def vectors(vs):
    """
    For a list of vectors of the form [x0, ..., xn, y0, ..., yn, z0, ..., zn]
    this will return a list of vectors with the shape
    [[x0, y0, z0], ..., [xn, yn, zn]].

    """
    number_of_nodes = len(vs) // 3
    return vs.view().reshape((number_of_nodes, -1), order="F")