FIX: make y/rlims out of order raise a Value Error

jklymak · jklymak · commit 32e9b42e891b · 2018-09-26T20:52:38.000-07:00
diff --git a/lib/matplotlib/projections/polar.py b/lib/matplotlib/projections/polar.py
@@ -1240,8 +1240,8 @@ def set_ylim(self, bottom=None, top=None, emit=True, auto=False,
 
         Notes
         -----
-        The `bottom` value must be less than the `top` value; if they are not,
-        a warning is emmited and the values are swapped.
+        The `bottom` value must be less than the `top` value, or a
+        ValueError is raised.
         """
 
         if ymin is not None:
@@ -1257,9 +1257,9 @@ def set_ylim(self, bottom=None, top=None, emit=True, auto=False,
             else:
                 top = ymax
         if bottom >= top:
-            warnings.warn('polar axes y/r limits must be increasing;'
-                          'swapping order')
-            bottom, top = top, bottom
+            raise ValueError('polar axes y/r-limits must be increasing; '
+                             'i.e. bottom < top')
+
         return super().set_ylim(bottom=bottom, top=top, emit=emit, auto=auto)
 
     def get_rlabel_position(self):
