FIX

jklymak · jklymak · commit 7ce4a7e7e8a3 · 2021-11-19T21:07:29.000+01:00
diff --git a/lib/matplotlib/colorbar.py b/lib/matplotlib/colorbar.py
@@ -1149,18 +1149,22 @@ def _mesh(self):
             return (Y, X, extendlen)
 
     def _forward_boundaries(self, x):
+        # map boundaries equally between 0 and 1...
         b = self._boundaries
         db = b[-1] - b[0]
-        y = np.interp(x, b, np.linspace(0, db, len(b)))
+        y = np.interp(x, b, np.linspace(0, 1, len(b)))
         # the following avoids ticks in the extends:
         eps = db * 1e-6
-        y[x < b[0]-eps] = -1 * db
-        y[x > b[-1]+eps] = b[-1] + db
+        # map these _well_ out of bounds to keep any ticks out
+        # of the extends region...
+        y[x < b[0]-eps] = -1
+        y[x > b[-1]+eps] = 2
         return y
 
     def _inverse_boundaries(self, x):
+        # invert the above...
         b = self._boundaries
-        return np.interp(x, np.linspace(0, b[-1]-b[0], len(b)), b)
+        return np.interp(x, np.linspace(0, 1, len(b)), b)
 
     def _reset_locator_formatter_scale(self):
         """
