_testing.py 文件源码

def random_lowrank(rows, cols, rank, randstate=np.random, dtype=np.float_):
    """Returns a random lowrank matrix of given shape and dtype"""
    if dtype == np.float_:
        A = randstate.randn(rows, rank)
        B = randstate.randn(cols, rank)
    elif dtype == np.complex_:
        A = randstate.randn(rows, rank) + 1.j * randstate.randn(rows, rank)
        B = randstate.randn(cols, rank) + 1.j * randstate.randn(cols, rank)
    else:
        raise ValueError("{} is not a valid dtype".format(dtype))

    C = A.dot(B.conj().T)
    return C / np.linalg.norm(C)