def test_simulate_round_trip():
    """Test simulate_raw round trip calculations."""
    # Check a diagonal round-trip
    raw, src, stc, trans, sphere = _get_data()
    raw.pick_types(meg=True, stim=True)
    bem = read_bem_solution(bem_1_fname)
    old_bem = bem.copy()
    old_src = src.copy()
    old_trans = trans.copy()
    fwd = make_forward_solution(raw.info, trans, src, bem)
    # no omissions
    assert (sum(len(s['vertno']) for s in src) ==
            sum(len(s['vertno']) for s in fwd['src']) ==
            36)
    # make sure things were not modified
    assert (old_bem['surfs'][0]['coord_frame'] ==
            bem['surfs'][0]['coord_frame'])
    assert trans == old_trans
    _compare_source_spaces(src, old_src)
    data = np.eye(fwd['nsource'])
    raw.crop(0, (len(data) - 1) / raw.info['sfreq'])
    stc = SourceEstimate(data, [s['vertno'] for s in fwd['src']],
                         0, 1. / raw.info['sfreq'])
    for use_cps in (False, True):
        this_raw = simulate_raw(raw, stc, trans, src, bem, cov=None,
                                use_cps=use_cps)
        this_raw.pick_types(meg=True, eeg=True)
        assert (old_bem['surfs'][0]['coord_frame'] ==
                bem['surfs'][0]['coord_frame'])
        assert trans == old_trans
        _compare_source_spaces(src, old_src)
        this_fwd = convert_forward_solution(fwd, force_fixed=True,
                                            use_cps=use_cps)
        assert_allclose(this_raw[:][0], this_fwd['sol']['data'],
                        atol=1e-12, rtol=1e-6)

def _compare_forwards(fwd, fwd_py, n_sensors, n_src,
                      meg_rtol=1e-4, meg_atol=1e-9,
                      eeg_rtol=1e-3, eeg_atol=1e-3):
    """Helper to test forwards"""
    # check source spaces
    assert_equal(len(fwd['src']), len(fwd_py['src']))
    _compare_source_spaces(fwd['src'], fwd_py['src'], mode='approx')
    for surf_ori in [False, True]:
        if surf_ori:
            # use copy here to leave our originals unmodified
            fwd = convert_forward_solution(fwd, surf_ori, copy=True)
            fwd_py = convert_forward_solution(fwd, surf_ori, copy=True)

        for key in ['nchan', 'source_nn', 'source_rr', 'source_ori',
                    'surf_ori', 'coord_frame', 'nsource']:
            print(key)
            assert_allclose(fwd_py[key], fwd[key], rtol=1e-4, atol=1e-7)
        assert_allclose(fwd_py['mri_head_t']['trans'],
                        fwd['mri_head_t']['trans'], rtol=1e-5, atol=1e-8)

        assert_equal(fwd_py['sol']['data'].shape, (n_sensors, n_src))
        assert_equal(len(fwd['sol']['row_names']), n_sensors)
        assert_equal(len(fwd_py['sol']['row_names']), n_sensors)

        # check MEG
        assert_allclose(fwd['sol']['data'][:306],
                        fwd_py['sol']['data'][:306],
                        rtol=meg_rtol, atol=meg_atol,
                        err_msg='MEG mismatch')
        # check EEG
        if fwd['sol']['data'].shape[0] > 306:
            assert_allclose(fwd['sol']['data'][306:],
                            fwd_py['sol']['data'][306:],
                            rtol=eeg_rtol, atol=eeg_atol,
                            err_msg='EEG mismatch')

def test_morph_source_spaces():
    """Test morphing of source spaces."""
    src = read_source_spaces(fname_fs)
    src_morph = read_source_spaces(fname_morph)
    src_morph_py = morph_source_spaces(src, 'sample',
                                       subjects_dir=subjects_dir)
    _compare_source_spaces(src_morph, src_morph_py, mode='approx')

def _compare_forwards(fwd, fwd_py, n_sensors, n_src, meg_rtol=1e-4, meg_atol=1e-9, eeg_rtol=1e-3, eeg_atol=1e-3):
    """Helper to test forwards"""
    # check source spaces
    assert_equal(len(fwd["src"]), len(fwd_py["src"]))
    _compare_source_spaces(fwd["src"], fwd_py["src"], mode="approx")
    for surf_ori in [False, True]:
        if surf_ori:
            # use copy here to leave our originals unmodified
            fwd = convert_forward_solution(fwd, surf_ori, copy=True)
            fwd_py = convert_forward_solution(fwd, surf_ori, copy=True)

        for key in ["nchan", "source_nn", "source_rr", "source_ori", "surf_ori", "coord_frame", "nsource"]:
            print(key)
            assert_allclose(fwd_py[key], fwd[key], rtol=1e-4, atol=1e-7)
        assert_allclose(fwd_py["mri_head_t"]["trans"], fwd["mri_head_t"]["trans"], rtol=1e-5, atol=1e-8)

        assert_equal(fwd_py["sol"]["data"].shape, (n_sensors, n_src))
        assert_equal(len(fwd["sol"]["row_names"]), n_sensors)
        assert_equal(len(fwd_py["sol"]["row_names"]), n_sensors)

        # check MEG
        assert_allclose(
            fwd["sol"]["data"][:306], fwd_py["sol"]["data"][:306], rtol=meg_rtol, atol=meg_atol, err_msg="MEG mismatch"
        )
        # check EEG
        if fwd["sol"]["data"].shape[0] > 306:
            assert_allclose(
                fwd["sol"]["data"][306:],
                fwd_py["sol"]["data"][306:],
                rtol=eeg_rtol,
                atol=eeg_atol,
                err_msg="EEG mismatch",
            )

def test_other_volume_source_spaces():
    """Test setting up other volume source spaces"""
    # these are split off because they require the MNE tools, and
    # Travis doesn't seem to like them

    # let's try the spherical one (no bem or surf supplied)
    tempdir = _TempDir()
    temp_name = op.join(tempdir, 'temp-src.fif')
    run_subprocess(['mne_volume_source_space',
                    '--grid', '7.0',
                    '--src', temp_name,
                    '--mri', fname_mri])
    src = read_source_spaces(temp_name)
    src_new = setup_volume_source_space('sample', temp_name, pos=7.0,
                                        mri=fname_mri,
                                        subjects_dir=subjects_dir)
    _compare_source_spaces(src, src_new, mode='approx')
    del src
    del src_new
    assert_raises(ValueError, setup_volume_source_space, 'sample', temp_name,
                  pos=7.0, sphere=[1., 1.], mri=fname_mri,  # bad sphere
                  subjects_dir=subjects_dir)

    # now without MRI argument, it should give an error when we try
    # to read it
    run_subprocess(['mne_volume_source_space',
                    '--grid', '7.0',
                    '--src', temp_name])
    assert_raises(ValueError, read_source_spaces, temp_name)

def test_source_space_from_label():
    """Test generating a source space from volume label."""
    tempdir = _TempDir()
    aseg_fname = op.join(subjects_dir, 'sample', 'mri', 'aseg.mgz')
    label_names = get_volume_labels_from_aseg(aseg_fname)
    volume_label = label_names[int(np.random.rand() * len(label_names))]

    # Test pos as dict
    pos = dict()
    pytest.raises(ValueError, setup_volume_source_space, 'sample', pos=pos,
                  volume_label=volume_label, mri=aseg_fname)

    # Test no mri provided
    pytest.raises(RuntimeError, setup_volume_source_space, 'sample', mri=None,
                  volume_label=volume_label)

    # Test invalid volume label
    pytest.raises(ValueError, setup_volume_source_space, 'sample',
                  volume_label='Hello World!', mri=aseg_fname)

    src = setup_volume_source_space('sample', subjects_dir=subjects_dir,
                                    volume_label=volume_label, mri=aseg_fname,
                                    add_interpolator=False)
    assert_equal(volume_label, src[0]['seg_name'])

    # test reading and writing
    out_name = op.join(tempdir, 'temp-src.fif')
    write_source_spaces(out_name, src)
    src_from_file = read_source_spaces(out_name)
    _compare_source_spaces(src, src_from_file, mode='approx')

def test_simulate_round_trip(raw_data):
    """Test simulate_raw round trip calculations."""
    # Check a diagonal round-trip
    raw, src, stc, trans, sphere = raw_data
    raw.pick_types(meg=True, stim=True)
    bem = read_bem_solution(bem_1_fname)
    old_bem = bem.copy()
    old_src = src.copy()
    old_trans = trans.copy()
    fwd = make_forward_solution(raw.info, trans, src, bem)
    # no omissions
    assert (sum(len(s['vertno']) for s in src) ==
            sum(len(s['vertno']) for s in fwd['src']) ==
            36)
    # make sure things were not modified
    assert (old_bem['surfs'][0]['coord_frame'] ==
            bem['surfs'][0]['coord_frame'])
    assert trans == old_trans
    _compare_source_spaces(src, old_src)
    data = np.eye(fwd['nsource'])
    raw.crop(0, (len(data) - 1) / raw.info['sfreq'])
    stc = SourceEstimate(data, [s['vertno'] for s in fwd['src']],
                         0, 1. / raw.info['sfreq'])
    for use_fwd in (None, fwd):
        if use_fwd is None:
            use_trans, use_src, use_bem = trans, src, bem
        else:
            use_trans = use_src = use_bem = None
        with pytest.deprecated_call():
            this_raw = simulate_raw(raw, stc, use_trans, use_src, use_bem,
                                    cov=None, forward=use_fwd)
        this_raw.pick_types(meg=True, eeg=True)
        assert (old_bem['surfs'][0]['coord_frame'] ==
                bem['surfs'][0]['coord_frame'])
        assert trans == old_trans
        _compare_source_spaces(src, old_src)
        this_fwd = convert_forward_solution(fwd, force_fixed=True)
        assert_allclose(this_raw[:][0], this_fwd['sol']['data'],
                        atol=1e-12, rtol=1e-6)
    with pytest.raises(ValueError, match='If forward is not None then'):
        simulate_raw(raw.info, stc, trans, src, bem, forward=fwd)
    # Not iterable
    with pytest.raises(TypeError, match='SourceEstimate, tuple, or iterable'):
        simulate_raw(raw.info, 0., trans, src, bem, None)
    # STC with a source that `src` does not have
    assert 0 not in src[0]['vertno']
    vertices = [[0, fwd['src'][0]['vertno'][0]], []]
    stc_bad = SourceEstimate(data[:2], vertices, 0, 1. / raw.info['sfreq'])
    with pytest.warns(RuntimeWarning,
                      match='1 of 2 SourceEstimate vertices'):
        simulate_raw(raw.info, stc_bad, trans, src, bem)
    assert 0 not in fwd['src'][0]['vertno']
    with pytest.warns(RuntimeWarning,
                      match='1 of 2 SourceEstimate vertices'):
        simulate_raw(raw.info, stc_bad, None, None, None, forward=fwd)
    # dev_head_t mismatch
    fwd['info']['dev_head_t']['trans'][0, 0] = 1.
    with pytest.raises(ValueError, match='dev_head_t.*does not match'):
        simulate_raw(raw.info, stc, None, None, None, forward=fwd)

def test_volume_source_space():
    """Test setting up volume source spaces
    """
    tempdir = _TempDir()
    src = read_source_spaces(fname_vol)
    temp_name = op.join(tempdir, 'temp-src.fif')
    # The one in the sample dataset (uses bem as bounds)
    src_new = setup_volume_source_space('sample', temp_name, pos=7.0,
                                        bem=fname_bem, mri=fname_mri,
                                        subjects_dir=subjects_dir)
    _compare_source_spaces(src, src_new, mode='approx')
    del src_new
    src_new = read_source_spaces(temp_name)
    _compare_source_spaces(src, src_new, mode='approx')

def test_write_source_space():
    """Test reading and writing of source spaces."""
    tempdir = _TempDir()
    src0 = read_source_spaces(fname, patch_stats=False)
    write_source_spaces(op.join(tempdir, 'tmp-src.fif'), src0)
    src1 = read_source_spaces(op.join(tempdir, 'tmp-src.fif'),
                              patch_stats=False)
    _compare_source_spaces(src0, src1)

    # test warnings on bad filenames
    src_badname = op.join(tempdir, 'test-bad-name.fif.gz')
    with pytest.warns(RuntimeWarning, match='-src.fif'):
        write_source_spaces(src_badname, src0)
    with pytest.warns(RuntimeWarning, match='-src.fif'):
        read_source_spaces(src_badname)

def test_write_source_space():
    """Test reading and writing of source spaces
    """
    tempdir = _TempDir()
    src0 = read_source_spaces(fname, add_geom=False)
    write_source_spaces(op.join(tempdir, 'tmp-src.fif'), src0)
    src1 = read_source_spaces(op.join(tempdir, 'tmp-src.fif'), add_geom=False)
    _compare_source_spaces(src0, src1)

    # test warnings on bad filenames
    with warnings.catch_warnings(record=True) as w:
        warnings.simplefilter('always')
        src_badname = op.join(tempdir, 'test-bad-name.fif.gz')
        write_source_spaces(src_badname, src0)
        read_source_spaces(src_badname)
    assert_equal(len(w), 2)

def test_setup_source_space_spacing(tmpdir, spacing):
    """Test setting up surface source spaces using a given spacing."""
    tempdir = str(tmpdir)
    copytree(op.join(subjects_dir, 'sample'), op.join(tempdir, 'sample'))
    args = [] if spacing == 7 else ['--spacing', str(spacing)]
    with modified_env(SUBJECTS_DIR=tempdir, SUBJECT='sample'):
        run_subprocess(['mne_setup_source_space'] + args)
    src = read_source_spaces(op.join(tempdir, 'sample', 'bem',
                                     'sample-%d-src.fif' % spacing))
    src_new = setup_source_space('sample', spacing=spacing, add_dist=False,
                                 subjects_dir=subjects_dir)
    _compare_source_spaces(src, src_new, mode='approx', nearest=True)
    # Degenerate conditions
    with pytest.raises(TypeError, match='spacing must be.*got.*float.*'):
        setup_source_space('sample', 7., subjects_dir=subjects_dir)
    with pytest.raises(ValueError, match='spacing must be >= 2, got 1'):
        setup_source_space('sample', 1, subjects_dir=subjects_dir)

def _compare_forwards(fwd, fwd_py, n_sensors, n_src,
                      meg_rtol=1e-4, meg_atol=1e-9,
                      eeg_rtol=1e-3, eeg_atol=1e-3):
    """Test forwards."""
    # check source spaces
    assert_equal(len(fwd['src']), len(fwd_py['src']))
    _compare_source_spaces(fwd['src'], fwd_py['src'], mode='approx')
    for surf_ori, force_fixed in product([False, True], [False, True]):
        # use copy here to leave our originals unmodified
        fwd = convert_forward_solution(fwd, surf_ori, force_fixed, copy=True,
                                       use_cps=True)
        fwd_py = convert_forward_solution(fwd_py, surf_ori, force_fixed,
                                          copy=True, use_cps=True)
        check_src = n_src // 3 if force_fixed else n_src

        for key in ('nchan', 'source_rr', 'source_ori',
                    'surf_ori', 'coord_frame', 'nsource'):
            assert_allclose(fwd_py[key], fwd[key], rtol=1e-4, atol=1e-7,
                            err_msg=key)
        # In surf_ori=True only Z matters for source_nn
        if surf_ori and not force_fixed:
            ori_sl = slice(2, None, 3)
        else:
            ori_sl = slice(None)
        assert_allclose(fwd_py['source_nn'][ori_sl], fwd['source_nn'][ori_sl],
                        rtol=1e-4, atol=1e-6)
        assert_allclose(fwd_py['mri_head_t']['trans'],
                        fwd['mri_head_t']['trans'], rtol=1e-5, atol=1e-8)

        assert_equal(fwd_py['sol']['data'].shape, (n_sensors, check_src))
        assert_equal(len(fwd['sol']['row_names']), n_sensors)
        assert_equal(len(fwd_py['sol']['row_names']), n_sensors)

        # check MEG
        assert_allclose(fwd['sol']['data'][:306, ori_sl],
                        fwd_py['sol']['data'][:306, ori_sl],
                        rtol=meg_rtol, atol=meg_atol,
                        err_msg='MEG mismatch')
        # check EEG
        if fwd['sol']['data'].shape[0] > 306:
            assert_allclose(fwd['sol']['data'][306:, ori_sl],
                            fwd_py['sol']['data'][306:, ori_sl],
                            rtol=eeg_rtol, atol=eeg_atol,
                            err_msg='EEG mismatch')

def _compare_forwards(fwd, fwd_py, n_sensors, n_src, meg_rtol=1e-4, meg_atol=1e-9, eeg_rtol=1e-3, eeg_atol=1e-3):
    """Helper to test forwards"""
    # check source spaces
    assert_equal(len(fwd["src"]), len(fwd_py["src"]))
    _compare_source_spaces(fwd["src"], fwd_py["src"], mode="approx")
    for surf_ori, force_fixed in product([False, True], [False, True]):
        # use copy here to leave our originals unmodified
        fwd = convert_forward_solution(fwd, surf_ori, force_fixed, copy=True)
        fwd_py = convert_forward_solution(fwd_py, surf_ori, force_fixed, copy=True)
        check_src = n_src // 3 if force_fixed else n_src

        for key in ("nchan", "source_rr", "source_ori", "surf_ori", "coord_frame", "nsource"):
            assert_allclose(fwd_py[key], fwd[key], rtol=1e-4, atol=1e-7, err_msg=key)
        # In surf_ori=True only Z matters for source_nn
        if surf_ori and not force_fixed:
            ori_sl = slice(2, None, 3)
        else:
            ori_sl = slice(None)
        assert_allclose(fwd_py["source_nn"][ori_sl], fwd["source_nn"][ori_sl], rtol=1e-4, atol=1e-6)
        assert_allclose(fwd_py["mri_head_t"]["trans"], fwd["mri_head_t"]["trans"], rtol=1e-5, atol=1e-8)

        assert_equal(fwd_py["sol"]["data"].shape, (n_sensors, check_src))
        assert_equal(len(fwd["sol"]["row_names"]), n_sensors)
        assert_equal(len(fwd_py["sol"]["row_names"]), n_sensors)

        # check MEG
        assert_allclose(
            fwd["sol"]["data"][:306, ori_sl],
            fwd_py["sol"]["data"][:306, ori_sl],
            rtol=meg_rtol,
            atol=meg_atol,
            err_msg="MEG mismatch",
        )
        # check EEG
        if fwd["sol"]["data"].shape[0] > 306:
            assert_allclose(
                fwd["sol"]["data"][306:, ori_sl],
                fwd_py["sol"]["data"][306:, ori_sl],
                rtol=eeg_rtol,
                atol=eeg_atol,
                err_msg="EEG mismatch",
            )

def test_other_volume_source_spaces():
    """Test setting up other volume source spaces."""
    # these are split off because they require the MNE tools, and
    # Travis doesn't seem to like them

    # let's try the spherical one (no bem or surf supplied)
    tempdir = _TempDir()
    temp_name = op.join(tempdir, 'temp-src.fif')
    run_subprocess(['mne_volume_source_space',
                    '--grid', '7.0',
                    '--src', temp_name,
                    '--mri', fname_mri])
    src = read_source_spaces(temp_name)
    src_new = setup_volume_source_space(None, pos=7.0, mri=fname_mri,
                                        subjects_dir=subjects_dir)
    # we use a more accurate elimination criteria, so let's fix the MNE-C
    # source space
    assert len(src_new[0]['vertno']) == 7497
    assert len(src) == 1
    assert len(src_new) == 1
    good_mask = np.in1d(src[0]['vertno'], src_new[0]['vertno'])
    src[0]['inuse'][src[0]['vertno'][~good_mask]] = 0
    assert src[0]['inuse'].sum() == 7497
    src[0]['vertno'] = src[0]['vertno'][good_mask]
    assert len(src[0]['vertno']) == 7497
    src[0]['nuse'] = len(src[0]['vertno'])
    assert src[0]['nuse'] == 7497
    _compare_source_spaces(src_new, src, mode='approx')
    assert 'volume, shape' in repr(src)
    del src
    del src_new
    pytest.raises(ValueError, setup_volume_source_space, 'sample', pos=7.0,
                  sphere=[1., 1.], mri=fname_mri,  # bad sphere
                  subjects_dir=subjects_dir)

    # now without MRI argument, it should give an error when we try
    # to read it
    run_subprocess(['mne_volume_source_space',
                    '--grid', '7.0',
                    '--src', temp_name])
    pytest.raises(ValueError, read_source_spaces, temp_name)

def test_volume_source_space():
    """Test setting up volume source spaces
    """
    tempdir = _TempDir()
    src = read_source_spaces(fname_vol)
    temp_name = op.join(tempdir, 'temp-src.fif')
    surf = read_bem_surfaces(fname_bem, s_id=FIFF.FIFFV_BEM_SURF_ID_BRAIN)
    surf['rr'] *= 1e3  # convert to mm
    # The one in the testing dataset (uses bem as bounds)
    for bem, surf in zip((fname_bem, None), (None, surf)):
        src_new = setup_volume_source_space('sample', temp_name, pos=7.0,
                                            bem=bem, surface=surf,
                                            mri=fname_mri,
                                            subjects_dir=subjects_dir)
        _compare_source_spaces(src, src_new, mode='approx')
        del src_new
        src_new = read_source_spaces(temp_name)
        _compare_source_spaces(src, src_new, mode='approx')
    assert_raises(IOError, setup_volume_source_space, 'sample', temp_name,
                  pos=7.0, bem=None, surface='foo',  # bad surf
                  mri=fname_mri, subjects_dir=subjects_dir)

def test_discrete_source_space():
    """Test setting up (and reading/writing) discrete source spaces
    """
    tempdir = _TempDir()
    src = read_source_spaces(fname)
    v = src[0]['vertno']

    # let's make a discrete version with the C code, and with ours
    temp_name = op.join(tempdir, 'temp-src.fif')
    try:
        # save
        temp_pos = op.join(tempdir, 'temp-pos.txt')
        np.savetxt(temp_pos, np.c_[src[0]['rr'][v], src[0]['nn'][v]])
        # let's try the spherical one (no bem or surf supplied)
        run_subprocess(['mne_volume_source_space', '--meters',
                        '--pos', temp_pos, '--src', temp_name])
        src_c = read_source_spaces(temp_name)
        pos_dict = dict(rr=src[0]['rr'][v], nn=src[0]['nn'][v])
        src_new = setup_volume_source_space('sample', None,
                                            pos=pos_dict,
                                            subjects_dir=subjects_dir)
        _compare_source_spaces(src_c, src_new, mode='approx')
        assert_allclose(src[0]['rr'][v], src_new[0]['rr'],
                        rtol=1e-3, atol=1e-6)
        assert_allclose(src[0]['nn'][v], src_new[0]['nn'],
                        rtol=1e-3, atol=1e-6)

        # now do writing
        write_source_spaces(temp_name, src_c)
        src_c2 = read_source_spaces(temp_name)
        _compare_source_spaces(src_c, src_c2)

        # now do MRI
        assert_raises(ValueError, setup_volume_source_space, 'sample',
                      pos=pos_dict, mri=fname_mri)
        assert_equal(repr(src_new), repr(src_c))
        assert_equal(src_new.kind, 'discrete')
    finally:
        if op.isfile(temp_name):
            os.remove(temp_name)

def test_volume_source_space():
    """Test setting up volume source spaces."""
    tempdir = _TempDir()
    src = read_source_spaces(fname_vol)
    temp_name = op.join(tempdir, 'temp-src.fif')
    surf = read_bem_surfaces(fname_bem, s_id=FIFF.FIFFV_BEM_SURF_ID_BRAIN)
    surf['rr'] *= 1e3  # convert to mm
    # The one in the testing dataset (uses bem as bounds)
    for bem, surf in zip((fname_bem, None), (None, surf)):
        src_new = setup_volume_source_space(
            'sample', pos=7.0, bem=bem, surface=surf, mri='T1.mgz',
            subjects_dir=subjects_dir)
        write_source_spaces(temp_name, src_new, overwrite=True)
        src[0]['subject_his_id'] = 'sample'  # XXX: to make comparison pass
        _compare_source_spaces(src, src_new, mode='approx')
        del src_new
        src_new = read_source_spaces(temp_name)
        _compare_source_spaces(src, src_new, mode='approx')
    pytest.raises(IOError, setup_volume_source_space, 'sample',
                  pos=7.0, bem=None, surface='foo',  # bad surf
                  mri=fname_mri, subjects_dir=subjects_dir)
    assert repr(src) == repr(src_new)
    assert src.kind == 'volume'
    # Spheres
    sphere = make_sphere_model(r0=(0., 0., 0.), head_radius=0.1,
                               relative_radii=(0.9, 1.0), sigmas=(0.33, 1.0))
    src = setup_volume_source_space(pos=10)
    src_new = setup_volume_source_space(pos=10, sphere=sphere)
    _compare_source_spaces(src, src_new, mode='exact')
    pytest.raises(ValueError, setup_volume_source_space, sphere='foo')
    # Need a radius
    sphere = make_sphere_model(head_radius=None)
    pytest.raises(ValueError, setup_volume_source_space, sphere=sphere)

def test_volume_source_space():
    """Test setting up volume source spaces."""
    tempdir = _TempDir()
    src = read_source_spaces(fname_vol)
    temp_name = op.join(tempdir, 'temp-src.fif')
    surf = read_bem_surfaces(fname_bem, s_id=FIFF.FIFFV_BEM_SURF_ID_BRAIN)
    surf['rr'] *= 1e3  # convert to mm
    # The one in the testing dataset (uses bem as bounds)
    for bem, surf in zip((fname_bem, None), (None, surf)):
        src_new = setup_volume_source_space(
            'sample', pos=7.0, bem=bem, surface=surf, mri='T1.mgz',
            subjects_dir=subjects_dir)
        write_source_spaces(temp_name, src_new, overwrite=True)
        src[0]['subject_his_id'] = 'sample'  # XXX: to make comparison pass
        _compare_source_spaces(src, src_new, mode='approx')
        del src_new
        src_new = read_source_spaces(temp_name)
        _compare_source_spaces(src, src_new, mode='approx')
    assert_raises(IOError, setup_volume_source_space, 'sample',
                  pos=7.0, bem=None, surface='foo',  # bad surf
                  mri=fname_mri, subjects_dir=subjects_dir)
    assert_equal(repr(src), repr(src_new))
    assert_equal(src.kind, 'volume')

def test_setup_source_space():
    """Test setting up ico, oct, and all source spaces
    """
    tempdir = _TempDir()
    fname_ico = op.join(data_path, 'subjects', 'fsaverage', 'bem',
                        'fsaverage-ico-5-src.fif')
    # first lets test some input params
    assert_raises(ValueError, setup_source_space, 'sample', spacing='oct',
                  add_dist=False)
    assert_raises(ValueError, setup_source_space, 'sample', spacing='octo',
                  add_dist=False)
    assert_raises(ValueError, setup_source_space, 'sample', spacing='oct6e',
                  add_dist=False)
    assert_raises(ValueError, setup_source_space, 'sample', spacing='7emm',
                  add_dist=False)
    assert_raises(ValueError, setup_source_space, 'sample', spacing='alls',
                  add_dist=False)
    assert_raises(IOError, setup_source_space, 'sample', spacing='oct6',
                  subjects_dir=subjects_dir, add_dist=False)

    # ico 5 (fsaverage) - write to temp file
    src = read_source_spaces(fname_ico)
    temp_name = op.join(tempdir, 'temp-src.fif')
    with warnings.catch_warnings(record=True):  # sklearn equiv neighbors
        warnings.simplefilter('always')
        src_new = setup_source_space('fsaverage', temp_name, spacing='ico5',
                                     subjects_dir=subjects_dir, add_dist=False,
                                     overwrite=True)
    _compare_source_spaces(src, src_new, mode='approx')
    assert_equal(repr(src), repr(src_new))
    assert_equal(repr(src).count('surface ('), 2)
    assert_array_equal(src[0]['vertno'], np.arange(10242))
    assert_array_equal(src[1]['vertno'], np.arange(10242))

    # oct-6 (sample) - auto filename + IO
    src = read_source_spaces(fname)
    temp_name = op.join(tempdir, 'temp-src.fif')
    with warnings.catch_warnings(record=True):  # sklearn equiv neighbors
        warnings.simplefilter('always')
        src_new = setup_source_space('sample', temp_name, spacing='oct6',
                                     subjects_dir=subjects_dir,
                                     overwrite=True, add_dist=False)
    _compare_source_spaces(src, src_new, mode='approx', nearest=False)
    src_new = read_source_spaces(temp_name)
    _compare_source_spaces(src, src_new, mode='approx', nearest=False)

    # all source points - no file writing
    src_new = setup_source_space('sample', None, spacing='all',
                                 subjects_dir=subjects_dir, add_dist=False)
    assert_true(src_new[0]['nuse'] == len(src_new[0]['rr']))
    assert_true(src_new[1]['nuse'] == len(src_new[1]['rr']))

    # dense source space to hit surf['inuse'] lines of _create_surf_spacing
    assert_raises(RuntimeError, setup_source_space, 'sample', None,
                  spacing='ico6', subjects_dir=subjects_dir, add_dist=False)

def test_combine_source_spaces():
    """Test combining source spaces."""
    tempdir = _TempDir()
    aseg_fname = op.join(subjects_dir, 'sample', 'mri', 'aseg.mgz')
    label_names = get_volume_labels_from_aseg(aseg_fname)
    volume_labels = [label_names[int(np.random.rand() * len(label_names))]
                     for ii in range(2)]

    # get a surface source space (no need to test creation here)
    srf = read_source_spaces(fname, patch_stats=False)

    # setup 2 volume source spaces
    vol = setup_volume_source_space('sample', subjects_dir=subjects_dir,
                                    volume_label=volume_labels[0],
                                    mri=aseg_fname, add_interpolator=False)

    # setup a discrete source space
    rr = rng.randint(0, 20, (100, 3)) * 1e-3
    nn = np.zeros(rr.shape)
    nn[:, -1] = 1
    pos = {'rr': rr, 'nn': nn}
    disc = setup_volume_source_space('sample', subjects_dir=subjects_dir,
                                     pos=pos, verbose='error')

    # combine source spaces
    src = srf + vol + disc

    # test addition of source spaces
    assert_equal(type(src), SourceSpaces)
    assert_equal(len(src), 4)

    # test reading and writing
    src_out_name = op.join(tempdir, 'temp-src.fif')
    src.save(src_out_name)
    src_from_file = read_source_spaces(src_out_name)
    _compare_source_spaces(src, src_from_file, mode='approx')
    assert_equal(repr(src), repr(src_from_file))
    assert_equal(src.kind, 'mixed')

    # test that all source spaces are in MRI coordinates
    coord_frames = np.array([s['coord_frame'] for s in src])
    assert (coord_frames == FIFF.FIFFV_COORD_MRI).all()

    # test errors for export_volume
    image_fname = op.join(tempdir, 'temp-image.mgz')

    # source spaces with no volume
    pytest.raises(ValueError, srf.export_volume, image_fname, verbose='error')

    # unrecognized source type
    disc2 = disc.copy()
    disc2[0]['type'] = 'kitty'
    src_unrecognized = src + disc2
    pytest.raises(ValueError, src_unrecognized.export_volume, image_fname,
                  verbose='error')

    # unrecognized file type
    bad_image_fname = op.join(tempdir, 'temp-image.png')
    # vertices outside vol space warning
    pytest.raises(ValueError, src.export_volume, bad_image_fname,
                  verbose='error')

    # mixed coordinate frames
    disc3 = disc.copy()
    disc3[0]['coord_frame'] = 10
    src_mixed_coord = src + disc3
    pytest.raises(ValueError, src_mixed_coord.export_volume, image_fname,
                  verbose='error')