Merge pull request #10810 from zhangeugenia/bugfix-for-issue-8818

efiring · web-flow · commit 566926136419 · 2018-03-22T21:05:54.000-10:00
Fix for plt.plot() does not support structured arrays as data= kwarg
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -49,7 +49,11 @@ def _plot_args_replacer(args, data):
         return ["y"]
     elif len(args) == 2:
         # this can be two cases: x,y or y,c
-        if not args[1] in data:
+        if (not args[1] in data and
+            not (hasattr(data, 'dtype') and
+                 hasattr(data.dtype, 'names') and
+                 data.dtype.names is not None and
+                 args[1] in data.dtype.names)):
             # this is not in data, so just assume that it is something which
             # will not get replaced (color spec or array like).
             return ["y", "c"]
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -584,6 +584,16 @@ def test_shaped_data():
     plt.plot(xdata[:, 1], xdata[1, :], 'o')
 
 
+def test_structured_data():
+    # support for stuctured data
+    pts = np.array([(1, 1), (2, 2)], dtype=[("ones", float), ("twos", float)])
+
+    # this should not read second name as a format and raise ValueError
+    fig, ax = plt.subplots(2)
+    ax[0].plot("ones", "twos", data=pts)
+    ax[1].plot("ones", "twos", "r", data=pts)
+
+
 @image_comparison(baseline_images=['const_xy'])
 def test_const_xy():
     fig = plt.figure()
