     def get_path(self):
         return self._path
diff --git a/lib/matplotlib/tests/test_lines.py b/lib/matplotlib/tests/test_lines.py
@@ -7,10 +7,13 @@
 
 from cycler import cycler
 import numpy as np
+from numpy.testing import assert_array_equal
 import pytest
 
 import matplotlib
 import matplotlib.lines as mlines
+from matplotlib.markers import MarkerStyle
+from matplotlib.path import Path
 import matplotlib.pyplot as plt
 from matplotlib.testing.decorators import image_comparison, check_figures_equal
 
@@ -194,3 +197,23 @@ def test_nan_is_sorted():
 def test_step_markers(fig_test, fig_ref):
     fig_test.subplots().step([0, 1], "-o")
     fig_ref.subplots().plot([0, 0, 1], [0, 1, 1], "-o", markevery=[0, 2])
+
+
+def test_marker_as_markerstyle():
+    fig, ax = plt.subplots()
+    line, = ax.plot([2, 4, 3], marker=MarkerStyle("D"))
+    fig.canvas.draw()
+    assert line.get_marker() == "D"
+
+    # continue with smoke tests:
+    line.set_marker("s")
+    fig.canvas.draw()
+    line.set_marker(MarkerStyle("o"))
+    fig.canvas.draw()
+    # test Path roundtrip
+    triangle1 = Path([[-1., -1.], [1., -1.], [0., 2.], [0., 0.]], closed=True)
+    line2, = ax.plot([1, 3, 2], marker=MarkerStyle(triangle1), ms=22)
+    line3, = ax.plot([0, 2, 1], marker=triangle1, ms=22)
+
+    assert_array_equal(line2.get_marker().vertices, triangle1.vertices)
+    assert_array_equal(line3.get_marker().vertices, triangle1.vertices)
