Add c, x, y shapes to unacceptable color sequence ValueError message

bcongdon · bcongdon · commit d813e0e5d041 · 2016-11-08T06:01:16.000-06:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -3987,7 +3987,9 @@ def scatter(self, x, y, s=None, c=None, marker=None, cmap=None, norm=None,
                 mcolors.to_rgba_array(colors)
             except ValueError:
                 # c not acceptable as PathCollection facecolor
-                raise ValueError("c not acceptable as color sequence")
+                msg = ("c of shape {0} not acceptable as a color sequence "
+                       "for x with shape {1}, y with shape {2}")
+                raise ValueError(msg.format(c.shape, x.shape, y.shape))
         else:
             colors = None  # use cmap, norm after collection is created
 
