MNT/DOC: Deprecate anchor in Axes3D.set_aspect

Aaratrika-Shelly · Aaratrika-Shelly · commit 1c0664c50f3e · 2025-08-08T19:18:31.000Z
diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -244,7 +244,7 @@ def _transformed_cube(self, vals):
                 (minx, maxy, maxz)]
         return proj3d._proj_points(xyzs, self.M)
 
-    def set_aspect(self, aspect, adjustable=None, anchor=None, share=False):
+    def set_aspect(self, aspect, adjustable=None, anchor=None):
         """
         Set the aspect ratios.
 
@@ -264,38 +264,24 @@ def set_aspect(self, aspect, adjustable=None, anchor=None, share=False):
             =========   ==================================================
 
         adjustable : None or {'box', 'datalim'}, optional
-            If not *None*, this defines which parameter will be adjusted to
-            meet the required aspect. See `.set_adjustable` for further
-            details.
+            This parameter is not used for 3D axes but is present for
+            compatibility with 2D axes. It will be ignored.
 
         anchor : None or str or 2-tuple of float, optional
-            If not *None*, this defines where the Axes will be drawn if there
-            is extra space due to aspect constraints. The most common way to
-            specify the anchor are abbreviations of cardinal directions:
-
-            =====   =====================
-            value   description
-            =====   =====================
-            'C'     centered
-            'SW'    lower left corner
-            'S'     middle of bottom edge
-            'SE'    lower right corner
-            etc.
-            =====   =====================
-
-            See `~.Axes.set_anchor` for further details.
-
-        share : bool, default: False
-            If ``True``, apply the settings to all shared Axes.
+            .. deprecated:: 3.11
+               The `anchor` parameter is not used for 3D axes and will be
+               removed in a future version. It is ignored.
 
         See Also
         --------
         mpl_toolkits.mplot3d.axes3d.Axes3D.set_box_aspect
         """
+        if anchor is not None:
+            _api.warn_deprecated("3.11", name="anchor", removal="3.13")
         _api.check_in_list(('auto', 'equal', 'equalxy', 'equalyz', 'equalxz'),
                            aspect=aspect)
-        super().set_aspect(
-            aspect='auto', adjustable=adjustable, anchor=anchor, share=share)
+        if adjustable is not None:
+            self.set_adjustable(adjustable)
         self._aspect = aspect
 
         if aspect in ('equal', 'equalxy', 'equalxz', 'equalyz'):
diff --git a/lib/mpl_toolkits/mplot3d/tests/test_my_deprecation.py b/lib/mpl_toolkits/mplot3d/tests/test_my_deprecation.py
@@ -0,0 +1,23 @@
+import pytest
+from matplotlib import _api
+import matplotlib.pyplot as plt
+import warnings
+
+
+def test_set_aspect_anchor_deprecation():
+    """Test that using the 'anchor' kwarg in set_aspect raises a warning."""
+    fig = plt.figure()
+    ax = fig.add_subplot(projection='3d')
+
+    # This should raise a warning
+    with pytest.warns(_api.MatplotlibDeprecationWarning,
+                     match="anchor"):
+        ax.set_aspect('equal', anchor='C')
+
+# This should NOT raise a warning
+    with warnings.catch_warnings(record=True) as record:
+        warnings.simplefilter("always")
+        ax.set_aspect('equal')
+        # Filter out known, unrelated warnings if necessary
+        # For now, let's assume no warnings should be present
+    assert len(record) == 0
