Merge pull request #547 from ANTsX/rightside-ops

rightside ops

ants/core/ants_image.py

@@ -446,6 +446,17 @@ def __add__(self, other):
         new_array = this_array + other
         return self.new_image_like(new_array)
 
+    def __radd__(self, other):
+        this_array = self.numpy()
+
+        if isinstance(other, ANTsImage):
+            if not image_physical_space_consistency(self, other):
+                raise ValueError('images do not occupy same physical space')
+            other = other.numpy()
+
+        new_array = other + this_array
+        return self.new_image_like(new_array)
+
     def __sub__(self, other):
         this_array = self.numpy()
 
@@ -457,6 +468,17 @@ def __sub__(self, other):
         new_array = this_array - other
         return self.new_image_like(new_array)
 
+    def __rsub__(self, other):
+        this_array = self.numpy()
+
+        if isinstance(other, ANTsImage):
+            if not image_physical_space_consistency(self, other):
+                raise ValueError('images do not occupy same physical space')
+            other = other.numpy()
+
+        new_array = other - this_array
+        return self.new_image_like(new_array)
+
     def __mul__(self, other):
         this_array = self.numpy()
 
@@ -468,6 +490,17 @@ def __mul__(self, other):
         new_array = this_array * other
         return self.new_image_like(new_array)
 
+    def __rmul__(self, other):
+        this_array = self.numpy()
+
+        if isinstance(other, ANTsImage):
+            if not image_physical_space_consistency(self, other):
+                raise ValueError('images do not occupy same physical space')
+            other = other.numpy()
+
+        new_array = other * this_array
+        return self.new_image_like(new_array)
+
     def __truediv__(self, other):
         this_array = self.numpy()
 

tests/test_core_ants_image.py

@@ -232,6 +232,25 @@ def test__add__(self):
                 img2.set_spacing([2.31]*img.dimension)
                 img3 = img + img2
 
+    def test__radd__(self):
+        #self.setUp()
+        for img in self.imgs:
+            # op on constant
+            img2 = 6.9 + img 
+            self.assertTrue(ants.image_physical_space_consistency(img, img2))
+            nptest.assert_allclose(img2.numpy(), img.numpy() + 6.9)
+
+            # op on another image
+            img2 = img + img.clone()
+            self.assertTrue(ants.image_physical_space_consistency(img, img2))
+            nptest.assert_allclose(img2.numpy(), img.numpy()+img.numpy())
+
+            with self.assertRaises(Exception):
+                # different physical space
+                img2 = img.clone()
+                img2.set_spacing([2.31]*img.dimension)
+                img3 = img + img2
+
     def test__sub__(self):
         #self.setUp()
         for img in self.imgs:
@@ -251,6 +270,25 @@ def test__sub__(self):
                 img2.set_spacing([2.31]*img.dimension)
                 img3 = img - img2
 
+    def test__rsub__(self):
+        #self.setUp()
+        for img in self.imgs:
+            # op on constant
+            img2 = 6.9 - img
+            self.assertTrue(ants.image_physical_space_consistency(img, img2))
+            nptest.assert_allclose(img2.numpy(), 6.9 - img.numpy())
+
+            # op on another image
+            img2 = img - img.clone()
+            self.assertTrue(ants.image_physical_space_consistency(img, img2))
+            nptest.assert_allclose(img2.numpy(), img.numpy()-img.numpy())
+
+            with self.assertRaises(Exception):
+                # different physical space
+                img2 = img.clone()
+                img2.set_spacing([2.31]*img.dimension)
+                img3 = img - img2
+
     def test__mul__(self):
         #self.setUp()
         for img in self.imgs:
@@ -270,6 +308,25 @@ def test__mul__(self):
                 img2.set_spacing([2.31]*img.dimension)
                 img3 = img * img2
 
+    def test__rmul__(self):
+        #self.setUp()
+        for img in self.imgs:
+            # op on constant
+            img2 = 6.9 * img
+            self.assertTrue(ants.image_physical_space_consistency(img, img2))
+            nptest.assert_allclose(img2.numpy(), 6.9*img.numpy())
+
+            # op on another image
+            img2 = img * img.clone()
+            self.assertTrue(ants.image_physical_space_consistency(img, img2))
+            nptest.assert_allclose(img2.numpy(), img.numpy()*img.numpy())
+
+            with self.assertRaises(Exception):
+                # different physical space
+                img2 = img.clone()
+                img2.set_spacing([2.31]*img.dimension)
+                img3 = img * img2
+
     def test__div__(self):
         #self.setUp()
         for img in self.imgs: