BUG : change set -> tuple for 2.6 compatibility

tacaswell · tacaswell · commit b89307bc3840 · 2014-12-29T09:00:29.000-05:00
diff --git a/lib/matplotlib/quiver.py b/lib/matplotlib/quiver.py
@@ -405,7 +405,7 @@ class Quiver(mcollections.PolyCollection):
     in the draw() method.
     """
 
-    _PIVOT_VALS = {'tail', 'tip', 'mid', 'middle'}
+    _PIVOT_VALS = ('tail', 'mid', 'middle', 'tip')
 
     @docstring.Substitution(_quiver_doc)
     def __init__(self, ax, *args, **kw):
