def test_layers_view():
    X = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
    L = np.array([[10, 11, 12], [13, 14, 15], [16, 17, 18]])
    real_adata = ad.AnnData(X)
    real_adata.layers["L"] = L
    view_adata = real_adata[1:, 1:]
    real_hash = joblib.hash(real_adata)
    view_hash = joblib.hash(view_adata)

    assert view_adata.is_view

    with pytest.raises(ValueError):
        view_adata.layers["L2"] = L + 2

    assert view_adata.is_view  # Failing to set layer item makes adata not view
    assert real_hash == joblib.hash(real_adata)
    assert view_hash == joblib.hash(view_adata)

    view_adata.layers["L2"] = L[1:, 1:] + 2

    assert not view_adata.is_view
    assert real_hash == joblib.hash(real_adata)
    assert view_hash != joblib.hash(view_adata)
def test_fresnel_coefficients():
    assert all(ae(i, j, 5) for i, j in zip(
        fresnel_coefficients(0.5, 1, 1.33),
        [0.11163, -0.17138, 0.83581, 0.82862]))
    assert all(ae(i, j, 5) for i, j in zip(
        fresnel_coefficients(0.5, 1.33, 1),
        [-0.07726, 0.20482, 1.22724, 1.20482]))
    m1 = Medium('m1')
    m2 = Medium('m2', n=2)
    assert all(ae(i, j, 5) for i, j in zip(
        fresnel_coefficients(0.3, m1, m2),
        [0.31784, -0.34865, 0.65892, 0.65135]))
    ans = [[-0.23563, -0.97184], [0.81648, -0.57738]]
    got = fresnel_coefficients(0.6, m2, m1)
    for i, j in zip(got, ans):
        for a, b in zip(i.as_real_imag(), j):
            assert ae(a, b, 5)