fixed the gradient of set_subtensor

Before only the gradient of inc_subtensor was ok ( and it also was the only one checked)

fixed the gradient of set_subtensor
74863ee8 · Razvan Pascanu · 106b8308 · 74863ee8
--- a/theano/tensor/basic.py
+++ b/theano/tensor/basic.py
@@ -3708,7 +3708,12 @@ class IncSubtensor(Op):
        x, y = inputs[:2]
        idx_list = inputs[2:]

-        gx = g_output
+        if self.set_instead_of_inc:
+            gx = set_subtensor(
+                Subtensor(idx_list=self.idx_list)(g_output,*idx_list),
+                zeros_like(y))
+        else:
+            gx = g_output
        gy = Subtensor(idx_list = self.idx_list)(g_output, *idx_list)

        return [gx, gy] + [None]*len(idx_list)