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 __init__(self, root, split="train", transforms=None):
        super().__init__(root=root, transforms=transforms)

        verify_str_arg(split, "split", valid_values=("train", "val"))

        root = Path(root) / "FlyingChairs"
        images = sorted(glob(str(root / "data" / "*.ppm")))
        flows = sorted(glob(str(root / "data" / "*.flo")))

        split_file_name = "FlyingChairs_train_val.txt"

        if not os.path.exists(root / split_file_name):
            raise FileNotFoundError(
                "The FlyingChairs_train_val.txt file was not found - please download it from the dataset page (see docstring)."
            )

        split_list = np.loadtxt(str(root / split_file_name), dtype=np.int32)
        for i in range(len(flows)):
            split_id = split_list[i]
            if (split == "train" and split_id == 1) or (split == "val" and split_id == 2):
                self._flow_list += [flows[i]]
                self._image_list += [[images[2 * i], images[2 * i + 1]]]