MNT: Remove PolyQuadMesh deprecations

The mask is no longer compressed and full 2D arrays are used for
the PolyQuadMesh objects.

Author: greglucas

doc/api/next_api_changes/removals/28492-GML.rst

@@ -0,0 +1,9 @@
+The ``.PolyQuadMesh`` class requires full 2D arrays of values
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Previously, if a masked array was input, the list of polygons within the collection
+would shrink to the size of valid polygons and users were required to keep track of
+which polygons were drawn and call ``set_array()`` with the smaller "compressed"
+array size. Passing the "compressed" and flattened array values will no longer
+work and the full 2D array of values (including the mask) should be passed
+to `.PolyQuadMesh.set_array`.

lib/matplotlib/collections.py

@@ -2252,14 +2252,8 @@ class PolyQuadMesh(_MeshData, PolyCollection):
     """
 
     def __init__(self, coordinates, **kwargs):
-        # We need to keep track of whether we are using deprecated compression
-        # Update it after the initializers
-        self._deprecated_compression = False
         super().__init__(coordinates=coordinates)
         PolyCollection.__init__(self, verts=[], **kwargs)
-        # Store this during the compression deprecation period
-        self._original_mask = ~self._get_unmasked_polys()
-        self._deprecated_compression = np.any(self._original_mask)
         # Setting the verts updates the paths of the PolyCollection
         # This is called after the initializers to make sure the kwargs
         # have all been processed and available for the masking calculations
@@ -2272,14 +2266,7 @@ def _get_unmasked_polys(self):
 
         # We want the shape of the polygon, which is the corner of each X/Y array
         mask = (mask[0:-1, 0:-1] | mask[1:, 1:] | mask[0:-1, 1:] | mask[1:, 0:-1])
-
-        if (getattr(self, "_deprecated_compression", False) and
-                np.any(self._original_mask)):
-            return ~(mask | self._original_mask)
-        # Take account of the array data too, temporarily avoiding
-        # the compression warning and resetting the variable after the call
-        with cbook._setattr_cm(self, _deprecated_compression=False):
-            arr = self.get_array()
+        arr = self.get_array()
         if arr is not None:
             arr = np.ma.getmaskarray(arr)
             if arr.ndim == 3:
@@ -2335,42 +2322,8 @@ def get_facecolor(self):
     def set_array(self, A):
         # docstring inherited
         prev_unmask = self._get_unmasked_polys()
-        # MPL <3.8 compressed the mask, so we need to handle flattened 1d input
-        # until the deprecation expires, also only warning when there are masked
-        # elements and thus compression occurring.
-        if self._deprecated_compression and np.ndim(A) == 1:
-            _api.warn_deprecated("3.8", message="Setting a PolyQuadMesh array using "
-                                 "the compressed values is deprecated. "
-                                 "Pass the full 2D shape of the original array "
-                                 f"{prev_unmask.shape} including the masked elements.")
-            Afull = np.empty(self._original_mask.shape)
-            Afull[~self._original_mask] = A
-            # We also want to update the mask with any potential
-            # new masked elements that came in. But, we don't want
-            # to update any of the compression from the original
-            mask = self._original_mask.copy()
-            mask[~self._original_mask] |= np.ma.getmask(A)
-            A = np.ma.array(Afull, mask=mask)
-            return super().set_array(A)
-        self._deprecated_compression = False
         super().set_array(A)
         # If the mask has changed at all we need to update
         # the set of Polys that we are drawing
         if not np.array_equal(prev_unmask, self._get_unmasked_polys()):
             self._set_unmasked_verts()
-
-    def get_array(self):
-        # docstring inherited
-        # Can remove this entire function once the deprecation period ends
-        A = super().get_array()
-        if A is None:
-            return
-        if self._deprecated_compression and np.any(np.ma.getmask(A)):
-            _api.warn_deprecated("3.8", message=(
-                "Getting the array from a PolyQuadMesh will return the full "
-                "array in the future (uncompressed). To get this behavior now "
-                "set the PolyQuadMesh with a 2D array .set_array(data2d)."))
-            # Setting an array of a polycollection required
-            # compressing the array
-            return np.ma.compressed(A)
-        return A

lib/matplotlib/tests/test_collections.py

@@ -965,11 +965,6 @@ def test_polyquadmesh_masked_vertices_array():
     # Poly version should have the same facecolors as the end of the quadmesh
     assert_array_equal(quadmesh_fc, polymesh.get_facecolor())
 
-    # Setting array with 1D compressed values is deprecated
-    with pytest.warns(mpl.MatplotlibDeprecationWarning,
-                      match="Setting a PolyQuadMesh"):
-        polymesh.set_array(np.ones(5))
-
     # We should also be able to call set_array with a new mask and get
     # updated polys
     # Remove mask, should add all polys back