Fix for case where no alpha is given.

paulkirow · paulkirow · commit 3b60c7c4a8f1 · 2016-04-01T20:27:08.000-04:00
diff --git a/lib/matplotlib/cm.py b/lib/matplotlib/cm.py
@@ -277,10 +277,10 @@ def to_rgba(self, x, alpha=None, bytes=False, norm=True):
             x = self.norm(x)
 
         try:
-            alpha = ma.asarray(alpha)
-            if alpha.ndim == 1 and alpha.shape == x.shape:
+            np_alpha = ma.asarray(alpha)
+            if np_alpha.ndim == 1 and np_alpha.shape == x.shape:
                 rgba = self.cmap(x, bytes=bytes)
-                rgba[0:, 3] = alpha
+                rgba[0:, 3] = np_alpha
                 return rgba
         except AttributeError:
             # e.g., alpha is not an array;
diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -680,9 +680,9 @@ def set_alpha(self, alpha):
         if alpha is not None:
             try:
                 # Check if alpha is an array of matching size
-                alpha = ma.asarray(alpha)
-                if alpha.ndim == 1:
-                    artist.Artist.set_alpha(self, alpha)
+                np_alpha = ma.asarray(alpha)
+                if np_alpha.ndim == 1:
+                    artist.Artist.set_alpha(self, np_alpha)
                     return
             except AttributeError:
                 pass
