Small cleanup to StepPatch._update_path.

anntzer · anntzer · commit a6f119fdf939 · 2020-11-13T11:39:39.000+01:00
- No need to explicitly convert to arrays in `codes`; `concatenate`
  will do that for us.
- We only need to compute the Path once at the end of the loop
  (all other iterations are just thrown away).
- Both `verts` and `codes` are being concatenated along their
  first axis, so using different stackers (`vstack`/`hstack`) just
  hides that symmetry.
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
@@ -1009,8 +1009,8 @@ def _update_path(self):
             else:
                 xy = np.column_stack([y, x])
             verts.append(xy)
-            codes.append(np.array([Path.MOVETO] + [Path.LINETO]*(len(xy)-1)))
-            self._path = Path(np.vstack(verts), np.hstack(codes))
+            codes.append([Path.MOVETO] + [Path.LINETO]*(len(xy)-1))
+        self._path = Path(np.concatenate(verts), np.concatenate(codes))
 
     def get_data(self):
         """Get `.StepPatch` values, edges and baseline as namedtuple."""
