povm_test.py 文件源码

def test_povm_ic_mpa(nr_sites, local_dim, rank, rgen):
    # Check that the tensor product of the PauliGen POVM is IC.
    paulis = povm.pauli_povm(local_dim)
    inv_map = mp_from_array_repeat(paulis.linear_inversion_map, nr_sites)
    probab_map = mp_from_array_repeat(paulis.probability_map, nr_sites)
    reconstruction_map = mp.dot(inv_map, probab_map)

    eye = factory.eye(nr_sites, local_dim**2)
    assert mp.norm(reconstruction_map - eye) < 1e-5

    # Check linear inversion for a particular example MPA.
    # Linear inversion works for arbitrary matrices, not only for states,
    # so we test it for an arbitrary MPA.
    # Normalize, otherwise the absolute error check below will not work.
    mpa = factory.random_mpa(nr_sites, local_dim**2, rank,
                             dtype=np.complex_, randstate=rgen, normalized=True)
    probabs = mp.dot(probab_map, mpa)
    recons = mp.dot(inv_map, probabs)
    assert mp.norm(recons - mpa) < 1e-6