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 winding_factors(wdg, n=8, ax=0):
    """plot winding factors"""
    ax = plt.gca()
    ax.set_title(f'Winding factors Q={wdg.Q}, p={wdg.p}, q={round(wdg.q,4)}')
    ax.grid(True)
    order, kwp, kwd, kw = np.array([(n, k1, k2, k3)
                                    for n, k1, k2, k3 in zip(wdg.kw_order(n),
                                                             wdg.kwp(n),
                                                             wdg.kwd(n),
                                                             wdg.kw(n))]).T
    try:
        markerline1, stemlines1, _ = ax.stem(order-1, kwp, 'C1:', basefmt=" ",
                                             markerfmt='C1.',
                                             use_line_collection=True, label='Pitch')
        markerline2, stemlines2, _ = ax.stem(order+1, kwd, 'C2:', basefmt=" ",
                                             markerfmt='C2.',
                                             use_line_collection=True, label='Distribution')
        markerline3, stemlines3, _ = ax.stem(order, kw, 'C0-', basefmt=" ",
                                             markerfmt='C0o',
                                             use_line_collection=True, label='Total')
        ax.set_xticks(order)
        ax.legend()
    except ValueError:  # empty sequence
        pass