factory.py 文件源码

def _random_vec(sites, ldim, randstate=None, dtype=np.complex_):
    """Returns a random complex vector (normalized to ||x||_2 = 1) of shape
    (ldim,) * sites, i.e. a pure state with local dimension `ldim` living on
    `sites` sites.

    :param sites: Number of local sites
    :param ldim: Local ldimension
    :param randstate: numpy.random.RandomState instance or None
    :returns: numpy.ndarray of shape (ldim,) * sites

    >>> psi = _random_vec(5, 2); psi.shape
    (2, 2, 2, 2, 2)
    >>> np.abs(np.vdot(psi, psi) - 1) < 1e-6
    True
    """
    shape = (ldim, ) * sites
    psi = _randfuncs[dtype](shape, randstate=randstate)
    psi /= np.linalg.norm(psi)
    return psi