def test_view_of_view(matrix_type, subset_func, subset_func2):
    adata = gen_adata((30, 15), X_type=matrix_type)
    adata.raw = adata
    if subset_func is single_subset:
        pytest.xfail("Other subset generating functions have trouble with this")
    var_s1 = subset_func(adata.var_names, min_size=4)
    var_view1 = adata[:, var_s1]
    var_s2 = subset_func2(var_view1.var_names)
    var_view2 = var_view1[:, var_s2]
    assert var_view2._adata_ref is adata
    obs_s1 = subset_func(adata.obs_names, min_size=4)
    obs_view1 = adata[obs_s1, :]
    obs_s2 = subset_func2(obs_view1.obs_names)
    assert adata[obs_s1, :][:, var_s1][obs_s2, :]._adata_ref is adata

    view_of_actual_copy = adata[:, var_s1].copy()[obs_s1, :].copy()[:, var_s2].copy()

    view_of_view_copy = adata[:, var_s1][obs_s1, :][:, var_s2].copy()

    assert_equal(view_of_actual_copy, view_of_view_copy, exact=True)
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