MAINT: Vectorize the entire computation of the bar3d polygons

eric-wieser · eric-wieser · commit dcc48e431a09 · 2018-09-16T17:17:01.000-07:00
diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -2478,11 +2478,12 @@ def bar3d(self, x, y, z, dx, dy, dz, color=None,
             ),
         ])
 
-        polys = []
-        for xi, yi, zi, dxi, dyi, dzi in zip(x, y, z, dx, dy, dz):
-            corner = np.array([xi, yi, zi])
-            scale = np.array([dxi, dyi, dzi])
-            polys.extend(corner + scale * cuboid)
+        polys = np.empty(x.shape + cuboid.shape)
+        for i, p, dp in [(0, x, dx), (1, y, dy), (2, z, dz)]:
+            polys[..., i] = p + dp * cuboid
+
+        # collapse the first two axes
+        polys = polys.reshape((-1,) + polys.shape[2:])
 
         facecolors = []
         if color is None:
