Function test_average_forward_solution

mne/forward/tests/test_forward.py:437–482

Test averaging forward solutions.

(tmp_path)

@testing.requires_testing_data
@requires_mne
def test_average_forward_solution(tmp_path):
    """Test averaging forward solutions."""
    fwd = read_forward_solution(fname_meeg)
    # input not a list
    pytest.raises(TypeError, average_forward_solutions, 1)
    # list is too short
    pytest.raises(ValueError, average_forward_solutions, [])
    # negative weights
    pytest.raises(ValueError, average_forward_solutions, [fwd, fwd], [-1, 0])
    # all zero weights
    pytest.raises(ValueError, average_forward_solutions, [fwd, fwd], [0, 0])
    # weights not same length
    pytest.raises(ValueError, average_forward_solutions, [fwd, fwd], [0, 0, 0])
    # list does not only have all dict()
    pytest.raises(TypeError, average_forward_solutions, [1, fwd])

    # try an easy case
    fwd_copy = average_forward_solutions([fwd])
    assert isinstance(fwd_copy, Forward)
    assert_array_equal(fwd["sol"]["data"], fwd_copy["sol"]["data"])

    # modify a fwd solution, save it, use MNE to average with old one
    fwd_copy["sol"]["data"] *= 0.5
    fname_copy = str(tmp_path / "copy-fwd.fif")
    write_forward_solution(fname_copy, fwd_copy, overwrite=True)
    cmd = (
        "mne_average_forward_solutions",
        "--fwd",
        fname_meeg,
        "--fwd",
        fname_copy,
        "--out",
        fname_copy,
    )
    run_subprocess(cmd)

    # now let's actually do it, with one filename and one fwd
    fwd_ave = average_forward_solutions([fwd, fwd_copy])
    assert_array_equal(0.75 * fwd["sol"]["data"], fwd_ave["sol"]["data"])
    # fwd_ave_mne = read_forward_solution(fname_copy)
    # assert_array_equal(fwd_ave_mne['sol']['data'], fwd_ave['sol']['data'])

    # with gradient
    fwd = read_forward_solution(fname_meeg_grad)
    fwd_ave = average_forward_solutions([fwd, fwd])
    assert_forward_allclose(fwd, fwd_ave)


@testing.requires_testing_data