moving to make_node implementation

this fixes the issue and theano automatically does the right broadcasting.

Author: michaelosthege

pymc3/distributions/dist_math.py

@@ -317,12 +317,14 @@ class SplineWrapper(theano.Op):
     """
 
     __props__ = ('spline',)
-    itypes = [tt.dscalar]
-    otypes = [tt.dscalar]
 
     def __init__(self, spline):
         self.spline = spline
 
+    def make_node(self, x):
+        x = tt.as_tensor_variable(x)
+        return tt.Apply(self, [x], [x.type()])
+
     @property
     def grad_op(self):
         if not hasattr(self, '_grad_op'):