mpsmpo_test.py 文件源码

def test_pmps_to_mpo(nr_sites, local_dim, rank, rgen):
    if (nr_sites % 2) != 0:
        return
    nr_sites = nr_sites // 2
    pmps = factory.random_mpa(nr_sites, (local_dim, local_dim), rank,
                              dtype=np.complex_, randstate=rgen)
    rho_mp = mm.pmps_to_mpo(pmps).to_array_global()

    # Local form is what we will use: One system site, one ancilla site, etc
    purification = pmps.to_array()
    # Convert to a density matrix
    purification = np.outer(purification, purification.conj())
    purification = purification.reshape((local_dim,) * (2 * 2 * nr_sites))
    # Trace out the ancilla sites
    traceout = tuple(range(1, 2 * nr_sites, 2))
    rho_np = utils.partial_trace(purification, traceout)

    # Here, we need global form
    assert_array_almost_equal(rho_mp, rho_np)