Merge pull request #17809 from meeseeksmachine/auto-backport-of-pr-17801-on-v3.3.x

tacaswell · web-flow · commit fe238a5e3c9f · 2020-06-30T20:22:11.000-04:00
Backport PR #17801 on branch v3.3.x (BUG: Fix implementation of _is_closed_polygon)
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -629,7 +629,7 @@ def _is_closed_polygon(X):
     presumably coordinates on a polygonal curve, in which case this function
     tests if that curve is closed.
     """
-    return np.all(X[0] == X[-1])
+    return np.allclose(X[0], X[-1], rtol=1e-10, atol=1e-13)
 
 
 def _find_closest_point_on_path(lc, point):
