Merge pull request #14485 from dstansby/14429-backport

dstansby · web-flow · commit 76ff8d02b756 · 2019-06-07T17:02:15.000+01:00
Backport #14429 on v3.1.x
diff --git a/lib/matplotlib/tests/test_units.py b/lib/matplotlib/tests/test_units.py
@@ -155,3 +155,14 @@ def test_jpl_barh_units():
 def test_empty_arrays():
     # Check that plotting an empty array with a dtype works
     plt.scatter(np.array([], dtype='datetime64[ns]'), np.array([]))
+
+
+def test_scatter_element0_masked():
+
+    times = np.arange('2005-02', '2005-03', dtype='datetime64[D]')
+
+    y = np.arange(len(times), dtype='float')
+    y[0] = np.nan
+    fig, ax = plt.subplots()
+    ax.scatter(times, y)
+    fig.canvas.draw()
diff --git a/lib/matplotlib/units.py b/lib/matplotlib/units.py
@@ -45,6 +45,7 @@ def default_units(x, axis):
 from numbers import Number
 
 import numpy as np
+from numpy import ma
 
 from matplotlib import cbook
 
@@ -128,6 +129,8 @@ def is_numlike(x):
         """
         if np.iterable(x):
             for thisx in x:
+                if thisx is ma.masked:
+                    continue
                 return isinstance(thisx, Number)
         else:
             return isinstance(x, Number)
