def testDiagonal (self):
"Test the diagonal function."
b=MA.array([[1,2,3,4],[5,6,7,8]]*2)
assert eq(MA.diagonal(b), [1,6,3,8])
assert eq(MA.diagonal(b, -1), [5,2,7])
c = MA.array([b,b])
assert eq(MA.diagonal(c,1), [[2,7,4], [2,7,4]])
