Merge pull request #2750 from SinaHonari/issue2500

theano/compile/ops.py

@@ -385,8 +385,8 @@ class Shape_i(gof.Op):
         return [()]
 
     def grad(self, inp, grads):
-        return [None]
-
+        return [theano.gradient.grad_not_implemented(op=self, x_pos=0, x=inp[0],
+                comment="No gradient for the shape of a matrix is implemented.")]
 
 def shape_i(var, i, fgraph=None):
     """Equivalent of var.shape[i], but apply if possible the shape

theano/sandbox/scan_module/scan_op.py

@@ -341,12 +341,6 @@ class ScanOp(PureOp):
         rval.lazy = False
         return rval
 
-    def grad(self, args, g_outs):
-        pass
-
-    def R_op(self, inputs, eval_points):
-        pass
-
 
 @theano.compile.profilemode.register_profiler_printer
 def profile_printer(fct_name, compile_time, fct_call_time, fct_call,

theano/scalar/basic.py

@@ -1155,8 +1155,22 @@ class InRange(LogicalComparison):
         return ("%(z)s = %(x)s %(cmp1)s %(low)s &&"
                 " %(x)s %(cmp2)s %(hi)s;" % locals())
 
+    def get_grad(self, elem):
+        if elem.type in complex_types:
+            msg = "No gradient implemented for complex numbers in\
+                                 class scalar.basic.InRange"
+            raise NotImplementedError(msg)
+        elif elem.type in discrete_types:
+            return elem.zeros_like().astype(theano.config.floatX)
+        else:
+            return elem.zeros_like()
+
     def grad(self, (x, low, hi), (gz, )):
-        return None, None, None
+        grads = []
+        for elem in [x, low, hi]:
+            grads.append(get_grad(elem))
+        return grads
+
 inopenrange = InRange(True, True)
 inclosedrange = InRange(False, False)
 
@@ -2928,7 +2942,8 @@ class Imag(UnaryScalarOp):
         elif x.type in float_types:
             return [second(x, 0)]
         else:
-            return [None]
+            return [x.zeros_like(dtype=theano.config.floatX)]
+
 imag = Imag(real_out, name='imag')
 
 
@@ -2959,7 +2974,7 @@ class Angle(UnaryScalarOp):
         elif c in float_types:
             return [cast(second(x, 0), x.type.dtype)]
         else:
-            return [None]
+            return [c.zeros_like(dtype=theano.config.floatX)]
 
 angle = Angle(specific_out(float64), name='angle')
 

theano/sparse/basic.py

@@ -832,12 +832,24 @@ class Cast(gof.op.Op):
         out[0] = x.astype(self.out_type)
 
     def grad(self, inputs, outputs_gradients):
-        if inputs[0].dtype in tensor.continuous_dtypes:
-            gz = outputs_gradients[0]
-            return [Cast(inputs[0].dtype)(gz)]
-        else:
-            return [None]
+        gz = outputs_gradients[0]
 
+        if gz.dtype in complex_dtypes:
+            raise NotImplementedError("grad not implemented for complex types")
+        if inputs[0].dtype in complex_dtypes:
+            raise NotImplementedError("grad not implemented for complex types")
+
+        if gz.dtype in discrete_dtypes:
+            if inputs[0].dtype in discrete_dtypes:
+                return [inputs[0].zeros_like(dtype=theano.config.floatX)]
+            else:
+                return [inputs[0].zeros_like()]
+        else:
+            if inputs[0].dtype in discrete_dtypes:
+                return [gz]
+            else:
+                return [Cast(inputs[0].dtype)(gz)]
+ 
     def infer_shape(self, node, ins_shapes):
         return ins_shapes
 
@@ -1647,8 +1659,7 @@ class SpSum(gof.op.Op):
 
     def grad(self, (x,), (gz,)):
         if x.dtype not in continuous_dtypes:
-            return [None]
-
+            return [x.zeros_like(dtype=theano.config.floatX)]
         if self.structured:
             if self.axis is None:
                 r = gz * theano.sparse.sp_ones_like(x)

theano/sparse/sandbox/sp2.py

 import numpy
+import theano
 import scipy.sparse
 
 from theano import gof, tensor
@@ -79,7 +80,10 @@ class Poisson(gof.op.Op):
         out[0].eliminate_zeros()
 
     def grad(self, inputs, outputs_gradients):
-        return [None]
+        comment = "No gradient exists for class Poisson in\
+                   theano/sparse/sandbox/sp2.py"
+        return [theano.gradient.grad_undefined(op=self, x_pos=0, x=inputs[0],
+                                               comment=comment)]
 
     def infer_shape(self, node, ins_shapes):
         return ins_shapes
@@ -131,8 +135,19 @@ class Binomial(gof.op.Op):
         csx_matrix = getattr(scipy.sparse, self.format + '_matrix')
         out[0] = csx_matrix(binomial, dtype=self.dtype)
 
+    def connection_pattern(self, node):
+        return [[True], [True], [False]]
+
     def grad(self, (n, p, shape, ), (gz,)):
-        return None, None, None
+        comment_n = "No gradient exists for the number of samples in class\
+                     Binomial of theano/sparse/sandbox/sp2.py"
+        comment_p = "No gradient exists for the prob of success in class\
+                     Binomial of theano/sparse/sandbox/sp2.py"
+        return [theano.gradient.grad_undefined(op=self, x_pos=0, x=n,
+                                               comment=comment_n),
+                theano.gradient.grad_undefined(op=self, x_pos=1, x=p,
+                                               comment=comment_p),
+                theano.gradient.disconnected_type()]
 
     def infer_shape(self, node, ins_shapes):
         return [(node.inputs[2][0], node.inputs[2][1])]
@@ -202,7 +217,14 @@ class Multinomial(gof.op.Op):
                 out[0].data[k:l] = numpy.random.multinomial(n[i], p.data[k:l])
 
     def grad(self, inputs, outputs_gradients):
-        return [None, None]
+        comment_n = "No gradient exists for the number of samples in class\
+                     Multinomial of theano/sparse/sandbox/sp2.py"
+        comment_p = "No gradient exists for the prob of success in class\
+                     Multinomial of theano/sparse/sandbox/sp2.py"
+        return [theano.gradient.grad_undefined(op=self, x_pos=0, x=inputs[0],
+                                               comment=comment_n),
+                theano.gradient.grad_undefined(op=self, x_pos=1, x=inputs[1],
+                                               comment=comment_p)]
 
     def infer_shape(self, node, ins_shapes):
         return [ins_shapes[1]]