factory.py 文件源码

def _random_op(sites, ldim, hermitian=False, normalized=False, randstate=None,
               dtype=np.complex_):
    """Returns a random operator  of shape (ldim,ldim) * sites with local
    dimension `ldim` living on `sites` sites in global form.

    :param sites: Number of local sites
    :param ldim: Local ldimension
    :param hermitian: Return only the hermitian part (default False)
    :param normalized: Normalize to Frobenius norm=1 (default False)
    :param randstate: numpy.random.RandomState instance or None
    :returns: numpy.ndarray of shape (ldim,ldim) * sites

    >>> A = _random_op(3, 2); A.shape
    (2, 2, 2, 2, 2, 2)
    """
    op = _randfuncs[dtype]((ldim**sites,) * 2, randstate=randstate)
    if hermitian:
        op += np.transpose(op).conj()
    if normalized:
        op /= np.linalg.norm(op)
    return op.reshape((ldim,) * 2 * sites)