Merge pull request #10584 from matplotlib/auto-backport-of-pr-10578

tacaswell · web-flow · commit 88c9d9bf3253 · 2018-02-24T10:52:04.000-05:00
Backport PR #10578 on branch v2.2.x
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -1270,10 +1270,11 @@ def eventplot(self, positions, orientation='horizontal', lineoffsets=1,
                 minline = (lineoffsets - linelengths).min()
                 maxline = (lineoffsets + linelengths).max()
 
-                if colls[0].is_horizontal():
-                    corners = (minpos, minline), (maxpos, maxline)
-                else:
+                if (orientation is not None and
+                        orientation.lower() == "vertical"):
                     corners = (minline, minpos), (maxline, maxpos)
+                else:  # "horizontal", None or "none" (see EventCollection)
+                    corners = (minpos, minline), (maxpos, maxline)
                 self.update_datalim(corners)
                 self.autoscale_view()
 
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -3237,6 +3237,17 @@ def test_empty_eventplot():
     plt.draw()
 
 
+@pytest.mark.parametrize('data, orientation', product(
+    ([[]], [[], [0, 1]], [[0, 1], []]),
+    ('_empty', 'vertical', 'horizontal', None, 'none')))
+def test_eventplot_orientation(data, orientation):
+    """Introduced when fixing issue #6412. """
+    opts = {} if orientation == "_empty" else {'orientation': orientation}
+    fig, ax = plt.subplots(1, 1)
+    ax.eventplot(data, **opts)
+    plt.draw()
+
+
 @image_comparison(baseline_images=['marker_styles'], extensions=['png'],
                   remove_text=True)
 def test_marker_styles():
