def test_make_dics_rank(_load_forward, idx, whiten):
"""Test making DICS beamformer filters with rank param."""
_, fwd_surf, fwd_fixed, _ = _load_forward
epochs, _, csd, _, label, _, _ = _simulate_data(fwd_fixed, idx)
if whiten:
noise_csd, want_rank = _make_rand_csd(epochs.info, csd)
kind = 'mag + grad'
else:
noise_csd = None
epochs.pick_types(meg='grad')
want_rank = len(epochs.ch_names)
assert want_rank == 41
kind = 'grad'
with catch_logging() as log:
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
noise_csd=noise_csd,
verbose=True)
log = log.getvalue()
assert f'Estimated rank ({kind}): {want_rank}' in log, log
stc, _ = apply_dics_csd(csd, filters)
other_rank = want_rank - 1 # shouldn't make a huge difference
use_rank = dict(meg=other_rank)
if not whiten:
# XXX it's a bug that our rank functions don't treat "meg"
# properly here...
use_rank['grad'] = use_rank.pop('meg')
with catch_logging() as log:
filters_2 = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
noise_csd=noise_csd,
rank=use_rank,
verbose=True)
log = log.getvalue()
assert f'Computing rank from covariance with rank={use_rank}' in log, log
stc_2, _ = apply_dics_csd(csd, filters_2)
corr = np.corrcoef(stc_2.data.ravel(), stc.data.ravel())[0, 1]
assert 0.8 < corr < 0.99999
# degenerate conditions
if whiten:
# make rank deficient
data = noise_csd.get_data(0.)
data[0] = data[:0] = 0
noise_csd._data[:, 0] = _sym_mat_to_vector(data)
with pytest.raises(ValueError, match='meg data rank.*the noise rank'):
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
noise_csd=noise_csd,
verbose=True)
def test_real(_load_forward):
"""Test using a real-valued filter."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol, label = _load_forward
epochs, _, csd, source_vertno = _simulate_data(fwd_fixed)
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
rr_want = fwd_free['src'][0]['rr'][source_vertno]
epochs.pick_types('grad')
reg = 1 # Lots of regularization for our toy dataset
filters_real = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg,
real_filter=True)
# Also test here that no warings are thrown - implemented to check whether
# src should not be None warning occurs:
with pytest.warns(None) as w:
power, f = apply_dics_csd(csd, filters_real)
assert len(w) == 0
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test rank reduction
filters_real = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=5,
pick_ori='max-power',
inversion='matrix',
reduce_rank=True)
power, f = apply_dics_csd(csd, filters_real)
assert f == [10, 20]
idx = np.argmax(power.data[:, 1])
rr_got = fwd_free['src'][0]['rr'][vertices[idx]]
dist = np.linalg.norm(rr_got - rr_want)
assert dist <= 0.02
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test computing source power on a volume source space
filters_vol = make_dics(epochs.info, fwd_vol, csd, reg=reg)
power, f = apply_dics_csd(csd, filters_vol)
vol_source_ind = 3851 # FIXME: not make this hardcoded
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == vol_source_ind
assert power.data[vol_source_ind, 1] > power.data[vol_source_ind, 0]
# check whether a filters object without src_type throws expected warning
del filters_vol['src_type'] # emulate 0.16 behaviour to cause warning
with pytest.warns(RuntimeWarning,
match='spatial filter does not contain '
'src_type'):
apply_dics_csd(csd, filters_vol)
def test_real(_load_forward, idx, mat_tol, vol_tol):
"""Test using a real-valued filter."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol = _load_forward
epochs, _, csd, source_vertno, label, vertices, source_ind = \
_simulate_data(fwd_fixed, idx)
epochs.pick_types('grad')
reg = 1 # Lots of regularization for our toy dataset
filters_real = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg,
real_filter=True)
# Also test here that no warings are thrown - implemented to check whether
# src should not be None warning occurs:
with pytest.warns(None) as w:
power, f = apply_dics_csd(csd, filters_real)
assert len(w) == 0
assert f == [10, 20]
dist = _fwd_dist(power, fwd_surf, vertices, source_ind)
assert dist == 0
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test rank reduction
filters_real = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=5,
pick_ori='max-power',
inversion='matrix',
reduce_rank=True)
power, f = apply_dics_csd(csd, filters_real)
assert f == [10, 20]
dist = _fwd_dist(power, fwd_surf, vertices, source_ind)
assert dist == 0
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test computing source power on a volume source space
filters_vol = make_dics(epochs.info, fwd_vol, csd, reg=reg)
power, f = apply_dics_csd(csd, filters_vol)
vol_source_ind = _nearest_vol_ind(fwd_vol, fwd_surf, vertices, source_ind)
assert f == [10, 20]
dist = _fwd_dist(power, fwd_vol, fwd_vol['src'][0]['vertno'],
vol_source_ind)
assert dist <= vol_tol
assert power.data[vol_source_ind, 1] > power.data[vol_source_ind, 0]
# check whether a filters object without src_type throws expected warning
del filters_vol['src_type'] # emulate 0.16 behaviour to cause warning
with pytest.warns(RuntimeWarning,
match='spatial filter does not contain '
'src_type'):
apply_dics_csd(csd, filters_vol)
def test_apply_dics_ori_inv(_load_forward, pick_ori, inversion):
"""Testpicking different orientations and inversion modes."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol, label = _load_forward
epochs, _, csd, source_vertno = _simulate_data(fwd_fixed)
epochs.pick_types('grad')
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
rr_want = fwd_free['src'][0]['rr'][source_vertno]
reg_ = 5 if inversion == 'matrix' else 1
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg_,
pick_ori=pick_ori,
inversion=inversion,
normalize_fwd=False,
weight_norm='unit-noise-gain')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
idx = np.argmax(power.data[:, 1])
rr_got = fwd_free['src'][0]['rr'][vertices[idx]]
dist = np.linalg.norm(rr_got - rr_want)
assert dist <= (0.03 if inversion == 'matrix' else 0.)
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test unit-noise-gain weighting
csd_noise = csd.copy()
inds = np.triu_indices(csd.n_channels)
csd_noise._data[...] = np.eye(csd.n_channels)[inds][:, np.newaxis]
noise_power, f = apply_dics_csd(csd_noise, filters)
assert np.allclose(noise_power.data, 1)
# Test filter with forward normalization instead of weight
# normalization
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg_,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=None,
normalize_fwd=True)
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
idx = np.argmax(power.data[:, 1])
rr_got = fwd_free['src'][0]['rr'][vertices[idx]]
dist = np.linalg.norm(rr_got - rr_want)
assert dist <= (0.035 if inversion == 'matrix' else 0.)
assert power.data[source_ind, 1] > power.data[source_ind, 0]
def _gen_dics(active_win, baseline_win, epochs):
freqs = np.logspace(np.log10(12), np.log10(30), 9)
csd = csd_morlet(epochs, freqs, tmin=-1, tmax=1.5, decim=20)
csd_baseline = csd_morlet(epochs, freqs, tmin=baseline_win[0],
tmax=baseline_win[1], decim=20)
csd_ers = csd_morlet(epochs, freqs, tmin=active_win[0], tmax=active_win[1],
decim=20)
filters = make_dics(epochs.info, fwd, csd.mean(), pick_ori='max-power',
reduce_rank=True, real_filter=True)
stc_base, freqs = apply_dics_csd(csd_baseline.mean(), filters)
stc_act, freqs = apply_dics_csd(csd_ers.mean(), filters)
stc_act /= stc_base
return stc_act
def test_apply_dics_ori_inv(_load_forward, pick_ori, inversion, idx):
"""Test picking different orientations and inversion modes."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol = _load_forward
epochs, _, csd, source_vertno, label, vertices, source_ind = \
_simulate_data(fwd_fixed, idx)
epochs.pick_types(meg='grad')
reg_ = 5 if inversion == 'matrix' else 1
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg_,
pick_ori=pick_ori,
inversion=inversion,
depth=None,
weight_norm='unit-noise-gain')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
dist = _fwd_dist(power, fwd_surf, vertices, source_ind)
# This is 0. for unit-noise-gain-invariant:
assert dist <= (0.02 if inversion == 'matrix' else 0.)
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test unit-noise-gain weighting
csd_noise = csd.copy()
inds = np.triu_indices(csd.n_channels)
csd_noise._data[...] = np.eye(csd.n_channels)[inds][:, np.newaxis]
noise_power, f = apply_dics_csd(csd_noise, filters)
want_norm = 3 if pick_ori is None else 1.
assert_allclose(noise_power.data, want_norm, atol=1e-7)
# Test filter with forward normalization instead of weight
# normalization
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg_,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=None,
depth=1.)
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
dist = _fwd_dist(power, fwd_surf, vertices, source_ind)
mat_tol = {0: 0.055, 100: 0.20, 200: 0.015, 233: 0.035}[idx]
max_ = (mat_tol if inversion == 'matrix' else 0.)
assert 0 <= dist <= max_
assert power.data[source_ind, 1] > power.data[source_ind, 0]
def test_apply_dics_ori_inv(_load_forward, pick_ori, inversion, idx, mat_tol,
vol_tol):
"""Testpicking different orientations and inversion modes."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol = _load_forward
epochs, _, csd, source_vertno, label, vertices, source_ind = \
_simulate_data(fwd_fixed, idx)
epochs.pick_types('grad')
reg_ = 5 if inversion == 'matrix' else 1
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg_,
pick_ori=pick_ori,
inversion=inversion,
normalize_fwd=False,
weight_norm='unit-noise-gain')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
dist = _fwd_dist(power, fwd_surf, vertices, source_ind)
assert dist <= (0.03 if inversion == 'matrix' else 0.)
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test unit-noise-gain weighting
csd_noise = csd.copy()
inds = np.triu_indices(csd.n_channels)
csd_noise._data[...] = np.eye(csd.n_channels)[inds][:, np.newaxis]
noise_power, f = apply_dics_csd(csd_noise, filters)
assert np.allclose(noise_power.data, 1)
# Test filter with forward normalization instead of weight
# normalization
filters = make_dics(epochs.info,
fwd_surf,
csd,
label=label,
reg=reg_,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=None,
normalize_fwd=True)
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
dist = _fwd_dist(power, fwd_surf, vertices, source_ind)
max_ = (mat_tol if inversion == 'matrix' else 0.)
assert 0 <= dist <= max_
assert power.data[source_ind, 1] > power.data[source_ind, 0]
def test_apply_dics_csd(_load_forward, idx, inversion, weight_norm):
"""Test applying a DICS beamformer to a CSD matrix."""
fwd_free, fwd_surf, fwd_fixed, _ = _load_forward
epochs, _, csd, source_vertno, label, vertices, source_ind = \
_simulate_data(fwd_fixed, idx)
reg = 1 # Lots of regularization for our toy dataset
with pytest.raises(ValueError, match='several sensor types'):
make_dics(epochs.info, fwd_free, csd)
epochs.pick_types(meg='grad')
# Try different types of forward models
assert label.hemi == 'lh'
for fwd in [fwd_free, fwd_surf, fwd_fixed]:
filters = make_dics(epochs.info, fwd, csd, label=label, reg=reg,
inversion=inversion, weight_norm=weight_norm)
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
# Did we find the true source at 20 Hz?
dist = _fwd_dist(power, fwd_free, vertices, source_ind)
assert dist == 0.
# Is the signal stronger at 20 Hz than 10?
assert power.data[source_ind, 1] > power.data[source_ind, 0]
def test_apply_dics_csd(_load_forward):
"""Test applying a DICS beamformer to a CSD matrix."""
fwd_free, fwd_surf, fwd_fixed, _, label = _load_forward
epochs, _, csd, source_vertno = _simulate_data(fwd_fixed)
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
reg = 1 # Lots of regularization for our toy dataset
with pytest.raises(RuntimeError, match='several sensor types'):
make_dics(epochs.info, fwd_free, csd)
epochs.pick_types(meg='grad')
# Try different types of forward models
assert label.hemi == 'lh'
assert vertices[source_ind] == source_vertno
rr_want = fwd_free['src'][0]['rr'][source_vertno]
for fwd in [fwd_free, fwd_surf, fwd_fixed]:
filters = make_dics(epochs.info,
fwd,
csd,
label=label,
reg=reg,
inversion='single')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
# Did we find the true source at 20 Hz?
idx = np.argmax(power.data[:, 1])
rr_got = fwd_free['src'][0]['rr'][vertices[idx]]
dist = np.linalg.norm(rr_got - rr_want)
assert dist == 0.
# Is the signal stronger at 20 Hz than 10?
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Set picks
picks = mne.pick_types(raw.info, meg=True, eeg=False, eog=False,
stim=False, exclude='bads')
# Read epochs
event_id, tmin, tmax = 1, -0.2, 0.5
events = mne.read_events(event_fname)
epochs = mne.Epochs(raw, events, event_id, tmin, tmax, proj=True,
picks=picks, baseline=(None, 0), preload=True,
reject=dict(grad=4000e-13, mag=4e-12))
evoked = epochs.average()
# Read forward operator
forward = mne.read_forward_solution(fname_fwd)
###############################################################################
# Computing the cross-spectral density matrix at 4 evenly spaced frequencies
# from 6 to 10 Hz. We use a decim value of 20 to speed up the computation in
# this example at the loss of accuracy.
csd = csd_morlet(epochs, tmin=0, tmax=0.5, decim=20,
frequencies=np.linspace(6, 10, 4))
# Compute DICS spatial filter and estimate source power.
filters = make_dics(epochs.info, forward, csd, reg=0.5)
stc, freqs = apply_dics_csd(csd, filters)
message = 'DICS source power in the 8-12 Hz frequency band'
brain = stc.plot(surface='inflated', hemi='rh', subjects_dir=subjects_dir,
time_label=message)
def test_tf_dics():
"""Test 5D time-frequency beamforming based on DICS."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol, label = _load_forward()
epochs, evoked, _, source_vertno = _simulate_data(fwd_fixed)
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
reg = 1 # Lots of regularization for our toy dataset
tmin = 0
tmax = 9
tstep = 4
win_lengths = [5, 5]
frequencies = [10, 20]
freq_bins = [(8, 12), (18, 22)]
# Compute DICS for two time windows and two frequencies
for mode in ['fourier', 'multitaper', 'cwt_morlet']:
stcs = tf_dics(epochs, fwd_surf, None, tmin, tmax, tstep, win_lengths,
mode=mode, freq_bins=freq_bins, frequencies=frequencies,
decim=10, reg=reg, label=label)
# Did we find the true source at 20 Hz?
assert np.argmax(stcs[1].data[:, 0]) == source_ind
assert np.argmax(stcs[1].data[:, 1]) == source_ind
# 20 Hz power should decrease over time
assert stcs[1].data[source_ind, 0] > stcs[1].data[source_ind, 1]
# 20 Hz power should be more than 10 Hz power at the true source
assert stcs[1].data[source_ind, 0] > stcs[0].data[source_ind, 0]
# Manually compute source power and compare with the last tf_dics result.
source_power = []
time_windows = [(0, 5), (4, 9)]
for time_window in time_windows:
csd = csd_morlet(epochs, frequencies=[frequencies[1]],
tmin=time_window[0], tmax=time_window[1], decim=10)
csd = csd.sum()
csd._data /= csd.n_fft
filters = make_dics(epochs.info, fwd_surf, csd, reg=reg, label=label)
stc_source_power, _ = apply_dics_csd(csd, filters)
source_power.append(stc_source_power.data)
# Comparing tf_dics results with dics_source_power results
assert_allclose(stcs[1].data, np.array(source_power).squeeze().T, atol=0)
# Test using noise csds. We're going to use identity matrices. That way,
# since we're using unit-noise-gain weight normalization, there should be
# no effect.
stcs = tf_dics(epochs, fwd_surf, None, tmin, tmax, tstep, win_lengths,
mode='cwt_morlet', frequencies=frequencies, decim=10,
reg=reg, label=label, normalize_fwd=False,
weight_norm='unit-noise-gain')
noise_csd = csd.copy()
inds = np.triu_indices(csd.n_channels)
# Using [:, :] syntax for in-place broadcasting
noise_csd._data[:, :] = 2 * np.eye(csd.n_channels)[inds][:, np.newaxis]
noise_csd.n_fft = 2 # Dividing by n_fft should yield an identity CSD
noise_csds = [noise_csd, noise_csd] # Two frequency bins
stcs_norm = tf_dics(epochs, fwd_surf, noise_csds, tmin, tmax, tstep,
win_lengths, mode='cwt_morlet',
frequencies=frequencies, decim=10, reg=reg,
label=label, normalize_fwd=False,
weight_norm='unit-noise-gain')
assert_allclose(stcs_norm[0].data, stcs[0].data, atol=0)
assert_allclose(stcs_norm[1].data, stcs[1].data, atol=0)
# Test invalid parameter combinations
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths, mode='fourier', freq_bins=None)
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths, mode='cwt_morlet', frequencies=None)
# Test if incorrect number of noise CSDs is detected
raises(ValueError, tf_dics, epochs, fwd_surf, [noise_csds[0]], tmin, tmax,
tstep, win_lengths, freq_bins=freq_bins)
# Test if freq_bins and win_lengths incompatibility is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths=[0, 1, 2], freq_bins=freq_bins)
# Test if time step exceeding window lengths is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep=0.15,
win_lengths=[0.2, 0.1], freq_bins=freq_bins)
# Test if incorrent number of n_ffts is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths, freq_bins=freq_bins, n_ffts=[1])
# Test if incorrect number of mt_bandwidths is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths=win_lengths, freq_bins=freq_bins, mode='multitaper',
mt_bandwidths=[20])
# Test if subtracting evoked responses yields NaN's, since we only have one
# epoch. Suppress division warnings.
with pytest.warns(RuntimeWarning, match='[invalid|empty]'):
stcs = tf_dics(epochs, fwd_surf, None, tmin, tmax, tstep, win_lengths,
mode='cwt_morlet', frequencies=frequencies,
subtract_evoked=True, reg=reg, label=label, decim=20)
assert np.all(np.isnan(stcs[0].data))
def test_apply_dics_csd():
"""Test applying a DICS beamformer to a CSD matrix."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol, label = _load_forward()
epochs, _, csd, source_vertno = _simulate_data(fwd_fixed)
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
reg = 1 # Lots of regularization for our toy dataset
# Construct an identity "noise" CSD, which we will use to test the
# 'unit-noise-gain' setting.
csd_noise = csd.copy()
inds = np.triu_indices(csd.n_channels)
# Using [:, :] syntax for in-place broadcasting
csd_noise._data[:, :] = np.eye(csd.n_channels)[inds][:, np.newaxis]
# Try different types of forward models
for fwd in [fwd_free, fwd_surf, fwd_fixed]:
filters = make_dics(epochs.info, fwd, csd, label=label, reg=reg,
inversion='single')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
# Did we find the true source at 20 Hz?
assert np.argmax(power.data[:, 1]) == source_ind
# Is the signal stronger at 20 Hz than 10?
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Try picking different orientations and inversion modes
for pick_ori in [None, 'normal', 'max-power']:
for inversion in ['single', 'matrix']:
# Matrix inversion mode needs more regularization for this toy
# dataset.
if inversion == 'matrix':
reg_ = 5
else:
reg_ = reg
filters = make_dics(epochs.info, fwd_surf, csd, label=label,
reg=reg_, pick_ori=pick_ori,
inversion=inversion,
weight_norm='unit-noise-gain')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test unit-noise-gain weighting
noise_power, f = apply_dics_csd(csd_noise, filters)
assert np.allclose(noise_power.data, 1)
# Test filter with forward normalization instead of weight
# normalization
filters = make_dics(epochs.info, fwd_surf, csd, label=label,
reg=reg_, pick_ori=pick_ori,
inversion=inversion, weight_norm=None,
normalize_fwd=True)
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test using a real-valued filter
filters_real = make_dics(epochs.info, fwd_surf, csd, label=label, reg=reg,
real_filter=True)
# Also test here that no warings are thrown - implemented to check whether
# src should not be None warning occurs:
with pytest.warns(None) as w:
power, f = apply_dics_csd(csd, filters_real)
assert len(w) == 0
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test rank reduction
filters_real = make_dics(epochs.info, fwd_surf, csd, label=label, reg=5,
pick_ori='max-power', inversion='matrix',
reduce_rank=True)
power, f = apply_dics_csd(csd, filters_real)
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test computing source power on a volume source space
filters_vol = make_dics(epochs.info, fwd_vol, csd, reg=reg)
power, f = apply_dics_csd(csd, filters_vol)
vol_source_ind = 3851 # FIXME: not make this hardcoded
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == vol_source_ind
assert power.data[vol_source_ind, 1] > power.data[vol_source_ind, 0]
# check whether a filters object without src_type throws expected warning
del filters_vol['src_type'] # emulate 0.16 behaviour to cause warning
with pytest.warns(RuntimeWarning, match='spatial filter does not contain '
'src_type'):
apply_dics_csd(csd, filters_vol)
csd_pos_gamma = csd_pos_gamma.mean()
# csd_rest_alpha = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_rest_alpha.h5".format(dir=meg_dir,meg=meg))
# csd_rest_theta = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_rest_theta.h5".format(dir=meg_dir,meg=meg))
# csd_rest_beta_low = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_rest_beta_low.h5".format(dir=meg_dir,meg=meg))
# csd_rest_beta_high = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_rest_beta_high.h5".format(dir=meg_dir,meg=meg))
# csd_rest_gamma = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_rest_gamma.h5".format(dir=meg_dir,meg=meg))
# make DICS beamformers / filters (common filters) for different freq bands
filters_exp_alpha = make_dics(epo_exp.info,fwd_exp,csd_exp_alpha,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
filters_exp_theta = make_dics(epo_exp.info,fwd_exp,csd_exp_theta,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
filters_exp_beta_low = make_dics(epo_exp.info,fwd_exp,csd_exp_beta_low,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
filters_exp_beta_high = make_dics(epo_exp.info,fwd_exp,csd_exp_beta_high,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
filters_exp_gamma = make_dics(epo_exp.info,fwd_exp,csd_exp_gamma,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
# apply the DICS beamformers to get source Estimates for ton, neg, pos using common filters & save to file
stc_ton_alpha, freqs_ton_alpha = apply_dics_csd(csd_ton_alpha,filters_exp_alpha)
stc_ton_theta, freqs_ton_theta = apply_dics_csd(csd_ton_theta,filters_exp_theta)
stc_ton_beta_low, freqs_ton_beta_low = apply_dics_csd(csd_ton_beta_low,filters_exp_beta_low)
stc_ton_beta_high, freqs_ton_beta_high = apply_dics_csd(csd_ton_beta_high,filters_exp_beta_high)
stc_ton_gamma, freqs_ton_gamma = apply_dics_csd(csd_ton_gamma,filters_exp_gamma)
stc_ton_alpha.save(fname=meg_dir+"nc_{}_stc_ton_alpha".format(meg))
stc_ton_theta.save(fname=meg_dir+"nc_{}_stc_ton_theta".format(meg))
stc_ton_beta_low.save(fname=meg_dir+"nc_{}_stc_ton_beta_low".format(meg))
stc_ton_beta_high.save(fname=meg_dir+"nc_{}_stc_ton_beta_high".format(meg))
stc_ton_gamma.save(fname=meg_dir+"nc_{}_stc_ton_gamma".format(meg))
stc_neg_alpha, freqs_neg_alpha = apply_dics_csd(csd_neg_alpha,filters_exp_alpha)
stc_neg_theta, freqs_neg_theta = apply_dics_csd(csd_neg_theta,filters_exp_theta)
stc_neg_beta_low, freqs_neg_beta_low = apply_dics_csd(csd_neg_beta_low,filters_exp_beta_low)
stc_neg_beta_high, freqs_neg_beta_high = apply_dics_csd(csd_neg_beta_high,filters_exp_beta_high)
stc_neg_gamma, freqs_neg_gamma = apply_dics_csd(csd_neg_gamma,filters_exp_gamma)
csd_ton = mne.time_frequency.read_csd(
"{dir}nc_{meg}-csd_ton_{freq}.h5".format(dir=meg_dir,
meg=meg,
freq=freq))
# make DICS beamformers / filters (common filters)
filters_bas = make_dics(epo_bas.info,
fwd_base,
csd_bas,
pick_ori='max-power',
rank=None,
inversion='single',
weight_norm=None,
normalize_fwd=True,
real_filter=False)
# apply the DICS beamformers to get source Estimates for rest,ton using common filters & save to file
stc_rest, freqs_rest = apply_dics_csd(csd_rest, filters_bas)
stc_ton, freqs_ton = apply_dics_csd(csd_ton, filters_bas)
# calculate the difference of each condition to the tone baseline & save to file
stc_tonbas_diff = (stc_ton - stc_rest) / stc_rest
# morph the resulting stcs to fsaverage & save (to be loaded again and averaged)
morph = mne.compute_source_morph(stc_tonbas_diff,
subject_from=mri,
subject_to="fsaverage",
subjects_dir=mri_dir)
stc_fs_tonbas_diff = morph.apply(stc_tonbas_diff)
stc_fs_tonbas_diff.save(
fname=meg_dir + "nc_{}_stc_fs_tonbas_diff_F_{}".format(meg, freq))
# prepare for source diff permutation t-test
src = mne.read_source_spaces("{}fsaverage_ico5-src.fif".format(meg_dir))
connectivity = mne.spatial_src_connectivity(src)
def test_tf_dics(_load_forward, idx, mat_tol, vol_tol):
"""Test 5D time-frequency beamforming based on DICS."""
fwd_free, fwd_surf, fwd_fixed, _ = _load_forward
epochs, _, _, source_vertno, label, vertices, source_ind = \
_simulate_data(fwd_fixed, idx)
reg = 1 # Lots of regularization for our toy dataset
tmin = 0
tmax = 9
tstep = 4
win_lengths = [5, 5]
frequencies = [10, 20]
freq_bins = [(8, 12), (18, 22)]
with pytest.raises(RuntimeError, match='several sensor types'):
stcs = tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
freq_bins=freq_bins,
frequencies=frequencies,
decim=10,
reg=reg,
label=label)
epochs.pick_types(meg='grad')
# Compute DICS for two time windows and two frequencies
for mode in ['fourier', 'multitaper', 'cwt_morlet']:
stcs = tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
mode=mode,
freq_bins=freq_bins,
frequencies=frequencies,
decim=10,
reg=reg,
label=label)
# Did we find the true source at 20 Hz?
dist = _fwd_dist(stcs[1], fwd_surf, vertices, source_ind, tidx=0)
assert dist == 0
dist = _fwd_dist(stcs[1], fwd_surf, vertices, source_ind, tidx=1)
assert dist == 0
# 20 Hz power should decrease over time
assert stcs[1].data[source_ind, 0] > stcs[1].data[source_ind, 1]
# 20 Hz power should be more than 10 Hz power at the true source
assert stcs[1].data[source_ind, 0] > stcs[0].data[source_ind, 0]
# Manually compute source power and compare with the last tf_dics result.
source_power = []
time_windows = [(0, 5), (4, 9)]
for time_window in time_windows:
csd = csd_morlet(epochs,
frequencies=[frequencies[1]],
tmin=time_window[0],
tmax=time_window[1],
decim=10)
csd = csd.sum()
csd._data /= csd.n_fft
filters = make_dics(epochs.info, fwd_surf, csd, reg=reg, label=label)
stc_source_power, _ = apply_dics_csd(csd, filters)
source_power.append(stc_source_power.data)
# Comparing tf_dics results with dics_source_power results
assert_allclose(stcs[1].data, np.array(source_power).squeeze().T, atol=0)
# Test using noise csds. We're going to use identity matrices. That way,
# since we're using unit-noise-gain weight normalization, there should be
# no effect.
stcs = tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
mode='cwt_morlet',
frequencies=frequencies,
decim=10,
reg=reg,
label=label,
normalize_fwd=False,
weight_norm='unit-noise-gain')
noise_csd = csd.copy()
inds = np.triu_indices(csd.n_channels)
# Using [:, :] syntax for in-place broadcasting
noise_csd._data[:, :] = 2 * np.eye(csd.n_channels)[inds][:, np.newaxis]
noise_csd.n_fft = 2 # Dividing by n_fft should yield an identity CSD
noise_csds = [noise_csd, noise_csd] # Two frequency bins
stcs_norm = tf_dics(epochs,
fwd_surf,
noise_csds,
tmin,
tmax,
tstep,
win_lengths,
mode='cwt_morlet',
frequencies=frequencies,
decim=10,
reg=reg,
label=label,
normalize_fwd=False,
weight_norm='unit-noise-gain')
assert_allclose(stcs_norm[0].data, stcs[0].data, atol=0)
assert_allclose(stcs_norm[1].data, stcs[1].data, atol=0)
# Test invalid parameter combinations
with pytest.raises(ValueError, match='fourier.*freq_bins" parameter'):
tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
mode='fourier',
freq_bins=None)
with pytest.raises(ValueError, match='cwt_morlet.*frequencies" param'):
tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
mode='cwt_morlet',
frequencies=None)
# Test if incorrect number of noise CSDs is detected
with pytest.raises(ValueError, match='One noise CSD object expected per'):
tf_dics(epochs,
fwd_surf, [noise_csds[0]],
tmin,
tmax,
tstep,
win_lengths,
freq_bins=freq_bins)
# Test if freq_bins and win_lengths incompatibility is detected
with pytest.raises(ValueError, match='One time window length expected'):
tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths=[0, 1, 2],
freq_bins=freq_bins)
# Test if time step exceeding window lengths is detected
with pytest.raises(ValueError, match='Time step should not be larger'):
tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep=0.15,
win_lengths=[0.2, 0.1],
freq_bins=freq_bins)
# Test if incorrect number of n_ffts is detected
with pytest.raises(ValueError, match='When specifying number of FFT'):
tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
freq_bins=freq_bins,
n_ffts=[1])
# Test if incorrect number of mt_bandwidths is detected
with pytest.raises(ValueError, match='When using multitaper mode and'):
tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths=win_lengths,
freq_bins=freq_bins,
mode='multitaper',
mt_bandwidths=[20])
# Test if subtracting evoked responses yields NaN's, since we only have one
# epoch. Suppress division warnings.
assert len(epochs) == 1, len(epochs)
with np.errstate(invalid='ignore'):
stcs = tf_dics(epochs,
fwd_surf,
None,
tmin,
tmax,
tstep,
win_lengths,
mode='cwt_morlet',
frequencies=frequencies,
subtract_evoked=True,
reg=reg,
label=label,
decim=20)
assert np.all(np.isnan(stcs[0].data))
info = epochs_joint.info
else:
raise ValueError('Invalid sensor type: %s', sensor_type)
filters = make_dics(info,
fwd_disc_man,
csd,
reg=reg,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=weight_norm,
noise_csd=noise_csd if use_noise_cov else None,
normalize_fwd=normalize_fwd,
real_filter=real_filter,
reduce_rank=reduce_rank)
stc_est_power, freqs = apply_dics_csd(csd, filters)
peak_vertex, _ = stc_est_power.get_peak(vert_as_index=True)
# Compute distance between true and estimated source locations
pos_est = fwd_disc_man['source_rr'][peak_vertex]
pos_true = fwd_disc_man['source_rr'][config.vertex]
dist = np.linalg.norm(pos_est - pos_true)
# Ratio between estimated peak activity and all estimated activity.
focality_score = stc_est_power.data[peak_vertex,
0] / stc_est_power.data.sum()
if pick_ori == 'max-power':
estimated_ori = filters['max_power_oris'][0][config.vertex]
ori_error = np.rad2deg(abs(np.arccos(estimated_ori @ true_ori)))
raise ValueError('Invalid sensor type: %s', sensor_type)
# Allow using other MNE branches without this arg
use_kwargs = dict(noise_csd=noise_csd) if use_noise_cov else dict()
filters = make_dics(info,
fwd_disc_man,
csd if use_noise_cov else signal_csd,
reg=reg,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=weight_norm,
depth=1. if normalize_fwd else None,
real_filter=real_filter,
reduce_rank=reduce_rank,
**use_kwargs)
stc_est_power, freqs = apply_dics_csd(signal_csd, filters)
stc_noise_power, freqs = apply_dics_csd(noise_csd, filters)
peak_vertex, _ = stc_est_power.get_peak(vert_as_index=True)
# Compute distance between true and estimated source locations
pos_est = fwd_disc_man['source_rr'][peak_vertex]
pos_true = fwd_disc_man['source_rr'][config.vertex]
dist = np.linalg.norm(pos_est - pos_true)
# Ratio between estimated peak activity and all estimated activity.
focality_score = stc_est_power.data[peak_vertex,
0] / stc_est_power.data.sum()
if pick_ori == 'max-power':
estimated_ori = filters['max_power_ori'][0][config.vertex]
def test_apply_dics_csd():
"""Test applying a DICS beamformer to a CSD matrix."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol, label = _load_forward()
epochs, _, csd, source_vertno = _simulate_data(fwd_fixed)
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
reg = 1 # Lots of regularization for our toy dataset
# Construct an identity "noise" CSD, which we will use to test the
# 'unit-noise-gain' setting.
csd_noise = csd.copy()
inds = np.triu_indices(csd.n_channels)
# Using [:, :] syntax for in-place broadcasting
csd_noise._data[:, :] = np.eye(csd.n_channels)[inds][:, np.newaxis]
# Try different types of forward models
for fwd in [fwd_free, fwd_surf, fwd_fixed]:
filters = make_dics(epochs.info, fwd, csd, label=label, reg=reg,
inversion='single')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
# Did we find the true source at 20 Hz?
assert np.argmax(power.data[:, 1]) == source_ind
# Is the signal stronger at 20 Hz than 10?
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Try picking different orientations and inversion modes
for pick_ori in [None, 'normal', 'max-power']:
for inversion in ['single', 'matrix']:
# Matrix inversion mode needs more regularization for this toy
# dataset.
if inversion == 'matrix':
reg_ = 5
else:
reg_ = reg
filters = make_dics(epochs.info, fwd_surf, csd, label=label,
reg=reg_, pick_ori=pick_ori,
inversion=inversion,
weight_norm='unit-noise-gain')
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test unit-noise-gain weighting
noise_power, f = apply_dics_csd(csd_noise, filters)
assert np.allclose(noise_power.data, 1)
# Test filter with forward normalization instead of weight
# normalization
filters = make_dics(epochs.info, fwd_surf, csd, label=label,
reg=reg_, pick_ori=pick_ori,
inversion=inversion, weight_norm=None,
normalize_fwd=True)
power, f = apply_dics_csd(csd, filters)
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test using a real-valued filter
filters_real = make_dics(epochs.info, fwd_surf, csd, label=label, reg=reg,
real_filter=True)
# Also test here that no warings are thrown - implemented to check whether
# src should not be None warning occurs:
with pytest.warns(None) as w:
power, f = apply_dics_csd(csd, filters_real)
assert len(w) == 0
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test rank reduction
filters_real = make_dics(epochs.info, fwd_surf, csd, label=label, reg=5,
pick_ori='max-power', inversion='matrix',
reduce_rank=True)
power, f = apply_dics_csd(csd, filters_real)
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == source_ind
assert power.data[source_ind, 1] > power.data[source_ind, 0]
# Test computing source power on a volume source space
filters_vol = make_dics(epochs.info, fwd_vol, csd, reg=reg)
power, f = apply_dics_csd(csd, filters_vol)
vol_source_ind = 3851 # FIXME: not make this hardcoded
assert f == [10, 20]
assert np.argmax(power.data[:, 1]) == vol_source_ind
assert power.data[vol_source_ind, 1] > power.data[vol_source_ind, 0]
# check whether a filters object without src_type throws expected warning
del filters_vol['src_type'] # emulate 0.16 behaviour to cause warning
with pytest.warns(RuntimeWarning, match='spatial filter does not contain '
'src_type'):
apply_dics_csd(csd, filters_vol)
# stc.save("{a}stcs/nc_{b}_{c}_{f0}-{f1}Hz_{d}_{sp}".format(
# a=proc_dir, b=sub, c=epo_name, f0=f[0], f1=f[-1],
# d=event, sp=spacing))
# now byresp epo
for run in ["audio", "visual", "visselten"]:
epo_name = "{dir}{sub}_{run}_byresp-epo.fif".format(dir=proc_dir,
sub=sub,
run=run)
epo = mne.read_epochs(epo_name)
for event in range(len(epo)):
print(event)
event_csd = csd_morlet(epo[event],
frequencies=freqs,
n_jobs=n_jobs,
n_cycles=7,
decim=3)
stc, freqs = apply_dics_csd(event_csd, filters)
del event_csd
stc.expand([s["vertno"] for s in src])
stc.subject = sub
stc.save(
"{a}stcs/nc_{b}_{c}_byresp_{f0}-{f1}Hz_{d}_{sp}".format(
a=proc_dir,
b=sub,
c=run,
f0=f[0],
f1=f[-1],
d=event,
sp=spacing))
info = epochs_grad.info
elif sensor_type == 'mag':
info = epochs_mag.info
else:
raise ValueError('Invalid sensor type: %s', sensor_type)
filters = make_dics(info,
fwd,
csd,
reg=reg,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=weight_norm,
normalize_fwd=normalize_fwd,
real_filter=real_filter)
stc, freqs = apply_dics_csd(csd, filters)
# Compute distance between true and estimated source
dip_true = make_dipole(stc_signal, fwd['src'])
dip_est = make_dipole(stc, fwd['src'])
dist = np.linalg.norm(dip_true.pos - dip_est.pos)
# Fancy evaluation metric
ev = evaluate_stc(stc, stc_signal)
except Exception as e:
print(e)
dist = np.nan
ev = np.nan
print(setting, dist, ev)
dists.append(dist)
csd_pos_gamma_high = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_pos_gamma_high.h5".format(dir=meg_dir,meg=meg))
csd_pos_gamma_high = csd_pos_gamma_high.mean()
csd_rest_gamma_high = mne.time_frequency.read_csd("{dir}nc_{meg}-csd_rest_gamma_high.h5".format(dir=meg_dir,meg=meg))
csd_rest_gamma_high = csd_rest_gamma_high.mean()
# build DICS filters
# for experimental conditions analyses
filters_exp_gamma_high = make_dics(epo_exp.info,fwd_exp,csd_exp_gamma_high,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
# clean memory
del epo_exp, fwd_exp, csd_exp_gamma_high
# for baseline analyses
filters_bas_gamma_high = make_dics(epo_bas.info,fwd_base,csd_bas_gamma_high,pick_ori='max-power',rank=None,inversion='single',weight_norm=None,normalize_fwd=True,real_filter=False)
# clean memory
del epo_bas, fwd_base, csd_bas_gamma_high
# apply filters, calculate difference stcs & save
# for experiment
stc_ton_gamma_high, freqs_ton_gamma_high = apply_dics_csd(csd_ton_gamma_high,filters_exp_gamma_high)
stc_neg_gamma_high, freqs_neg_gamma_high = apply_dics_csd(csd_neg_gamma_high,filters_exp_gamma_high)
stc_pos_gamma_high, freqs_pos_gamma_high = apply_dics_csd(csd_pos_gamma_high,filters_exp_gamma_high)
stc_diff_gamma_high = (stc_neg_gamma_high - stc_pos_gamma_high) / stc_ton_gamma_high
stc_diff_gamma_high.save(fname=meg_dir+"nc_{}_stc_limb_mix_diff_gamma_high".format(meg))
# clean memory
del filters_exp_gamma_high, csd_neg_gamma_high, csd_pos_gamma_high
# for baseline
stc_ton_gamma_high, freqs_ton_gamma_high = apply_dics_csd(csd_ton_gamma_high,filters_bas_gamma_high)
stc_rest_gamma_high, freqs_rest_gamma_high = apply_dics_csd(csd_rest_gamma_high,filters_bas_gamma_high)
stc_tonbas_gamma_high = (stc_ton_gamma_high - stc_rest_gamma_high) / stc_rest_gamma_high
stc_tonbas_gamma_high.save(fname=meg_dir+"nc_{}_stc_limb_mix_tonbas_gamma_high".format(meg))
# clean memory
del filters_bas_gamma_high, csd_rest_gamma_high, csd_ton_gamma_high
del stc_rest_gamma_high, stc_ton_gamma_high, stc_neg_gamma_high, stc_pos_gamma_high
# read mixed source space
# Read the info structure
info = mne.io.read_info(fname.epo(subject=subject))
# Compute source power for all frequency bands and all conditions
fmin = [f[0] for f in freq_bands]
fmax = [f[1] for f in freq_bands]
csds = dict()
for condition in conditions + ['baseline']:
print('Reading CSD matrix for condition:', condition)
# Read the CSD matrix
csds[condition] = read_csd(fname.csd(condition=condition, subject=subject))
# Average the CSDs of both conditions
csd = csds['face'].copy()
csd._data += csds['scrambled']._data
csd._data /= 2
# Compute the DICS beamformer using the CSDs from both conditions, for all
# frequency bands.
filters = make_dics(info=info, forward=fwd, csd=csd.mean(fmin, fmax), reg=reg,
pick_ori='max-power')
stcs = dict()
for condition in conditions + ['baseline']:
print('Computing power for condition:', condition)
stcs[condition], _ = apply_dics_csd(csds[condition].mean(fmin, fmax),
filters)
stcs[condition].save(fname.power(condition=condition, subject=subject))
# Rotate the view and add a title.
mlab.view(0, 0, 550, [0, 0, 0])
mlab.title('MNE-dSPM inverse (RMS)', height=0.9)
###############################################################################
# Computing a cortical power map at 10 Hz. using a DICS beamformer:
# Estimate the cross-spectral density (CSD) matrix on the trial containing the
# signal.
csd_signal = csd_morlet(epochs['signal'], frequencies=[10])
# Compute the DICS powermap. For this simulated dataset, we need a lot of
# regularization for the beamformer to behave properly. For real recordings,
# this amount of regularization is probably too much.
filters = make_dics(epochs.info, fwd, csd_signal, reg=1, pick_ori='max-power')
power, f = apply_dics_csd(csd_signal, filters)
# Plot the DICS power map.
brain = power.plot('sample',
subjects_dir=subjects_dir,
hemi='both',
figure=2,
size=400)
# Indicate the true locations of the source activity on the plot.
brain.add_foci(source_vert1, coords_as_verts=True, hemi='lh')
brain.add_foci(source_vert2, coords_as_verts=True, hemi='rh')
# Rotate the view and add a title.
mlab.view(0, 0, 550, [0, 0, 0])
mlab.title('DICS power map at %.1f Hz' % f[0], height=0.9)
info_eq, fwd_eq, csd_eq = mne.channels.equalize_channels(
[info, fwd, csd])
filters = make_dics(info_eq,
fwd_eq,
csd_eq,
reg=reg,
pick_ori=pick_ori,
inversion=inversion,
weight_norm=weight_norm,
noise_csd=csd_baseline if use_noise_cov else None,
normalize_fwd=normalize_fwd,
real_filter=real_filter,
reduce_rank=reduce_rank)
# Compute source power
stc_baseline, _ = apply_dics_csd(csd_baseline, filters)
stc_power, _ = apply_dics_csd(csd_ers, filters)
# Normalize with baseline power.
stc_power /= stc_baseline
stc_power.data = np.log(stc_power.data)
peak_vertex, _ = stc_power.get_peak(vert_as_index=True)
# Compute distance between true and estimated source locations
pos = fwd['source_rr'][peak_vertex]
dist = np.linalg.norm(dip.pos - pos)
# Ratio between estimated peak activity and all estimated activity.
focality_score = stc_power.data[peak_vertex, 0] / stc_power.data.sum()
filters_approach2 = make_dics(info,
fwd,
csd_signal,
reg=0.1,
pick_ori='max-power',
normalize_fwd=False,
inversion='matrix',
weight_norm='unit-noise-gain')
print(filters_approach2)
# You can save these to disk with:
# filters_approach1.save('filters_1-dics.h5')
# Compute the DICS power map by applying the spatial filters to the CSD matrix.
power_approach1, f = apply_dics_csd(csd_signal, filters_approach1)
power_approach2, f = apply_dics_csd(csd_signal, filters_approach2)
# Plot the DICS power maps for both approaches.
for approach, power in enumerate([power_approach1, power_approach2], 1):
brain = power.plot('sample',
subjects_dir=subjects_dir,
hemi='both',
figure=approach + 1,
size=600)
# Indicate the true locations of the source activity on the plot.
brain.add_foci(source_vert1, coords_as_verts=True, hemi='lh')
brain.add_foci(source_vert2, coords_as_verts=True, hemi='rh')
# Rotate the view and add a title.
fwd_b,
csd,
pick_ori=None,
rank='full',
weight_norm=None,
normalize_fwd=False,
real_filter=False)
neg_a = epo_a["negative"]
neg_b = epo_b["negative"]
pos_a = epo_a["positive"]
pos_b = epo_b["positive"]
# csd_pos_a = csd_morlet(pos, frequencies=freqs, n_jobs=8, n_cycles=9, decim=3)
# csd_neg_a = csd_morlet(neg, frequencies=freqs, n_jobs=8, n_cycles=9, decim=3)
csd_pos_a = csd_multitaper(pos_a, fmin=7, fmax=14, bandwidth=1)
stc_pos_a, freqs_pos_a = apply_dics_csd(
csd_pos_a, filters_a
) # in mne tutorial they use csd.mean() for the whole freq band
csd_pos_b = csd_multitaper(pos_b, fmin=7, fmax=14, bandwidth=1)
stc_pos_b, freqs_pos_b = apply_dics_csd(csd_pos_b, filters_b)
csd_neg_a = csd_multitaper(neg_a, fmin=7, fmax=14, bandwidth=1)
stc_neg_a, freqs_neg_a = apply_dics_csd(
csd_neg_a, filters_a
) # in mne tutorial they use csd.mean() for the whole freq band
csd_neg_b = csd_multitaper(neg_b, fmin=7, fmax=14, bandwidth=1)
stc_neg_b, freqs_neg_b = apply_dics_csd(csd_neg_b, filters_b)
stc_pos = (stc_pos_a + stc_pos_b) / 2
stc_neg = (stc_neg_a + stc_neg_b) / 2
stc_diff = stc_neg - stc_pos
# plot the difference between conditions
stc_diff.plot(subjects_dir=mri_dir,
subject=mri,
# We are interested in the beta band. Define a range of frequencies, using a
# log scale, from 12 to 30 Hz.
freqs = np.logspace(np.log10(12), np.log10(30), 9)
###############################################################################
# Computing the cross-spectral density matrix for the beta frequency band, for
# different time intervals. We use a decim value of 20 to speed up the
# computation in this example at the loss of accuracy.
csd = csd_morlet(epochs, freqs, tmin=-1, tmax=1.5, decim=20)
csd_baseline = csd_morlet(epochs, freqs, tmin=-1, tmax=0, decim=20)
# ERS activity starts at 0.5 seconds after stimulus onset
csd_ers = csd_morlet(epochs, freqs, tmin=0.5, tmax=1.5, decim=20)
###############################################################################
# Computing DICS spatial filters using the CSD that was computed on the entire
# timecourse.
filters = make_dics(epochs.info, fwd, csd.mean(), pick_ori='max-power')
###############################################################################
# Applying DICS spatial filters separately to the CSD computed using the
# baseline and the CSD computed during the ERS activity.
baseline_source_power, freqs = apply_dics_csd(csd_baseline.mean(), filters)
beta_source_power, freqs = apply_dics_csd(csd_ers.mean(), filters)
###############################################################################
# Visualizing source power during ERS activity relative to the baseline power.
stc = beta_source_power / baseline_source_power
message = 'DICS source power in the 12-30 Hz frequency band'
brain = stc.plot(hemi='both', views='par', subjects_dir=subjects_dir,
time_label=message)
# normalization instead of normalizing the forward solution.
# Estimate the cross-spectral density (CSD) matrix on the trial containing the
# signal.
csd_signal = csd_morlet(epochs['signal'], frequencies=[10])
# Compute the spatial filters for each vertex, using two approaches.
filters_approach1 = make_dics(
info, fwd, csd_signal, reg=0.05, pick_ori='max-power', normalize_fwd=True,
inversion='single', weight_norm=None)
filters_approach2 = make_dics(
info, fwd, csd_signal, reg=0.05, pick_ori='max-power', normalize_fwd=False,
inversion='matrix', weight_norm='unit-noise-gain')
# Compute the DICS power map by applying the spatial filters to the CSD matrix.
power_approach1, f = apply_dics_csd(csd_signal, filters_approach1)
power_approach2, f = apply_dics_csd(csd_signal, filters_approach2)
# Plot the DICS power maps for both approaches.
for approach, power in enumerate([power_approach1, power_approach2], 1):
brain = power.plot('sample', subjects_dir=subjects_dir, hemi='both',
figure=approach + 1, size=600)
# Indicate the true locations of the source activity on the plot.
brain.add_foci(source_vert1, coords_as_verts=True, hemi='lh')
brain.add_foci(source_vert2, coords_as_verts=True, hemi='rh')
# Rotate the view and add a title.
mlab.view(0, 0, 550, [0, 0, 0])
mlab.title('DICS power map, approach %d' % approach, height=0.9)
csd_baseline = csd_baseline.mean()
csd_ers = csd_ers.mean()
###############################################################################
# Computing DICS spatial filters using the CSD that was computed on the entire
# timecourse.
filters = make_dics(epochs.info,
fwd,
csd,
noise_csd=csd_baseline,
pick_ori='max-power')
###############################################################################
# Applying DICS spatial filters separately to the CSD computed using the
# baseline and the CSD computed during the ERS activity.
baseline_source_power, freqs = apply_dics_csd(csd_baseline, filters)
beta_source_power, freqs = apply_dics_csd(csd_ers, filters)
###############################################################################
# Visualizing source power during ERS activity relative to the baseline power.
stc = beta_source_power / baseline_source_power
message = 'DICS source power in the 12-30 Hz frequency band'
brain = stc.plot(hemi='both',
views='par',
subjects_dir=subjects_dir,
subject=subject,
time_label=message)
###############################################################################
# References
# ----------
weight_norm=None,
normalize_fwd=True,
real_filter=False)
del epo_exp, fwd_exp, csd_exp
filters_bas = make_dics(epo_bas.info,
fwd_base,
csd_bas,
pick_ori='max-power',
rank=None,
inversion='single',
weight_norm=None,
normalize_fwd=True,
real_filter=False)
del epo_bas, fwd_base, csd_bas
# apply the DICS beamformers to get source Estimates for (base) rest, tonbas & (exp) ton, neg, pos using common filters & save to file
stc_rest, freqs_rest = apply_dics_csd(csd_rest, filters_bas)
del csd_rest
stc_rest.save(fname=meg_dir + "nc_{}_stc_rest_1-90".format(meg))
stc_tonbas, freqs_tonbas = apply_dics_csd(csd_ton, filters_bas)
stc_tonbas.save(fname=meg_dir + "nc_{}_stc_tonbas_1-90".format(meg))
del filters_bas
stc_ton, freqs_ton = apply_dics_csd(csd_ton, filters_exp)
stc_ton.save(fname=meg_dir + "nc_{}_stc_ton_1-90".format(meg))
del csd_ton
stc_neg, freqs_neg = apply_dics_csd(csd_neg, filters_exp)
del csd_neg
stc_neg.save(fname=meg_dir + "nc_{}_stc_neg_1-90".format(meg))
stc_pos, freqs_pos = apply_dics_csd(csd_pos, filters_exp)
del csd_pos
stc_pos.save(fname=meg_dir + "nc_{}_stc_pos_1-90".format(meg))
# calculate the difference between conditions div. by baseline & save to file (for base and for exp)
def test_tf_dics():
"""Test 5D time-frequency beamforming based on DICS."""
fwd_free, fwd_surf, fwd_fixed, fwd_vol, label = _load_forward()
epochs, evoked, _, source_vertno = _simulate_data(fwd_fixed)
vertices = np.intersect1d(label.vertices, fwd_free['src'][0]['vertno'])
source_ind = vertices.tolist().index(source_vertno)
reg = 1 # Lots of regularization for our toy dataset
tmin = 0
tmax = 9
tstep = 4
win_lengths = [5, 5]
frequencies = [10, 20]
freq_bins = [(8, 12), (18, 22)]
# Compute DICS for two time windows and two frequencies
for mode in ['fourier', 'multitaper', 'cwt_morlet']:
stcs = tf_dics(epochs, fwd_surf, None, tmin, tmax, tstep, win_lengths,
mode=mode, freq_bins=freq_bins, frequencies=frequencies,
decim=10, reg=reg, label=label)
# Did we find the true source at 20 Hz?
assert np.argmax(stcs[1].data[:, 0]) == source_ind
assert np.argmax(stcs[1].data[:, 1]) == source_ind
# 20 Hz power should decrease over time
assert stcs[1].data[source_ind, 0] > stcs[1].data[source_ind, 1]
# 20 Hz power should be more than 10 Hz power at the true source
assert stcs[1].data[source_ind, 0] > stcs[0].data[source_ind, 0]
# Manually compute source power and compare with the last tf_dics result.
source_power = []
time_windows = [(0, 5), (4, 9)]
for time_window in time_windows:
csd = csd_morlet(epochs, frequencies=[frequencies[1]],
tmin=time_window[0], tmax=time_window[1], decim=10)
csd = csd.sum()
csd._data /= csd.n_fft
filters = make_dics(epochs.info, fwd_surf, csd, reg=reg, label=label)
stc_source_power, _ = apply_dics_csd(csd, filters)
source_power.append(stc_source_power.data)
# Comparing tf_dics results with dics_source_power results
assert_allclose(stcs[1].data, np.array(source_power).squeeze().T, atol=0)
# Test using noise csds. We're going to use identity matrices. That way,
# since we're using unit-noise-gain weight normalization, there should be
# no effect.
stcs = tf_dics(epochs, fwd_surf, None, tmin, tmax, tstep, win_lengths,
mode='cwt_morlet', frequencies=frequencies, decim=10,
reg=reg, label=label, normalize_fwd=False,
weight_norm='unit-noise-gain')
noise_csd = csd.copy()
inds = np.triu_indices(csd.n_channels)
# Using [:, :] syntax for in-place broadcasting
noise_csd._data[:, :] = 2 * np.eye(csd.n_channels)[inds][:, np.newaxis]
noise_csd.n_fft = 2 # Dividing by n_fft should yield an identity CSD
noise_csds = [noise_csd, noise_csd] # Two frequency bins
stcs_norm = tf_dics(epochs, fwd_surf, noise_csds, tmin, tmax, tstep,
win_lengths, mode='cwt_morlet',
frequencies=frequencies, decim=10, reg=reg,
label=label, normalize_fwd=False,
weight_norm='unit-noise-gain')
assert_allclose(stcs_norm[0].data, stcs[0].data, atol=0)
assert_allclose(stcs_norm[1].data, stcs[1].data, atol=0)
# Test invalid parameter combinations
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths, mode='fourier', freq_bins=None)
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths, mode='cwt_morlet', frequencies=None)
# Test if incorrect number of noise CSDs is detected
raises(ValueError, tf_dics, epochs, fwd_surf, [noise_csds[0]], tmin, tmax,
tstep, win_lengths, freq_bins=freq_bins)
# Test if freq_bins and win_lengths incompatibility is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths=[0, 1, 2], freq_bins=freq_bins)
# Test if time step exceeding window lengths is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep=0.15,
win_lengths=[0.2, 0.1], freq_bins=freq_bins)
# Test if incorrent number of n_ffts is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths, freq_bins=freq_bins, n_ffts=[1])
# Test if incorrect number of mt_bandwidths is detected
raises(ValueError, tf_dics, epochs, fwd_surf, None, tmin, tmax, tstep,
win_lengths=win_lengths, freq_bins=freq_bins, mode='multitaper',
mt_bandwidths=[20])
# Test if subtracting evoked responses yields NaN's, since we only have one
# epoch. Suppress division warnings.
with pytest.warns(RuntimeWarning, match='[invalid|empty]'):
stcs = tf_dics(epochs, fwd_surf, None, tmin, tmax, tstep, win_lengths,
mode='cwt_morlet', frequencies=frequencies,
subtract_evoked=True, reg=reg, label=label, decim=20)
assert np.all(np.isnan(stcs[0].data))
inversion='single',
weight_norm=None,
normalize_fwd=True,
real_filter=False)
filters_bas_gamma = make_dics(epo_bas.info,
fwd_base,
csd_bas_gamma,
pick_ori='max-power',
rank=None,
inversion='single',
weight_norm=None,
normalize_fwd=True,
real_filter=False)
# apply the DICS beamformers to get source Estimates for ton, rest using common filters & save to file
stc_ton_alpha, freqs_ton_alpha = apply_dics_csd(csd_ton_alpha,
filters_bas_alpha)
stc_ton_theta, freqs_ton_theta = apply_dics_csd(csd_ton_theta,
filters_bas_theta)
stc_ton_beta_low, freqs_ton_beta_low = apply_dics_csd(
csd_ton_beta_low, filters_bas_beta_low)
stc_ton_beta_high, freqs_ton_beta_high = apply_dics_csd(
csd_ton_beta_high, filters_bas_beta_high)
stc_ton_gamma, freqs_ton_gamma = apply_dics_csd(csd_ton_gamma,
filters_bas_gamma)
stc_ton_alpha.save(fname=meg_dir + "nc_{}_stc_tonbas_alpha".format(meg))
stc_ton_theta.save(fname=meg_dir + "nc_{}_stc_tonbas_theta".format(meg))
stc_ton_beta_low.save(fname=meg_dir +
"nc_{}_stc_tonbas_beta_low".format(meg))
stc_ton_beta_high.save(fname=meg_dir +
"nc_{}_stc_tonbas_beta_high".format(meg))
stc_ton_gamma.save(fname=meg_dir + "nc_{}_stc_tonbas_gamma".format(meg))