@testing.requires_testing_data
@requires_version('scipy', '0.11')
def test_add_source_space_distances_limited():
    """Test adding distances to source space with a dist_limit"""
    tempdir = _TempDir()
    src = read_source_spaces(fname)
    src_new = read_source_spaces(fname)
    del src_new[0]['dist']
    del src_new[1]['dist']
    n_do = 200  # limit this for speed
    src_new[0]['vertno'] = src_new[0]['vertno'][:n_do].copy()
    src_new[1]['vertno'] = src_new[1]['vertno'][:n_do].copy()
    out_name = op.join(tempdir, 'temp-src.fif')
    try:
        add_source_space_distances(src_new, dist_limit=0.007)
    except __HOLE__:  # what we throw when scipy version is wrong
        raise SkipTest('dist_limit requires scipy > 0.13')
    write_source_spaces(out_name, src_new)
    src_new = read_source_spaces(out_name)

    for so, sn in zip(src, src_new):
        assert_array_equal(so['dist_limit'], np.array([-0.007], np.float32))
        assert_array_equal(sn['dist_limit'], np.array([0.007], np.float32))
        do = so['dist']
        dn = sn['dist']

        # clean out distances > 0.007 in C code
        do.data[do.data > 0.007] = 0
        do.eliminate_zeros()

        # make sure we have some comparable distances
        assert_true(np.sum(do.data < 0.007) > 400)

        # do comparison over the region computed
        d = (do - dn)[:sn['vertno'][n_do - 1]][:, :sn['vertno'][n_do - 1]]
        assert_allclose(np.zeros_like(d.data), d.data, rtol=0, atol=1e-6)
dataset/ETHPy150Open mne-tools/mne-python/mne/tests/test_source_space.py/test_add_source_space_distances_limited