added Tuukka's YAArrow fix for horiz and vertical lines

jdh2358 · jdh2358 · commit 25c2c9559aae · 2008-07-18T14:46:32.000Z
svn path=/branches/v0_91_maint/; revision=5787
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
@@ -712,6 +712,12 @@ def getpoints(self, x1,y1,x2,y2, k):
         and the distance from x2,y2 ot the returned points is k
         """
         x1,y1,x2,y2,k = map(float, (x1,y1,x2,y2,k))
+
+        if y2-y1 == 0:
+            return x2, y2+k, x2, y2-k
+        elif x2-x1 == 0:
+            return x2+k, y2, x2-k, y2
+
         m = (y2-y1)/(x2-x1)
         pm = -1./m
         a = 1
