MNT: simplify validation logic

tacaswell · tacaswell · commit 591fc21b9a6a · 2020-03-04T22:43:58.000-05:00
hat tip to @anntzer
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -1638,22 +1638,19 @@ def _process_layout(layout):
 
         def _do_layout(gs, layout, unique_ids, nested):
             rows, cols = layout.shape
-            covered = np.zeros((rows, cols), dtype=bool)
             output = dict()
 
-            for j, k in np.argwhere(layout == empty_sentinel):
-                covered[j, k] = True
-
             for name in unique_ids:
+                if name == empty_sentinel:
+                    continue
+
                 indx = np.argwhere(layout == name)
                 start_row, start_col = np.min(indx, axis=0)
                 end_row, end_col = np.max(indx, axis=0) + 1
                 slc = (slice(start_row, end_row), slice(start_col, end_col))
-                if np.any(covered[slc]):
+
+                if (layout[slc] != name).any():
                     raise ValueError
-                covered[slc] = True
-                if name == empty_sentinel:
-                    continue
 
                 if hasattr(name, 'set_subplotspec'):
                     ax = name
