combination of two transformations of the same type result in this type again

2026-07-29 11:26:57 +08:00 · 2012-07-22 16:38:25 +02:00
parent 87c57770ba
commit be6bb0c809
1 changed files with 7 additions and 1 deletions
@@ -176,7 +176,13 @@ class ProjectiveTransform(GeometricTransform):

        """
        if isinstance(other, ProjectiveTransform):
-            return ProjectiveTransform(np.dot(other._matrix, self._matrix))
+            # combination of the same types result in a transformation of this
+            # type again, otherwise use general projective transformation
+            if type(self) == type(other):
+                tform = self.__class__
+            else:
+                tform = ProjectiveTransform
+            return tform(other._matrix.dot(self._matrix))
        else:
            raise TypeError("Cannot combine transformations of differing "
                            "types.")