FIX: remove LinearTransform

jklymak · jklymak · commit 4699c0cbfa3e · 2021-01-08T08:39:01.000-08:00
diff --git a/lib/matplotlib/scale.py b/lib/matplotlib/scale.py
@@ -90,10 +90,6 @@ def __deepcopy__(self, memo):
     __copy__ = __deepcopy__
 
 
-class LinearTransform(_CopyableTransformMixin, IdentityTransform):
-    pass
-
-
 class LinearScale(ScaleBase):
     """
     The default linear scale.
@@ -125,7 +121,7 @@ def get_transform(self):
         Return the transform for linear scaling, which is just the
         `~matplotlib.transforms.IdentityTransform`.
         """
-        return LinearTransform()
+        return IdentityTransform()
 
 
 class FuncTransform(_CopyableTransformMixin, Transform):
diff --git a/lib/matplotlib/tests/test_transforms.py b/lib/matplotlib/tests/test_transforms.py
@@ -501,8 +501,8 @@ def test_str_transform():
         CompositeGenericTransform(
             TransformWrapper(
                 BlendedAffine2D(
-                    LinearTransform(),
-                    LinearTransform())),
+                    IdentityTransform(),
+                    IdentityTransform())),
             CompositeAffine2D(
                 Affine2D(
                     [[1. 0. 0.]
@@ -521,8 +521,8 @@ def test_str_transform():
             PolarAffine(
                 TransformWrapper(
                     BlendedAffine2D(
-                        LinearTransform(),
-                        LinearTransform())),
+                        IdentityTransform(),
+                        IdentityTransform())),
                 LockableBbox(
                     Bbox(x0=0.0, y0=0.0, x1=6.283185307179586, y1=1.0),
                     [[-- --]
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -2062,6 +2062,14 @@ def frozen(self):
         # docstring inherited
         return self
 
+    def __deepcopy__(self, memo):
+        """
+        The identity transform does not need to lock out deepcopy
+        """
+        return self.frozen()
+
+    __copy__ = __deepcopy__
+
     __str__ = _make_str_method()
 
     def get_matrix(self):
