Update find_nearest_contour to not use collections attribute

rcomer · rcomer · commit d5c0c15c424f · 2023-10-14T12:09:17.000+01:00
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -1409,13 +1409,13 @@ def find_nearest_contour(self, x, y, indices=None, pixel=True):
 
         Returns
         -------
-        contour : `.Collection`
-            The contour that is closest to ``(x, y)``.
+        path : int
+            The index of the path that is closest to ``(x, y)``.
         segment : int
-            The index of the `.Path` in *contour* that is closest to
+            The index within that closest path of the segment that is closest to
             ``(x, y)``.
         index : int
-            The index of the path segment in *segment* that is closest to
+            The index of the vertices within that segment that are closest to
             ``(x, y)``.
         xmin, ymin : float
             The point in the contour plot that is closest to ``(x, y)``.
@@ -1434,8 +1434,9 @@ def find_nearest_contour(self, x, y, indices=None, pixel=True):
         if self.filled:
             raise ValueError("Method does not support filled contours.")
 
+        paths = self.get_paths()
         if indices is None:
-            indices = range(len(self.collections))
+            indices = range(len(paths))
 
         d2min = np.inf
         conmin = None
@@ -1445,14 +1446,15 @@ def find_nearest_contour(self, x, y, indices=None, pixel=True):
         ymin = None
 
         point = np.array([x, y])
+        trans = self.get_transform()
 
         for icon in indices:
-            con = self.collections[icon]
-            trans = con.get_transform()
-            paths = con.get_paths()
+            path = paths[icon]
 
-            for segNum, linepath in enumerate(paths):
+            for segNum, linepath in enumerate(path._iter_connected_components()):
                 lc = linepath.vertices
+                if lc.size == 0:
+                    continue
                 # transfer all data points to screen coordinates if desired
                 if pixel:
                     lc = trans.transform(lc)
