Add x.ones_like() as x.zeros_like()

theano/gradient.py

@@ -1339,7 +1339,7 @@ def _float_ones_like(x):
     if dtype not in tensor.float_dtypes:
         dtype = theano.config.floatX
 
-    return tensor.ones_like(x, dtype=dtype)
+    return x.ones_like(dtype=dtype)
 
 
 class numeric_grad(object):

theano/tensor/var.py

@@ -731,6 +731,9 @@ class _tensor_py_operators(object):
     def zeros_like(model, dtype=None):
         return theano.tensor.basic.zeros_like(model, dtype=dtype)
 
+    def ones_like(model, dtype=None):
+        return theano.tensor.basic.ones_like(model, dtype=dtype)
+
     def cumsum(self, axis=None):
         return theano.tensor.extra_ops.cumsum(self, axis)