def numpy_array_from_list_or_numpy_array(vectors):
    """
    Returns numpy array representation of argument.

    Argument maybe numpy array (input is returned)
    or a list of numpy vectors.
    """
    # If vectors is not a numpy matrix, create one
    if not isinstance(vectors, numpy.ndarray):
        V = numpy.zeros((vectors[0].shape[0], len(vectors)))
        for index in range(len(vectors)):
            vector = vectors[index]
            V[:, index] = vector
        return V

    return vectors
Returns numpy array representation of argument.

    Argument maybe numpy array (input is returned)
    or a list of numpy vectors.