def test_set_subset_obsm(adata, subset_func):
    init_hash = joblib.hash(adata)
    orig_obsm_val = adata.obsm["o"].copy()

    while True:
        subset_idx = slice_subset(adata.obs_names)
        if len(adata[subset_idx, :]) > 2:
            break
    subset = adata[subset_idx, :]

    internal_idx = _normalize_index(
        subset_func(np.arange(subset.obsm["o"].shape[0])), subset.obs_names
    )

    assert subset.is_view
    subset.obsm["o"][internal_idx] = 1
    assert not subset.is_view
    assert np.all(adata.obsm["o"] == orig_obsm_val)

    assert init_hash == joblib.hash(adata)
def test_lens_formula():
    u, v, f = symbols('u, v, f')
    assert lens_formula(focal_length=f, u=u) == f*u/(f + u)
    assert lens_formula(focal_length=f, v=v) == f*v/(f - v)
    assert lens_formula(u=u, v=v) == u*v/(u - v)
    assert lens_formula(u=oo, v=v) == v
    assert lens_formula(u=oo, v=oo) is oo
    assert lens_formula(focal_length=oo, u=u) == u
    assert lens_formula(u=u, v=oo) == -u
    assert lens_formula(focal_length=oo, v=oo) is -oo
    assert lens_formula(focal_length=oo, v=v) == v
    assert lens_formula(focal_length=f, v=oo) == -f
    assert lens_formula(focal_length=oo, u=oo) is oo
    assert lens_formula(focal_length=oo, u=u) == u
    assert lens_formula(focal_length=f, u=oo) == f
    raises(ValueError, lambda: lens_formula(focal_length=f, u=u, v=v))