Gist showing an erroneous result from tensor.dot when one of the operand is zero.

tensor_dot.py

import numpy as np
import theano
import theano.tensor as T
print "Version:", theano.version.version

print "=Theano="
A = T.zeros((2,10))
B = T.zeros((30, 10))

print "Shape of A:", A.eval().shape
print "Shape of B:", B.eval().shape
print "AB =\n", T.dot(A,B).eval()
print "Shape of AB:", T.dot(A,B).eval().shape


print "=Numpy="
A = np.zeros((2,10))
B = np.zeros((30, 10))

print "Shape of A:", A.shape
print "Shape of B:", B.shape
print "AB =", np.dot(A,B)
print "Shape of AB:", np.dot(A,B).shape