bugfix

test/forward.json

@@ -6,5 +6,21 @@
     "input": [[2, 0, 1, 4, 3], [0, 2, 1, 3, 4]],
     "dim": 1,
     "expected": [[0, 0, 4, 3, 3, 0], [2, 4, 4, 0, 0, 0]]
+  },
+  {
+    "name": "sub",
+    "output": [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0]],
+    "index": [[4, 5, 4, 2, 3], [0, 0, 2, 2, 1]],
+    "input": [[2, 0, 1, 4, 3], [0, 2, 1, 3, 4]],
+    "dim": 1,
+    "expected": [[0, 0, -4, -3, -3, 0], [-2, -4, -4, 0, 0, 0]]
+  },
+  {
+    "name": "mul",
+    "output": [[1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 1, 1]],
+    "index": [[4, 5, 4, 2, 3], [0, 0, 2, 2, 1]],
+    "input": [[2, 0, 1, 4, 3], [0, 2, 1, 3, 4]],
+    "dim": 1,
+    "expected": [[1, 1, 4, 3, 2, 0], [0, 4, 3, 1, 1, 1]]
   }
 ]

torch_scatter/functions/sub.py

@@ -51,7 +51,7 @@ def scatter_sub_(output, index, input, dim=0):
        -2 -4 -4  0  0  0
        [torch.FloatTensor of size 2x6]
     """
-    return output.scatter_add_(dim, index, -input)
+    return output.scatter_add_(dim, index, -1 * input)
 
 
 def scatter_sub(index, input, dim=0, size=None, fill_value=0):