made verbose exception for elemwise perform

theano/tensor/elemwise.py

@@ -8,8 +8,10 @@ from theano import gof
 from theano.gof import Apply, Op
 from theano import scalar
 from theano.scalar import Scalar
-from theano.printing import pprint
+from theano.printing import min_informative_str, pprint
 from theano.gof.python25 import all, any
+config = theano.config
+
 
 
 # tensor depends on elemwise to provide definitions for several ops
@@ -685,8 +687,15 @@ class Elemwise(Op):
                             msg2 += [str(d)]
                     msg.append('(%s)' % ", ".join(msg2))
 
-                raise ValueError('Dimension mismatch; shapes are %s' %
-                        ', '.join(msg))
+                base_exc_str = 'Dimension mismatch; shapes are %s' % (', '.join(msg))
+                if config.exception_verbosity == 'high':
+                    msg_chunks = [ base_exc_str ]
+                    for i, ipt in enumerate(node.inputs):
+                        msg_chunks.append('input %d: %s' % (i, min_informative_str(ipt)))
+                    raise ValueError('\n'.join(msg_chunks))
+                else:
+                    raise ValueError(base_exc_str)
+
                                  #', '.join('(%s)' % ', '.join(msg)))
                 #backport
                 #raise ValueError('Dimension mismatch; shapes are %s' %