BUG : allows empty event lists to be passed in

tacaswell · tacaswell · commit 052542d6c78c · 2014-02-03T18:03:48.000-05:00
fixes matplotlib#2786
diff --git a/lib/matplotlib/axes.py b/lib/matplotlib/axes.py
@@ -3988,18 +3988,24 @@ def eventplot(self, positions, orientation='horizontal', lineoffsets=1,
             colls.append(coll)
 
         if len(positions) > 0:
-            minpos = min(position.min() for position in positions)
-            maxpos = max(position.max() for position in positions)
-
-            minline = (lineoffsets - linelengths).min()
-            maxline = (lineoffsets + linelengths).max()
-
-            if colls[0].is_horizontal():
-                corners = (minpos, minline), (maxpos, maxline)
-            else:
-                corners = (minline, minpos), (maxline, maxpos)
-            self.update_datalim(corners)
-            self.autoscale_view()
+            # try to get min/max
+            min_max = [(np.min(_p), np.max(_p)) for _p in positions
+                       if len(_p) > 0]
+            # if we have any non-empty positions, try to autoscale
+            if len(min_max) > 0:
+                mins, maxes = zip(*min_max)
+                minpos = np.min(mins)
+                maxpos = np.max(maxes)
+
+                minline = (lineoffsets - linelengths).min()
+                maxline = (lineoffsets + linelengths).max()
+
+                if colls[0].is_horizontal():
+                    corners = (minpos, minline), (maxpos, maxline)
+                else:
+                    corners = (minline, minpos), (maxline, maxpos)
+                self.update_datalim(corners)
+                self.autoscale_view()
 
         return colls
 
