Example #1
0
def test_gamma_map():
    """Test Gamma MAP inverse"""
    forward = read_forward_solution(fname_fwd, force_fixed=False,
                                    surf_ori=True)
    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0))
    evoked.resample(50)
    evoked.crop(tmin=0, tmax=0.3)

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    alpha = 0.2
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                    xyz_same_gamma=True, update_mode=1, verbose=False)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertices)[idx] == 96397)

    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                    xyz_same_gamma=False, update_mode=1, verbose=False)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertices)[idx] == 82010)

    # force fixed orientation
    stc, res = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                         xyz_same_gamma=False, update_mode=2,
                         loose=None, return_residual=True, verbose=False)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    # assert_true(np.concatenate(stc.vertices)[idx] == 83398)  # XXX FIX
    assert_array_almost_equal(evoked.times, res.times)
def test_gamma_map():
    """Test Gamma MAP inverse"""
    forward = read_forward_solution(fname_fwd, force_fixed=False,
                                    surf_ori=True)
    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to nice window near samp border

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    alpha = 0.5
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=True, update_mode=1)
    _check_stc(stc, evoked, 68477)

    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=1)
    _check_stc(stc, evoked, 82010)

    # force fixed orientation
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=2,
                    loose=None, return_residual=False)
    _check_stc(stc, evoked, 85739, 20)
Example #3
0
def test_gamma_map():
    """Test Gamma MAP inverse"""
    forward = read_forward_solution(fname_fwd)
    forward = convert_forward_solution(forward, surf_ori=True)

    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    alpha = 0.5
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=True, update_mode=1)
    _check_stc(stc, evoked, 68477)

    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=1)
    _check_stc(stc, evoked, 82010)

    dips = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                     xyz_same_gamma=False, update_mode=1,
                     return_as_dipoles=True)
    assert_true(isinstance(dips[0], Dipole))
    stc_dip = make_stc_from_dipoles(dips, forward['src'])
    _check_stcs(stc, stc_dip)

    # force fixed orientation
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=2,
                    loose=0, return_residual=False)
    _check_stc(stc, evoked, 85739, 20)
def test_gamma_map():
    """Test Gamma MAP inverse."""
    forward = read_forward_solution(fname_fwd)
    forward = convert_forward_solution(forward, surf_ori=True)

    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.14)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info, rank=None)

    alpha = 0.5
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=True, update_mode=1)
    _check_stc(stc, evoked, 68477, 'lh', fwd=forward)

    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=1)
    _check_stc(stc, evoked, 82010, 'lh', fwd=forward)

    dips = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                     xyz_same_gamma=False, update_mode=1,
                     return_as_dipoles=True)
    assert (isinstance(dips[0], Dipole))
    stc_dip = make_stc_from_dipoles(dips, forward['src'])
    _check_stcs(stc, stc_dip)

    # force fixed orientation
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=2,
                    loose=0, return_residual=False)
    _check_stc(stc, evoked, 85739, 'lh', fwd=forward, ratio=20.)
Example #5
0
def test_gamma_map():
    """Test Gamma MAP inverse"""
    forward = read_forward_solution(fname_fwd, force_fixed=False,
                                    surf_ori=True)
    evoked = fiff.Evoked(fname_evoked, setno=0, baseline=(None, 0))
    evoked.crop(tmin=0, tmax=0.3)

    cov = read_cov(fname_cov)
    cov = mne.cov.regularize(cov, evoked.info)

    alpha = 0.2
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                    xyz_same_gamma=True, update_mode=1)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertno)[idx] == 96397)

    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                    xyz_same_gamma=False, update_mode=1)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertno)[idx] == 82010)

    # force fixed orientation
    stc, res = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                         xyz_same_gamma=False, update_mode=2,
                         loose=None, return_residual=True)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertno)[idx] == 83398)

    assert_array_almost_equal(evoked.times, res.times)
def test_gamma_map():
    """Test Gamma MAP inverse"""

    forward = read_forward_solution(fname_fwd,
                                    force_fixed=False,
                                    surf_ori=True)
    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0))
    evoked.resample(50)
    evoked.crop(tmin=0, tmax=0.3)

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    alpha = 0.2
    stc = gamma_map(evoked,
                    forward,
                    cov,
                    alpha,
                    tol=1e-5,
                    xyz_same_gamma=True,
                    update_mode=1,
                    verbose=False)
    assert_array_almost_equal(stc.times, evoked.times, 5)
    idx = np.argmax(np.sum(stc.data**2, axis=1))
    assert_true(np.concatenate(stc.vertices)[idx] == 96397)

    stc = gamma_map(evoked,
                    forward,
                    cov,
                    alpha,
                    tol=1e-5,
                    xyz_same_gamma=False,
                    update_mode=1,
                    verbose=False)
    assert_array_almost_equal(stc.times, evoked.times, 5)
    idx = np.argmax(np.sum(stc.data**2, axis=1))
    assert_true(np.concatenate(stc.vertices)[idx] == 82010)

    # force fixed orientation
    stc, res = gamma_map(evoked,
                         forward,
                         cov,
                         alpha,
                         tol=1e-5,
                         xyz_same_gamma=False,
                         update_mode=2,
                         loose=None,
                         return_residual=True,
                         verbose=False)
    assert_array_almost_equal(stc.times, evoked.times, 5)
    idx = np.argmax(np.sum(stc.data**2, axis=1))
    # assert_true(np.concatenate(stc.vertices)[idx] == 83398)  # XXX FIX
    assert_array_almost_equal(evoked.times, res.times)
Example #7
0
def test_gamma_map_vol_sphere():
    """Gamma MAP with a sphere forward and volumic source space."""
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info, rank=None)

    info = evoked.info
    sphere = mne.make_sphere_model(r0=(0., 0., 0.), head_radius=0.080)
    src = mne.setup_volume_source_space(subject=None, pos=30., mri=None,
                                        sphere=(0.0, 0.0, 0.0, 80.0),
                                        bem=None, mindist=5.0,
                                        exclude=2.0)
    fwd = mne.make_forward_solution(info, trans=None, src=src, bem=sphere,
                                    eeg=False, meg=True)

    alpha = 0.5
    pytest.raises(ValueError, gamma_map, evoked, fwd, cov, alpha,
                  loose=0, return_residual=False)

    pytest.raises(ValueError, gamma_map, evoked, fwd, cov, alpha,
                  loose=0.2, return_residual=False)

    stc = gamma_map(evoked, fwd, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=2,
                    return_residual=False)

    assert_array_almost_equal(stc.times, evoked.times, 5)

    # Compare orientation obtained using fit_dipole and gamma_map
    # for a simulated evoked containing a single dipole
    stc = mne.VolSourceEstimate(50e-9 * np.random.RandomState(42).randn(1, 4),
                                vertices=stc.vertices[:1],
                                tmin=stc.tmin,
                                tstep=stc.tstep)
    evoked_dip = mne.simulation.simulate_evoked(fwd, stc, info, cov, nave=1e9,
                                                use_cps=True)

    dip_gmap = gamma_map(evoked_dip, fwd, cov, 0.1, return_as_dipoles=True)

    amp_max = [np.max(d.amplitude) for d in dip_gmap]
    dip_gmap = dip_gmap[np.argmax(amp_max)]
    assert (dip_gmap[0].pos[0] in src[0]['rr'][stc.vertices])

    dip_fit = mne.fit_dipole(evoked_dip, cov, sphere)[0]
    assert (np.abs(np.dot(dip_fit.ori[0], dip_gmap.ori[0])) > 0.99)
def test_gamma_map_vol_sphere():
    """Gamma MAP with a sphere forward and volumic source space."""
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info, rank=None)

    info = evoked.info
    sphere = mne.make_sphere_model(r0=(0., 0., 0.), head_radius=0.080)
    src = mne.setup_volume_source_space(subject=None, pos=30., mri=None,
                                        sphere=(0.0, 0.0, 0.0, 80.0),
                                        bem=None, mindist=5.0,
                                        exclude=2.0)
    fwd = mne.make_forward_solution(info, trans=None, src=src, bem=sphere,
                                    eeg=False, meg=True)

    alpha = 0.5
    pytest.raises(ValueError, gamma_map, evoked, fwd, cov, alpha,
                  loose=0, return_residual=False)

    pytest.raises(ValueError, gamma_map, evoked, fwd, cov, alpha,
                  loose=0.2, return_residual=False)

    stc = gamma_map(evoked, fwd, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=2,
                    return_residual=False)

    assert_array_almost_equal(stc.times, evoked.times, 5)

    # Compare orientation obtained using fit_dipole and gamma_map
    # for a simulated evoked containing a single dipole
    stc = mne.VolSourceEstimate(50e-9 * np.random.RandomState(42).randn(1, 4),
                                vertices=stc.vertices[:1],
                                tmin=stc.tmin,
                                tstep=stc.tstep)
    evoked_dip = mne.simulation.simulate_evoked(fwd, stc, info, cov, nave=1e9,
                                                use_cps=True)

    dip_gmap = gamma_map(evoked_dip, fwd, cov, 0.1, return_as_dipoles=True)

    amp_max = [np.max(d.amplitude) for d in dip_gmap]
    dip_gmap = dip_gmap[np.argmax(amp_max)]
    assert (dip_gmap[0].pos[0] in src[0]['rr'][stc.vertices])

    dip_fit = mne.fit_dipole(evoked_dip, cov, sphere)[0]
    assert (np.abs(np.dot(dip_fit.ori[0], dip_gmap.ori[0])) > 0.99)
Example #9
0
def test_gamma_map_vol_sphere():
    """Gamma MAP with a sphere forward and volumic source space"""
    evoked = read_evokeds(fname_evoked, condition=0, baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    info = evoked.info
    sphere = mne.make_sphere_model(r0=(0., 0., 0.), head_radius=0.080)
    src = mne.setup_volume_source_space(subject=None, pos=15., mri=None,
                                        sphere=(0.0, 0.0, 0.0, 80.0),
                                        bem=None, mindist=5.0,
                                        exclude=2.0)
    fwd = mne.make_forward_solution(info, trans=None, src=src, bem=sphere,
                                    eeg=False, meg=True)

    alpha = 0.5
    assert_raises(ValueError, gamma_map, evoked, fwd, cov, alpha,
                  loose=0, return_residual=False)

    assert_raises(ValueError, gamma_map, evoked, fwd, cov, alpha,
                  loose=0.2, return_residual=False)

    stc = gamma_map(evoked, fwd, cov, alpha, tol=1e-4,
                    xyz_same_gamma=False, update_mode=2,
                    return_residual=False)

    assert_array_almost_equal(stc.times, evoked.times, 5)
def test_gamma_map():
    """Test Gamma MAP inverse"""
    forward = read_forward_solution(fname_fwd,
                                    force_fixed=False,
                                    surf_ori=True)
    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked,
                          condition=0,
                          baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to nice window near samp border

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    alpha = 0.5
    stc = gamma_map(evoked,
                    forward,
                    cov,
                    alpha,
                    tol=1e-4,
                    xyz_same_gamma=True,
                    update_mode=1)
    _check_stc(stc, evoked, 68477)

    stc = gamma_map(evoked,
                    forward,
                    cov,
                    alpha,
                    tol=1e-4,
                    xyz_same_gamma=False,
                    update_mode=1)
    _check_stc(stc, evoked, 82010)

    # force fixed orientation
    stc = gamma_map(evoked,
                    forward,
                    cov,
                    alpha,
                    tol=1e-4,
                    xyz_same_gamma=False,
                    update_mode=2,
                    loose=None,
                    return_residual=False)
    _check_stc(stc, evoked, 85739, 20)
Example #11
0
def test_gamma_map_vol_sphere():
    """Gamma MAP with a sphere forward and volumic source space"""
    evoked = read_evokeds(fname_evoked,
                          condition=0,
                          baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.16)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info)

    info = evoked.info
    sphere = mne.make_sphere_model(r0=(0., 0., 0.), head_radius=0.080)
    src = mne.setup_volume_source_space(subject=None,
                                        pos=15.,
                                        mri=None,
                                        sphere=(0.0, 0.0, 0.0, 80.0),
                                        bem=None,
                                        mindist=5.0,
                                        exclude=2.0)
    fwd = mne.make_forward_solution(info,
                                    trans=None,
                                    src=src,
                                    bem=sphere,
                                    eeg=False,
                                    meg=True)

    alpha = 0.5
    assert_raises(ValueError,
                  gamma_map,
                  evoked,
                  fwd,
                  cov,
                  alpha,
                  loose=None,
                  return_residual=False)

    assert_raises(ValueError,
                  gamma_map,
                  evoked,
                  fwd,
                  cov,
                  alpha,
                  loose=0.2,
                  return_residual=False)

    stc = gamma_map(evoked,
                    fwd,
                    cov,
                    alpha,
                    tol=1e-4,
                    xyz_same_gamma=False,
                    update_mode=2,
                    return_residual=False)

    assert_array_almost_equal(stc.times, evoked.times, 5)
Example #12
0
def test_gamma_map():
    """Test Gamma MAP inverse"""

    alpha = 0.2
    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                    xyz_same_gamma=True, update_mode=1)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertno)[idx] == 96397)

    stc = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                    xyz_same_gamma=False, update_mode=1)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertno)[idx] == 82010)

    # force fixed orientation
    stc, res = gamma_map(evoked, forward, cov, alpha, tol=1e-5,
                         xyz_same_gamma=False, update_mode=2,
                         loose=None, return_residual=True)
    idx = np.argmax(np.sum(stc.data ** 2, axis=1))
    assert_true(np.concatenate(stc.vertno)[idx] == 83398)

    assert_array_almost_equal(evoked.times, res.times)
Example #13
0
def mne_gamma_map(evoked, fwd, noiseCovariance, return_idx=50, alpha=1e-3):

    numberOfDipoles = int(fwd['sol']['data'].shape[1] / 3)
    numberOfTimepoints = evoked._data.shape[1]

    evoked.set_eeg_reference('average', projection=True)

    stc = gamma_map(evoked,
                    fwd,
                    noiseCovariance,
                    alpha,
                    xyz_same_gamma=False,
                    loose=0,
                    return_residual=False,
                    return_as_dipoles=False,
                    verbose=0)

    y_est = dipoles_to_stc(stc, numberOfDipoles, numberOfTimepoints)

    return y_est[:, return_idx]
condition = 'Left visual'
evoked = mne.read_evokeds(evoked_fname, condition=condition,
                          baseline=(None, 0))
evoked.crop(tmin=-50e-3, tmax=300e-3)

# Read the forward solution
forward = mne.read_forward_solution(fwd_fname)

# Read noise noise covariance matrix and regularize it
cov = mne.read_cov(cov_fname)
cov = mne.cov.regularize(cov, evoked.info, rank=None)

# Run the Gamma-MAP method with dipole output
alpha = 0.5
dipoles, residual = gamma_map(
    evoked, forward, cov, alpha, xyz_same_gamma=True, return_residual=True,
    return_as_dipoles=True)

###############################################################################
# Plot dipole activations
plot_dipole_amplitudes(dipoles)

# Plot dipole location of the strongest dipole with MRI slices
idx = np.argmax([np.max(np.abs(dip.amplitude)) for dip in dipoles])
plot_dipole_locations(dipoles[idx], forward['mri_head_t'], 'sample',
                      subjects_dir=subjects_dir, mode='orthoview',
                      idx='amplitude')

# # Plot dipole locations of all dipoles with MRI slices
# for dip in dipoles:
#     plot_dipole_locations(dip, forward['mri_head_t'], 'sample',
condition = 'Left visual'
evoked = mne.read_evokeds(evoked_fname, condition=condition,
                          baseline=(None, 0))
evoked.crop(tmin=-50e-3, tmax=300e-3)

# Read the forward solution
forward = mne.read_forward_solution(fwd_fname, surf_ori=True,
                                    force_fixed=False)

# Read noise covariance matrix and regularize it
cov = mne.read_cov(cov_fname)
cov = mne.cov.regularize(cov, evoked.info)

# Run the Gamma-MAP method
alpha = 0.5
stc, residual = gamma_map(evoked, forward, cov, alpha, xyz_same_gamma=True,
                          return_residual=True)

# View in 2D and 3D ("glass" brain like 3D plot)

# Show the sources as spheres scaled by their strength
scale_factors = np.max(np.abs(stc.data), axis=1)
scale_factors = 0.5 * (1 + scale_factors / np.max(scale_factors))

plot_sparse_source_estimates(
    forward['src'], stc, bgcolor=(1, 1, 1),
    modes=['sphere'], opacity=0.1, scale_factors=(scale_factors, None),
    fig_name="Gamma-MAP")

# Show the evoked response and the residual for gradiometers
ylim = dict(grad=[-120, 120])
evoked.pick_types(meg='grad', exclude='bads')
def test_gamma_map_standard():
    """Test Gamma MAP inverse."""
    forward = read_forward_solution(fname_fwd)
    forward = convert_forward_solution(forward, surf_ori=True)

    forward = pick_types_forward(forward, meg=False, eeg=True)
    evoked = read_evokeds(fname_evoked,
                          condition=0,
                          baseline=(None, 0),
                          proj=False)
    evoked.resample(50, npad=100)
    evoked.crop(tmin=0.1, tmax=0.14)  # crop to window around peak

    cov = read_cov(fname_cov)
    cov = regularize(cov, evoked.info, rank=None)

    alpha = 0.5
    with catch_logging() as log:
        stc = gamma_map(evoked,
                        forward,
                        cov,
                        alpha,
                        tol=1e-4,
                        xyz_same_gamma=True,
                        update_mode=1,
                        verbose=True)
    _check_stc(stc, evoked, 68477, 'lh', fwd=forward)
    assert_var_exp_log(log.getvalue(), 20, 22)

    with catch_logging() as log:
        stc_vec, res = gamma_map(evoked,
                                 forward,
                                 cov,
                                 alpha,
                                 tol=1e-4,
                                 xyz_same_gamma=True,
                                 update_mode=1,
                                 pick_ori='vector',
                                 return_residual=True,
                                 verbose=True)
    assert_var_exp_log(log.getvalue(), 20, 22)
    assert_stcs_equal(stc_vec.magnitude(), stc)
    _check_stc(stc_vec, evoked, 68477, 'lh', fwd=forward, res=res)

    stc, res = gamma_map(evoked,
                         forward,
                         cov,
                         alpha,
                         tol=1e-4,
                         xyz_same_gamma=False,
                         update_mode=1,
                         pick_ori='vector',
                         return_residual=True)
    _check_stc(stc,
               evoked,
               82010,
               'lh',
               fwd=forward,
               dist_limit=6.,
               ratio=2.,
               res=res)

    with catch_logging() as log:
        dips = gamma_map(evoked,
                         forward,
                         cov,
                         alpha,
                         tol=1e-4,
                         xyz_same_gamma=False,
                         update_mode=1,
                         return_as_dipoles=True,
                         verbose=True)
    exp_var = assert_var_exp_log(log.getvalue(), 58, 60)
    dip_exp_var = np.mean(sum(dip.gof for dip in dips))
    assert_allclose(exp_var, dip_exp_var, atol=10)  # not really equiv, close
    assert (isinstance(dips[0], Dipole))
    stc_dip = make_stc_from_dipoles(dips, forward['src'])
    assert_stcs_equal(stc.magnitude(), stc_dip)

    # force fixed orientation
    stc, res = gamma_map(evoked,
                         forward,
                         cov,
                         alpha,
                         tol=1e-4,
                         xyz_same_gamma=False,
                         update_mode=2,
                         loose=0,
                         return_residual=True)
    _check_stc(stc, evoked, 85739, 'lh', fwd=forward, ratio=20., res=res)