give name to output variable and a better string reprensentation for MaxAndArgMax

theano/tensor/basic.py

@@ -638,7 +638,8 @@ class TensorType(Type):
 # Easy constructors
 
 def tensor(*args, **kwargs):
-    return TensorType(*args, **kwargs).make_variable()
+    name = kwargs.get('name',None)
+    return TensorType(*args, **kwargs).make_variable(name=name)
 
 def _multi(*fns):
     def f2(f, *names):
@@ -1307,8 +1308,8 @@ class MaxAndArgmax(Op):
         axis = _as_tensor_variable(axis)
         inputs = [x, axis]
         broadcastable = [False] * (x.type.ndim - 1) #TODO: be less conservative
-        outputs = [tensor(x.type.dtype, broadcastable), 
-                   tensor('int32', broadcastable)]
+        outputs = [tensor(x.type.dtype, broadcastable,name='max'), 
+                   tensor('int32', broadcastable,name='argmax')]
         return Apply(self, inputs, outputs)
     def perform(self, node, (x, axis), (max, max_idx)):
         max[0] = numpy.asarray(numpy.max(x, axis))
@@ -1336,6 +1337,8 @@ class MaxAndArgmax(Op):
           xmax_pad = shape_padright(xmax)
         g_x = eq(xmax_pad, x) * g_max_pad
         return g_x, None
+    def __str__(self):
+      return self.__class__.__name__
 
 _max_and_argmax = MaxAndArgmax()
 @_redefine_asRoutine(_max_and_argmax)