Function test_bem_solution

mne/tests/test_bem.py:256–324

Test making a BEM solution from Python and OpenMEEG with I/O.

(tmp_path, cond, fname)

    ],
)
def test_bem_solution(tmp_path, cond, fname):
    """Test making a BEM solution from Python and OpenMEEG with I/O."""
    pytest.importorskip("nibabel")
    # test degenerate conditions
    surf = read_bem_surfaces(fname_bem_1)[0]
    with pytest.raises(RuntimeError, match="2 or less"):
        _ico_downsample(surf, 10)
    s_bad = dict(tris=surf["tris"][1:], ntri=surf["ntri"] - 1, rr=surf["rr"])
    with pytest.raises(RuntimeError, match="Cannot decimate.*isomorphic"):
        _ico_downsample(s_bad, 1)
    s_bad = dict(
        tris=surf["tris"].copy(), ntri=surf["ntri"], rr=surf["rr"]
    )  # bad triangulation
    s_bad["tris"][0] = [0, 0, 0]
    with pytest.raises(RuntimeError, match="ordering is wrong"):
        _ico_downsample(s_bad, 1)
    s_bad["id"] = 1
    with pytest.raises(RuntimeError, match="is not complete"):
        _assert_complete_surface(s_bad)
    s_bad = dict(tris=surf["tris"], ntri=surf["ntri"], rr=surf["rr"].copy())
    s_bad["rr"][0] = 0.0
    with pytest.raises(RuntimeError, match="No matching vertex"):
        _get_ico_map(surf, s_bad)

    surfs = read_bem_surfaces(fname_bem_3)
    with pytest.raises(RuntimeError, match="is not completely inside"):
        _assert_inside(surfs[0], surfs[1])  # outside
    surfs[0]["id"] = 100  # bad surfs
    with pytest.raises(RuntimeError, match="bad surface id"):
        _order_surfaces(surfs)
    surfs[1]["rr"] /= 1000.0
    with pytest.raises(RuntimeError, match="seem too small"):
        _check_surface_size(surfs[1])

    # actually test functionality
    fname_temp = tmp_path / "temp-bem-sol.fif"
    # use a model and solution made in Python
    for model_type in ("python", "c"):
        if model_type == "python":
            model = make_bem_model(
                "sample", conductivity=cond, ico=2, subjects_dir=subjects_dir
            )
        else:
            model = fname_bem_1 if len(cond) == 1 else fname_bem_3
    solution = make_bem_solution(model, verbose=True)
    assert solution["solver"] == "mne"
    solution_c = read_bem_solution(fname)
    assert solution_c["solver"] == "mne"
    _compare_bem_solutions(solution, solution_c)
    write_bem_solution(fname_temp, solution)
    solution_read = read_bem_solution(fname_temp)
    assert solution["solver"] == solution_c["solver"] == "mne"
    assert solution_read["solver"] == "mne"
    _compare_bem_solutions(solution, solution_c)
    _compare_bem_solutions(solution_read, solution_c)
    # OpenMEEG
    pytest.importorskip(
        "openmeeg",