def test_negative_scalar_index(adata, index: int, obs: bool):
    pos_index = index + (adata.n_obs if obs else adata.n_vars)

    if obs:
        adata_pos_subset = adata[pos_index]
        adata_neg_subset = adata[index]
    else:
        adata_pos_subset = adata[:, pos_index]
        adata_neg_subset = adata[:, index]

    np.testing.assert_array_equal(
        adata_pos_subset.obs_names, adata_neg_subset.obs_names
    )
    np.testing.assert_array_equal(
        adata_pos_subset.var_names, adata_neg_subset.var_names
    )
def test_ccode_Indexed_without_looking_for_contraction():
    len_y = 5
    y = IndexedBase('y', shape=(len_y,))
    x = IndexedBase('x', shape=(len_y,))
    Dy = IndexedBase('Dy', shape=(len_y-1,))
    i = Idx('i', len_y-1)
    e=Eq(Dy[i], (y[i+1]-y[i])/(x[i+1]-x[i]))
    code0 = ccode(e.rhs, assign_to=e.lhs, contract=False)
    assert code0 == 'Dy[i] = (y[%s] - y[i])/(x[%s] - x[i]);' % (i + 1, i + 1)