BF: allow CoordinateMap subclasses on L & R of ==

matthew-brett · matthew-brett · commit 5dc0d33c0dda · 2013-01-16T21:41:59.000Z
We were previously only testing subclasses in one direction, but a
subclass on the left or the right should be OK.  Test.
diff --git a/nipy/core/reference/coordinate_map.py b/nipy/core/reference/coordinate_map.py
@@ -442,7 +442,8 @@ def _checkfunction(self):
         out = self(inp)
 
     def __eq__(self, other):
-        return (isinstance(other, self.__class__)
+        return ((isinstance(other, self.__class__) or
+                 isinstance(self, other.__class__))
                 and (self.function == other.function)
                 and (self.function_domain ==
                      other.function_domain)
@@ -956,7 +957,8 @@ def __repr__(self):
 
     def __eq__(self, other):
         # Must be subclasses
-        if not isinstance(other, self.__class__):
+        if not (isinstance(other, self.__class__) or
+                isinstance(self, other.__class__)):
             return False
         if np.any(self.affine - other.affine): # for objects
             if not np.allclose(self.affine, other.affine): # for numerical
diff --git a/nipy/core/reference/tests/test_coordinate_map.py b/nipy/core/reference/tests/test_coordinate_map.py
@@ -956,6 +956,23 @@ def test_dtype_cmap_inverses():
         assert_array_equal(rcm_cmap(coord), out_arr)
 
 
+def test_subtype_equalities():
+    # Check cmap compare equal if subtypes, on either side
+    in_cs = CoordinateSystem('ijk')
+    out_cs = CoordinateSystem('xyz')
+    f = lambda x : x + 1
+    cmap = CoordinateMap(in_cs, out_cs, f)
+    class CM2(CoordinateMap): pass
+    cmap2 = CM2(in_cs, out_cs, f)
+    assert_equal(cmap, cmap2)
+    assert_equal(cmap2, cmap)
+    cmap = AffineTransform(in_cs, out_cs, np.eye(4))
+    class AT2(AffineTransform): pass
+    cmap2 = AT2(in_cs, out_cs, np.eye(4))
+    assert_equal(cmap, cmap2)
+    assert_equal(cmap2, cmap)
+
+
 def test_cmap_coord_types():
     # Check that we can use full range of coordinate system types.  The inverse
     # of an AffineTransform should generate coordinates in the input coordinate
