#NEWLINE# def vector_product( v0 , v1 , axis = 0 ) : #NEWLINE# #INDENT# 'Return vector perpendicular to vectors.\n\n    >>> v = vector_product([2, 0, 0], [0, 3, 0])\n    >>> numpy.allclose(v, [0, 0, 6])\n    True\n    >>> v0 = [[2, 0, 0, 2], [0, 2, 0, 2], [0, 0, 2, 2]]\n    >>> v1 = [[3], [0], [0]]\n    >>> v = vector_product(v0, v1)\n    >>> numpy.allclose(v, [[0, 0, 0, 0], [0, 0, 6, 6], [0, -6, 0, -6]])\n    True\n    >>> v0 = [[2, 0, 0], [2, 0, 0], [0, 2, 0], [2, 0, 0]]\n    >>> v1 = [[0, 3, 0], [0, 0, 3], [0, 0, 3], [3, 3, 3]]\n    >>> v = vector_product(v0, v1, axis=1)\n    >>> numpy.allclose(v, [[0, 0, 6], [0, -6, 0], [6, 0, 0], [0, -6, 6]])\n    True\n\n    ' #NEWLINE# return numpy . cross ( v0 , v1 , axis = axis )