def test_compute_epochs_csd_on_artificial_data():
"""Test computing CSD on artificial data
"""
epochs, epochs_sin = _get_data()
sfreq = epochs_sin.info['sfreq']
# Computing signal power in the time domain
signal_power = sum_squared(epochs_sin._data)
signal_power_per_sample = signal_power / len(epochs_sin.times)
# Computing signal power in the frequency domain
data_csd_fourier = compute_epochs_csd(epochs_sin, mode='fourier')
data_csd_mt = compute_epochs_csd(epochs_sin, mode='multitaper')
fourier_power = np.abs(data_csd_fourier.data[0, 0]) * sfreq
mt_power = np.abs(data_csd_mt.data[0, 0]) * sfreq
assert_true(abs(fourier_power - signal_power) <= 0.5)
assert_true(abs(mt_power - signal_power) <= 1)
# Power per sample should not depend on time window length
for tmax in [0.2, 0.4, 0.6, 0.8]:
for add_n_fft in [30, 0, 30]:
t_mask = (epochs_sin.times >= 0) & (epochs_sin.times <= tmax)
n_samples = sum(t_mask)
n_fft = n_samples + add_n_fft
data_csd_fourier = compute_epochs_csd(epochs_sin,
mode='fourier',
tmin=None,
tmax=tmax,
fmin=0,
fmax=np.inf,
n_fft=n_fft)
fourier_power_per_sample = np.abs(data_csd_fourier.data[0, 0]) *\
sfreq / data_csd_fourier.n_fft
assert_true(
abs(signal_power_per_sample -
fourier_power_per_sample) < 0.003)
# Power per sample should not depend on number of tapers
for n_tapers in [1, 2, 3, 5]:
for add_n_fft in [30, 0, 30]:
mt_bandwidth = sfreq / float(n_samples) * (n_tapers + 1)
data_csd_mt = compute_epochs_csd(epochs_sin,
mode='multitaper',
tmin=None,
tmax=tmax,
fmin=0,
fmax=np.inf,
mt_bandwidth=mt_bandwidth,
n_fft=n_fft)
mt_power_per_sample = np.abs(data_csd_mt.data[0, 0]) *\
sfreq / data_csd_mt.n_fft
# The estimate of power gets worse for small time windows when
# more tapers are used
if n_tapers == 5 and tmax == 0.2:
delta = 0.05
else:
delta = 0.004
assert_true(
abs(signal_power_per_sample - mt_power_per_sample) < delta)
def test_compute_epochs_csd():
"""Test computing cross-spectral density from epochs
"""
epochs, epochs_sin = _get_data()
# Check that wrong parameters are recognized
assert_raises(ValueError, compute_epochs_csd, epochs, mode="notamode")
assert_raises(ValueError, compute_epochs_csd, epochs, fmin=20, fmax=10)
assert_raises(ValueError, compute_epochs_csd, epochs, fmin=20, fmax=20.1)
assert_raises(ValueError, compute_epochs_csd, epochs, tmin=0.15, tmax=0.1)
assert_raises(ValueError, compute_epochs_csd, epochs, tmin=0, tmax=10)
assert_raises(ValueError, compute_epochs_csd, epochs, tmin=10, tmax=11)
data_csd_mt = compute_epochs_csd(epochs, mode="multitaper", fmin=8, fmax=12, tmin=0.04, tmax=0.15)
data_csd_fourier = compute_epochs_csd(epochs, mode="fourier", fmin=8, fmax=12, tmin=0.04, tmax=0.15)
# Check shape of the CSD matrix
n_chan = len(data_csd_mt.ch_names)
assert_equal(data_csd_mt.data.shape, (n_chan, n_chan))
assert_equal(data_csd_fourier.data.shape, (n_chan, n_chan))
# Check if the CSD matrix is hermitian
assert_array_equal(np.tril(data_csd_mt.data).T.conj(), np.triu(data_csd_mt.data))
assert_array_equal(np.tril(data_csd_fourier.data).T.conj(), np.triu(data_csd_fourier.data))
# Computing induced power for comparison
epochs.crop(tmin=0.04, tmax=0.15)
power, _ = induced_power(epochs.get_data(), epochs.info["sfreq"], [10], n_cycles=0.6)
power = np.mean(power, 2)
# Maximum PSD should occur for specific channel
max_ch_power = power.argmax()
max_ch_mt = data_csd_mt.data.diagonal().argmax()
max_ch_fourier = data_csd_fourier.data.diagonal().argmax()
assert_equal(max_ch_mt, max_ch_power)
assert_equal(max_ch_fourier, max_ch_power)
# Maximum CSD should occur for specific channel
ch_csd_mt = [np.abs(data_csd_mt.data[max_ch_power][i]) if i != max_ch_power else 0 for i in range(n_chan)]
max_ch_csd_mt = np.argmax(ch_csd_mt)
ch_csd_fourier = [np.abs(data_csd_fourier.data[max_ch_power][i]) if i != max_ch_power else 0 for i in range(n_chan)]
max_ch_csd_fourier = np.argmax(ch_csd_fourier)
assert_equal(max_ch_csd_mt, max_ch_csd_fourier)
# Check a list of CSD matrices is returned for multiple frequencies within
# a given range when fsum=False
csd_fsum = compute_epochs_csd(epochs, mode="fourier", fmin=8, fmax=20, fsum=True)
csds = compute_epochs_csd(epochs, mode="fourier", fmin=8, fmax=20, fsum=False)
freqs = [csd.frequencies[0] for csd in csds]
csd_sum = np.zeros_like(csd_fsum.data)
for csd in csds:
csd_sum += csd.data
assert len(csds) == 2
assert len(csd_fsum.frequencies) == 2
assert_array_equal(csd_fsum.frequencies, freqs)
assert_array_equal(csd_fsum.data, csd_sum)
def test_compute_epochs_csd_on_artificial_data():
"""Test computing CSD on artificial data
"""
epochs, epochs_sin = _get_data()
sfreq = epochs_sin.info['sfreq']
# Computing signal power in the time domain
signal_power = sum_squared(epochs_sin._data)
signal_power_per_sample = signal_power / len(epochs_sin.times)
# Computing signal power in the frequency domain
data_csd_fourier = compute_epochs_csd(epochs_sin, mode='fourier')
data_csd_mt = compute_epochs_csd(epochs_sin, mode='multitaper')
fourier_power = np.abs(data_csd_fourier.data[0, 0]) * sfreq
mt_power = np.abs(data_csd_mt.data[0, 0]) * sfreq
assert_almost_equal(fourier_power, signal_power, delta=0.5)
assert_almost_equal(mt_power, signal_power, delta=1)
# Power per sample should not depend on time window length
for tmax in [0.2, 0.4, 0.6, 0.8]:
for add_n_fft in [30, 0, 30]:
t_mask = (epochs_sin.times >= 0) & (epochs_sin.times <= tmax)
n_samples = sum(t_mask)
n_fft = n_samples + add_n_fft
data_csd_fourier = compute_epochs_csd(epochs_sin, mode='fourier',
tmin=None, tmax=tmax, fmin=0,
fmax=np.inf, n_fft=n_fft)
fourier_power_per_sample = np.abs(data_csd_fourier.data[0, 0]) *\
sfreq / data_csd_fourier.n_fft
assert_almost_equal(signal_power_per_sample,
fourier_power_per_sample, delta=0.003)
# Power per sample should not depend on number of tapers
for n_tapers in [1, 2, 3, 5]:
for add_n_fft in [30, 0, 30]:
mt_bandwidth = sfreq / float(n_samples) * (n_tapers + 1)
data_csd_mt = compute_epochs_csd(epochs_sin, mode='multitaper',
tmin=None, tmax=tmax, fmin=0,
fmax=np.inf,
mt_bandwidth=mt_bandwidth,
n_fft=n_fft)
mt_power_per_sample = np.abs(data_csd_mt.data[0, 0]) *\
sfreq / data_csd_mt.n_fft
# The estimate of power gets worse for small time windows when
# more tapers are used
if n_tapers == 5 and tmax == 0.2:
delta = 0.05
else:
delta = 0.004
assert_almost_equal(signal_power_per_sample,
mt_power_per_sample, delta=delta)
def _get_data(tmin=-0.11, tmax=0.15, read_all_forward=True, compute_csds=True):
"""Read in data used in tests
"""
label = mne.read_label(fname_label)
events = mne.read_events(fname_event)[:10]
raw = mne.io.read_raw_fif(fname_raw, preload=False)
raw.add_proj([], remove_existing=True) # we'll subselect so remove proj
forward = mne.read_forward_solution(fname_fwd)
if read_all_forward:
forward_surf_ori = read_forward_solution_meg(fname_fwd, surf_ori=True)
forward_fixed = read_forward_solution_meg(fname_fwd, force_fixed=True,
surf_ori=True)
forward_vol = mne.read_forward_solution(fname_fwd_vol, surf_ori=True)
else:
forward_surf_ori = None
forward_fixed = None
forward_vol = None
event_id, tmin, tmax = 1, tmin, tmax
# Setup for reading the raw data
raw.info['bads'] = ['MEG 2443', 'EEG 053'] # 2 bads channels
# Set up pick list: MEG - bad channels
left_temporal_channels = mne.read_selection('Left-temporal')
picks = mne.pick_types(raw.info, meg=True, eeg=False,
stim=True, eog=True, exclude='bads',
selection=left_temporal_channels)
# Read epochs
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, eog=150e-6))
epochs.resample(200, npad=0, n_jobs=2)
evoked = epochs.average()
# Computing the data and noise cross-spectral density matrices
if compute_csds:
data_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=0.045,
tmax=None, fmin=8, fmax=12,
mt_bandwidth=72.72)
noise_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=None,
tmax=0.0, fmin=8, fmax=12,
mt_bandwidth=72.72)
else:
data_csd, noise_csd = None, None
return raw, epochs, evoked, data_csd, noise_csd, label, forward,\
forward_surf_ori, forward_fixed, forward_vol
def read_data():
"""Read in data used in tests
"""
label = mne.read_label(fname_label)
events = mne.read_events(fname_event)[:10]
raw = mne.fiff.Raw(fname_raw, preload=False)
forward = mne.read_forward_solution(fname_fwd)
forward_surf_ori = mne.read_forward_solution(fname_fwd, surf_ori=True)
forward_fixed = mne.read_forward_solution(fname_fwd, force_fixed=True,
surf_ori=True)
forward_vol = mne.read_forward_solution(fname_fwd_vol, surf_ori=True)
event_id, tmin, tmax = 1, -0.11, 0.15
# Setup for reading the raw data
raw.info['bads'] = ['MEG 2443', 'EEG 053'] # 2 bads channels
# Set up pick list: MEG - bad channels
left_temporal_channels = mne.read_selection('Left-temporal')
picks = mne.fiff.pick_types(raw.info, meg=True, eeg=False,
stim=True, eog=True, exclude='bads',
selection=left_temporal_channels)
# Read epochs
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, eog=150e-6))
epochs.resample(200, npad=0, n_jobs=2)
evoked = epochs.average()
# Computing the data and noise cross-spectral density matrices
data_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=0.04,
tmax=None, fmin=8, fmax=12)
noise_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=None,
tmax=0.0, fmin=8, fmax=12)
return raw, epochs, evoked, data_csd, noise_csd, label, forward,\
forward_surf_ori, forward_fixed, forward_vol
# Then set FFTs length for each frequency range.
# Should be a power of 2 to be faster.
n_ffts = [256, 128, 128, 128]
# Subtract evoked response prior to computation?
subtract_evoked = False
# Calculating noise cross-spectral density from empty room noise for each
# frequency bin and the corresponding time window length. To calculate noise
# from the baseline period in the data, change epochs_noise to epochs
noise_csds = []
for freq_bin, win_length, n_fft in zip(freq_bins, win_lengths, n_ffts):
noise_csd = compute_epochs_csd(epochs_noise,
mode='fourier',
fmin=freq_bin[0],
fmax=freq_bin[1],
fsum=True,
tmin=-win_length,
tmax=0,
n_fft=n_fft)
noise_csds.append(noise_csd)
# Computing DICS solutions for time-frequency windows in a label in source
# space for faster computation, use label=None for full solution
stcs = tf_dics(epochs,
forward,
noise_csds,
tmin,
tmax,
tstep,
win_lengths,
freq_bins=freq_bins,
def test_tf_dics():
"""Test TF beamforming based on DICS
"""
tmin, tmax, tstep = -0.2, 0.2, 0.1
raw, epochs, _, _, _, label, forward, _, _, _ =\
_get_data(tmin, tmax, read_all_forward=False, compute_csds=False)
freq_bins = [(4, 20), (30, 55)]
win_lengths = [0.2, 0.2]
reg = 0.001
noise_csds = []
for freq_bin, win_length in zip(freq_bins, win_lengths):
noise_csd = compute_epochs_csd(epochs,
mode='fourier',
fmin=freq_bin[0],
fmax=freq_bin[1],
fsum=True,
tmin=tmin,
tmax=tmin + win_length)
noise_csds.append(noise_csd)
stcs = tf_dics(epochs,
forward,
noise_csds,
tmin,
tmax,
tstep,
win_lengths,
freq_bins,
reg=reg,
label=label)
assert_true(len(stcs) == len(freq_bins))
assert_true(stcs[0].shape[1] == 4)
# Manually calculating source power in several time windows to compare
# results and test overlapping
source_power = []
time_windows = [(-0.1, 0.1), (0.0, 0.2)]
for time_window in time_windows:
data_csd = compute_epochs_csd(epochs,
mode='fourier',
fmin=freq_bins[0][0],
fmax=freq_bins[0][1],
fsum=True,
tmin=time_window[0],
tmax=time_window[1])
noise_csd = compute_epochs_csd(epochs,
mode='fourier',
fmin=freq_bins[0][0],
fmax=freq_bins[0][1],
fsum=True,
tmin=-0.2,
tmax=0.0)
data_csd.data /= data_csd.n_fft
noise_csd.data /= noise_csd.n_fft
stc_source_power = dics_source_power(epochs.info,
forward,
noise_csd,
data_csd,
reg=reg,
label=label)
source_power.append(stc_source_power.data)
# Averaging all time windows that overlap the time period 0 to 100 ms
source_power = np.mean(source_power, axis=0)
# Selecting the first frequency bin in tf_dics results
stc = stcs[0]
# Comparing tf_dics results with dics_source_power results
assert_array_almost_equal(stc.data[:, 2], source_power[:, 0])
# Test if using unsupported max-power orientation is detected
assert_raises(ValueError,
tf_dics,
epochs,
forward,
noise_csds,
tmin,
tmax,
tstep,
win_lengths,
freq_bins=freq_bins,
pick_ori='max-power')
# Test if incorrect number of noise CSDs is detected
assert_raises(ValueError,
tf_dics,
epochs,
forward, [noise_csds[0]],
tmin,
tmax,
tstep,
win_lengths,
freq_bins=freq_bins)
# Test if freq_bins and win_lengths incompatibility is detected
assert_raises(ValueError,
tf_dics,
epochs,
forward,
noise_csds,
tmin,
tmax,
tstep,
win_lengths=[0, 1, 2],
freq_bins=freq_bins)
# Test if time step exceeding window lengths is detected
assert_raises(ValueError,
tf_dics,
epochs,
forward,
noise_csds,
tmin,
tmax,
tstep=0.15,
win_lengths=[0.2, 0.1],
freq_bins=freq_bins)
# Test if incorrect number of mt_bandwidths is detected
assert_raises(ValueError,
tf_dics,
epochs,
forward,
noise_csds,
tmin,
tmax,
tstep,
win_lengths,
freq_bins,
mode='multitaper',
mt_bandwidths=[20])
# Pass only one epoch to test if subtracting evoked responses yields zeros
stcs = tf_dics(epochs[0],
forward,
noise_csds,
tmin,
tmax,
tstep,
win_lengths,
freq_bins,
subtract_evoked=True,
reg=reg,
label=label)
assert_array_almost_equal(stcs[0].data, np.zeros_like(stcs[0].data))
def DICS_inverse(fn_epo, event_id=1,event='LLst', ctmin=0.05, ctmax=0.25, fmin=4, fmax=8,
min_subject='fsaverage'):
"""
Inverse evokes into source space using DICS method.
----------
fn_epo : epochs of raw data.
event_id: event id related with epochs.
ctmin: the min time for computing CSD
ctmax: the max time for computing CSD
fmin: min value of the interest frequency band
fmax: max value of the interest frequency band
min_subject: the subject for the common brain space.
save_forward: Whether save the forward solution or not.
"""
from mne import Epochs, pick_types
from mne.io import Raw
from mne.event import make_fixed_length_events
fnlist = get_files_from_list(fn_epo)
# loop across all filenames
for fname in fnlist:
meg_path = os.path.split(fname)[0]
name = os.path.basename(fname)
stc_name = name[:name.rfind('-epo.fif')]
subject = name.split('_')[0]
subject_path = subjects_dir + '/%s' %subject
min_dir = subjects_dir + '/%s' %min_subject
fn_trans = meg_path + '/%s-trans.fif' % subject
fn_src = subject_path + '/bem/%s-ico-5-src.fif' % subject
fn_bem = subject_path + '/bem/%s-5120-5120-5120-bem-sol.fif' % subject
# Make sure the target path is exist
stc_path = min_dir + '/DICS_ROIs/%s' % subject
set_directory(stc_path)
# Read the MNI source space
epochs = mne.read_epochs(fname)
tmin = epochs.times.min()
tmax = epochs.times.max()
fn_empty = meg_path + '/%s_empty,nr-raw.fif' % subject
raw_noise = Raw(fn_empty, preload=True)
epochs.info['bads'] = raw_noise.info['bads']
picks_noise = pick_types(raw_noise.info, meg='mag', exclude='bads')
events_noise = make_fixed_length_events(raw_noise, event_id, duration=1.)
epochs_noise = Epochs(raw_noise, events_noise, event_id, tmin,
tmax, proj=True, picks=picks_noise,
baseline=None, preload=True, reject=None)
# Make sure the number of noise epochs is the same as data epochs
epochs_noise = epochs_noise[:len(epochs.events)]
evoked = epochs.average()
forward = mne.make_forward_solution(epochs.info, trans=fn_trans,
src=fn_src, bem=fn_bem,
fname=None, meg=True, eeg=False,
mindist=5.0, n_jobs=2,
overwrite=True)
forward = mne.convert_forward_solution(forward, surf_ori=True)
from mne.time_frequency import compute_epochs_csd
from mne.beamformer import dics
data_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=ctmin, tmax=ctmax,
fmin=fmin, fmax=fmax)
noise_csd = compute_epochs_csd(epochs_noise, mode='multitaper', tmin=ctmin, tmax=ctmax,
fmin=fmin, fmax=fmax)
stc = dics(evoked, forward, noise_csd, data_csd)
from mne import morph_data
stc_morph = morph_data(subject, min_subject, stc, grade=5, smooth=5)
stc_morph.save(stc_path + '/%s_%d_%d' % (event, fmin, fmax), ftype='stc')
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, surf_ori=True)
# Computing the data and noise cross-spectral density matrices
# The time-frequency window was chosen on the basis of spectrograms from
# example time_frequency/plot_time_frequency.py
data_csd = compute_epochs_csd(epochs,
mode='multitaper',
tmin=0.04,
tmax=0.15,
fmin=6,
fmax=10)
noise_csd = compute_epochs_csd(epochs,
mode='multitaper',
tmin=-0.11,
tmax=0.0,
fmin=6,
fmax=10)
evoked = epochs.average()
# Compute DICS spatial filter and estimate source time courses on evoked data
stc = dics(evoked, forward, noise_csd, data_csd)
plt.figure()
roi_pretty = roi.split('/')[-1].split('+')[0]
# right labels are normally in the second index
if avg_label[0] is not None:
label = avg_label[0].morph(subject_to=s)
else:
label = avg_label[1].morph(subject_to=s)
epochs_fname = home + '/data/meg/stop/parsed/%s_stop_parsed_matched_clean_BP1-100_DS300-epo.fif.gz' % s
epochs = mne.read_epochs(epochs_fname, proj=True)
fwd_fname = home + '/data/meg/stop/%s_task-5-fwd.fif' % s
fwd = mne.read_forward_solution(fwd_fname, surf_ori=True)
# calculate source power estimates for the whole brain
# quick hack in tmax ot make it the same length as btmax
data_csds = compute_epochs_csd(epochs[cond], mode='multitaper',
tmin=tmin, tmax=tmax + btmax,
fmin=band[0], fmax=band[1],
fsum=False)
noise_csds = compute_epochs_csd(epochs[cond], mode='multitaper',
tmin=btmin, tmax=btmax,
fmin=band[0], fmax=band[1],
fsum=False)
stc = dics_source_power(epochs.info, fwd, noise_csds, data_csds)
ts = mne.extract_label_time_course(stc, label, fwd['src'])
data.append(ts)
# export one CSV file
fname = out_dir + '%s_%s_%02dto%02d_tmin%.2f.csv' % (cond, roi_pretty, band[0],
band[1], tmin)
fid = open(fname, 'w')
fid.write('subj,power\n')
for j, d in enumerate(data):
def test_tf_dics():
"""Test TF beamforming based on DICS
"""
tmin, tmax, tstep = -0.2, 0.2, 0.1
raw, epochs, _, _, _, label, forward, _, _, _ =\
_get_data(tmin, tmax, read_all_forward=False, compute_csds=False)
freq_bins = [(4, 20), (30, 55)]
win_lengths = [0.2, 0.2]
reg = 0.001
noise_csds = []
for freq_bin, win_length in zip(freq_bins, win_lengths):
noise_csd = compute_epochs_csd(epochs, mode='fourier',
fmin=freq_bin[0], fmax=freq_bin[1],
fsum=True, tmin=tmin,
tmax=tmin + win_length)
noise_csds.append(noise_csd)
stcs = tf_dics(epochs, forward, noise_csds, tmin, tmax, tstep, win_lengths,
freq_bins, reg=reg, label=label)
assert_true(len(stcs) == len(freq_bins))
print(stcs[0].shape)
assert_true(stcs[0].shape[1] == 4)
# Manually calculating source power in several time windows to compare
# results and test overlapping
source_power = []
time_windows = [(-0.1, 0.1), (0.0, 0.2)]
for time_window in time_windows:
data_csd = compute_epochs_csd(epochs, mode='fourier',
fmin=freq_bins[0][0],
fmax=freq_bins[0][1], fsum=True,
tmin=time_window[0], tmax=time_window[1])
noise_csd = compute_epochs_csd(epochs, mode='fourier',
fmin=freq_bins[0][0],
fmax=freq_bins[0][1], fsum=True,
tmin=-0.2, tmax=0.0)
data_csd.data /= data_csd.n_fft
noise_csd.data /= noise_csd.n_fft
stc_source_power = dics_source_power(epochs.info, forward, noise_csd,
data_csd, reg=reg, label=label)
source_power.append(stc_source_power.data)
# Averaging all time windows that overlap the time period 0 to 100 ms
source_power = np.mean(source_power, axis=0)
# Selecting the first frequency bin in tf_dics results
stc = stcs[0]
# Comparing tf_dics results with dics_source_power results
assert_array_almost_equal(stc.data[:, 2], source_power[:, 0])
# Test if using unsupported max-power orientation is detected
assert_raises(ValueError, tf_dics, epochs, forward, noise_csds, tmin, tmax,
tstep, win_lengths, freq_bins=freq_bins,
pick_ori='max-power')
# Test if incorrect number of noise CSDs is detected
assert_raises(ValueError, tf_dics, epochs, forward, [noise_csds[0]], tmin,
tmax, tstep, win_lengths, freq_bins=freq_bins)
# Test if freq_bins and win_lengths incompatibility is detected
assert_raises(ValueError, tf_dics, epochs, forward, noise_csds, tmin, tmax,
tstep, win_lengths=[0, 1, 2], freq_bins=freq_bins)
# Test if time step exceeding window lengths is detected
assert_raises(ValueError, tf_dics, epochs, forward, noise_csds, tmin, tmax,
tstep=0.15, win_lengths=[0.2, 0.1], freq_bins=freq_bins)
# Test if incorrect number of mt_bandwidths is detected
assert_raises(ValueError, tf_dics, epochs, forward, noise_csds, tmin, tmax,
tstep, win_lengths, freq_bins, mode='multitaper',
mt_bandwidths=[20])
# Pass only one epoch to test if subtracting evoked responses yields zeros
stcs = tf_dics(epochs[0], forward, noise_csds, tmin, tmax, tstep,
win_lengths, freq_bins, subtract_evoked=True, reg=reg,
label=label)
assert_array_almost_equal(stcs[0].data, np.zeros_like(stcs[0].data))
def apply_inverse(fn_epo, event='LLst',ctmin=0.05, ctmax=0.25, nctmin=-0.2, nctmax=0,
fmin=4, fmax=8, min_subject='fsaverage', STCs=False):
"""
Inverse evokes into source space using DICS method.
----------
fn_epo : epochs of raw data.
event_id: event id related with epochs.
ctmin: the min time for computing CSD
ctmax: the max time for computing CSD
fmin: min value of the interest frequency band
fmax: max value of the interest frequency band
min_subject: the subject for the common brain space.
STCs: bool, make STCs of epochs.
"""
from mne import Epochs, pick_types
from mne.io import Raw
from mne.event import make_fixed_length_events
fnlist = get_files_from_list(fn_epo)
# loop across all filenames
for fname in fnlist:
subjects_dir = os.environ['SUBJECTS_DIR']
# extract the subject infromation from the file name
meg_path = os.path.split(fname)[0]
name = os.path.basename(fname)
stc_name = name[:name.rfind('-epo.fif')]
subject = name.split('_')[0]
subject_path = subjects_dir + '/%s' %subject
min_dir = subjects_dir + '/%s' %min_subject
fn_trans = meg_path + '/%s-trans.fif' % subject
fn_src = subject_path + '/bem/%s-ico-4-src.fif' % subject
fn_bem = subject_path + '/bem/%s-5120-5120-5120-bem-sol.fif' % subject
# Make sure the target path is exist
stc_path = min_dir + '/DICS_ROIs/%s' % subject
set_directory(stc_path)
# Read the MNI source space
epochs = mne.read_epochs(fname)
evoked = epochs.average()
forward = mne.make_forward_solution(epochs.info, trans=fn_trans,
src=fn_src, bem=fn_bem,
fname=None, meg=True, eeg=False,
mindist=5.0, n_jobs=2,
overwrite=True)
forward = mne.convert_forward_solution(forward, surf_ori=True)
from mne.time_frequency import compute_epochs_csd
from mne.beamformer import dics
data_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=ctmin, tmax=ctmax,
fmin=fmin, fmax=fmax)
noise_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=nctmin, tmax=nctmax,
fmin=fmin, fmax=fmax)
stc = dics(evoked, forward, noise_csd, data_csd)
from mne import morph_data
stc_morph = morph_data(subject, min_subject, stc, grade=4, smooth=4)
stc_morph.save(stc_path + '/%s_%d_%d' % (stc_name, fmin, fmax), ftype='stc')
if STCs == True:
stcs_path = stc_path + '/STCs-%s/' %event
reset_directory(stcs_path)
stcs = dics(epochs, forward, noise_csd, data_csd)
s = 0
while s < len(stcs):
stc_morph = mne.morph_data(subject, min_subject, stcs[s], grade=4, smooth=4)
stc_morph.save(stcs_path + '/trial_%s'
% (str(s)), ftype='stc')
s = s + 1
if avg_label[0] is not None:
label = avg_label[0].morph(subject_to=s)
else:
label = avg_label[1].morph(subject_to=s)
epochs_fname = home + '/data/meg/stop/parsed/%s_stop_parsed_matched_clean_BP1-100_DS300-epo.fif.gz' % s
epochs = mne.read_epochs(epochs_fname, proj=True)
fwd_fname = home + '/data/meg/stop/%s_task-5-fwd.fif' % s
fwd = mne.read_forward_solution(fwd_fname, surf_ori=True)
# calculate source power estimates for the whole brain
# quick hack in tmax ot make it the same length as btmax
data_csds = compute_epochs_csd(epochs[cond],
mode='multitaper',
tmin=tmin,
tmax=tmax + btmax,
fmin=band[0],
fmax=band[1],
fsum=False)
noise_csds = compute_epochs_csd(epochs[cond],
mode='multitaper',
tmin=btmin,
tmax=btmax,
fmin=band[0],
fmax=band[1],
fsum=False)
stc = dics_source_power(epochs.info, fwd, noise_csds, data_csds)
ts = mne.extract_label_time_course(stc, label, fwd['src'])
data.append(ts)
# export one CSV file
# Setting time windows, please note tmin stretches over the baseline, which is
# selected to be as long as the longest time window. This enables a smooth and
# accurate localization of activity in time
tmin = -0.3 # s
tmax = 0.5 # s
tstep = 0.05 # s
# Subtract evoked response prior to computation?
subtract_evoked = False
# Calculating noise cross-spectral density from empty room noise for each
# frequency bin and the corresponding time window length. To calculate noise
# from the baseline period in the data, change epochs_noise to epochs
noise_csds = []
for freq_bin, win_length, n_fft in zip(freq_bins, win_lengths, n_ffts):
noise_csd = compute_epochs_csd(epochs_noise, mode='fourier',
fmin=freq_bin[0], fmax=freq_bin[1],
fsum=True, tmin=tmin,
tmax=tmin + win_length, n_fft=n_fft)
noise_csds.append(noise_csd)
# Computing DICS solutions for time-frequency windows in a label in source
# space for faster computation, use label=None for full solution
stcs = tf_dics(epochs, forward, noise_csds, tmin, tmax, tstep, win_lengths,
freq_bins=freq_bins, subtract_evoked=subtract_evoked,
n_ffts=n_ffts, reg=0.001, label=label)
# Plotting source spectrogram for source with maximum activity
plot_source_spectrogram(stcs, freq_bins, source_index=None, colorbar=True)
stc = lcmv(evoked_ds[c],
forward,
cov_base,
data_cov,
reg=0.01,
pick_ori='max-power')
stc = mne.morph_data_precomputed(subj, 'fsaverage', stc, vertices_to,
morph_mat)
fname = out_dir + '%s_%s_LCMV_base_clean' % (subj, conds[c])
stc.save(fname)
# finally, compute DICS per band
for band in bands:
data_csd = compute_epochs_csd(epochs[conds[c]],
mode='multitaper',
tmin=tmin,
tmax=tmax + btmax,
fmin=band[0],
fmax=band[1])
noise_csd = compute_epochs_csd(epochs[conds[c]],
mode='multitaper',
tmin=btmin,
tmax=btmax,
fmin=band[0],
fmax=band[1])
stc = dics(evoked[c], forward, noise_csd, data_csd)
stc = mne.morph_data_precomputed(subj, 'fsaverage', stc, vertices_to,
morph_mat)
stc.resample(20)
fname = out_dir + '%s_%s_DICSevoked_%dto%d_clean' % (subj, conds[c],
band[0], band[1])
stc.save(fname)
def estimate_beamformer(epochs,
fname_forward_sol,
noise_cov_mat=None,
method="DICS",
show=True):
""""Estimates source localization for the given data set using beamformer."""
# read forward operator
forward_sol = mne.read_forward_solution(fname_forward_sol, surf_ori=True)
if method == "DICS":
print ">>>> performing source localization using DICS beamformer..."
# Computing the data and noise cross-spectral density matrices
data_csds = compute_epochs_csd(epochs,
mode='fourier',
tmin=0.04,
tmax=0.15,
fmin=5,
fmax=20)
noise_csds = compute_epochs_csd(epochs,
mode='fourier',
tmin=-0.11,
tmax=-0.0,
fmin=5,
fmax=20)
pdb.set_trace()
# Compute DICS spatial filter and estimate source power
src_loc = beam.dics(epochs.average(), forward_sol, noise_csds,
data_csds)
# for showing results
fmin = 0.5
fmid = 3.0
fmax = 5.0
else:
print ">>>> performing source localization using LCMV beamformer..."
if noise_cov_mat is None:
print "To use LCMV beamformer the noise-covariance matrix keyword must be set."
sys.exit()
evoked = epochs.average()
noise_cov_mat = mne.cov.regularize(noise_cov_mat,
evoked.info,
mag=0.05,
proj=True)
data_cov = mne.compute_covariance(epochs, tmin=0.04, tmax=0.15)
src_loc = beam.lcmv(evoked,
forward_sol,
noise_cov_mat,
data_cov,
reg=0.01,
pick_ori=None)
# for showing results
fmin = 0.01
fmid = 0.5
fmax = 1.0
# show results if desired
if show is not None:
subjects_dir = os.environ.get('SUBJECTS_DIR')
brain = src_loc.plot(surface='inflated',
hemi='both',
subjects_dir=subjects_dir,
config_opts={'cortex': 'bone'},
time_viewer=True,
fmin=fmin,
fmid=fmid,
fmax=fmax)
# 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, surf_ori=True)
# Computing the data and noise cross-spectral density matrices
# The time-frequency window was chosen on the basis of spectrograms from
# example time_frequency/plot_time_frequency.py
data_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=0.04, tmax=0.15,
fmin=6, fmax=10)
noise_csd = compute_epochs_csd(epochs, mode='multitaper', tmin=-0.11, tmax=0.0,
fmin=6, fmax=10)
evoked = epochs.average()
# Compute DICS spatial filter and estimate source time courses on evoked data
stc = dics(evoked, forward, noise_csd, data_csd)
plt.figure()
ts_show = -30 # show the 40 largest responses
plt.plot(1e3 * stc.times,
stc.data[np.argsort(stc.data.max(axis=1))[ts_show:]].T)
plt.xlabel('Time (ms)')
plt.ylabel('DICS value')
plt.title('DICS time course of the 30 largest sources.')
def estimate_beamformer(epochs,
fname_forward_sol,
noise_cov_mat=None,
method="DICS",
show=True):
""""Estimates source localization for the given data set using beamformer."""
# read forward operator
forward_sol = mne.read_forward_solution(fname_forward_sol, surf_ori=True)
if method == "DICS":
print ">>>> performing source localization using DICS beamformer..."
# Computing the data and noise cross-spectral density matrices
data_csds = compute_epochs_csd(epochs,
mode='fourier',
tmin=0.04,
tmax=0.15,
fmin=5,
fmax=20)
noise_csds = compute_epochs_csd(epochs,
mode='fourier',
tmin=-0.11,
tmax=-0.0,
fmin=5,
fmax=20)
pdb.set_trace()
# Compute DICS spatial filter and estimate source power
src_loc = beam.dics(epochs.average(),
forward_sol,
noise_csds,
data_csds)
# for showing results
fmin = 0.5; fmid = 3.0; fmax = 5.0
else:
print ">>>> performing source localization using LCMV beamformer..."
if noise_cov_mat is None:
print "To use LCMV beamformer the noise-covariance matrix keyword must be set."
sys.exit()
evoked = epochs.average()
noise_cov_mat = mne.cov.regularize(noise_cov_mat,
evoked.info,
mag=0.05,
proj=True)
data_cov = mne.compute_covariance(epochs,
tmin=0.04,
tmax=0.15)
src_loc = beam.lcmv(evoked,
forward_sol,
noise_cov_mat,
data_cov,
reg=0.01,
pick_ori=None)
# for showing results
fmin = 0.01; fmid = 0.5; fmax = 1.0
# show results if desired
if show is not None:
subjects_dir = os.environ.get('SUBJECTS_DIR')
brain = src_loc.plot(surface='inflated',
hemi='both',
subjects_dir=subjects_dir,
config_opts={'cortex':'bone'},
time_viewer=True,
fmin=fmin,
fmid=fmid,
fmax=fmax)
pick_ori='max-power')
stc = mne.morph_data_precomputed(subj, 'fsaverage', stc,
vertices_to, morph_mat)
fname = out_dir + '%s_%s_LCMV_blank_clean' % (subj, conds[c])
stc.save(fname)
stc = lcmv(evoked_ds[c], forward, cov_base, data_cov, reg=0.01,
pick_ori='max-power')
stc = mne.morph_data_precomputed(subj, 'fsaverage', stc,
vertices_to, morph_mat)
fname = out_dir + '%s_%s_LCMV_base_clean' % (subj, conds[c])
stc.save(fname)
# finally, compute DICS per band
for band in bands:
data_csd = compute_epochs_csd(epochs[conds[c]], mode='multitaper',
tmin=tmin, tmax=tmax + btmax,
fmin=band[0], fmax=band[1])
noise_csd = compute_epochs_csd(epochs[conds[c]], mode='multitaper',
tmin=btmin, tmax=btmax,
fmin=band[0], fmax=band[1])
stc = dics(evoked[c], forward, noise_csd, data_csd)
stc = mne.morph_data_precomputed(subj, 'fsaverage', stc,
vertices_to, morph_mat)
stc.resample(20)
fname = out_dir + '%s_%s_DICSevoked_%dto%d_clean' % (subj, conds[c],
band[0], band[1])
stc.save(fname)
stc = dics_source_power(epochs.info, forward, noise_csd, data_csd)
stc = mne.morph_data_precomputed(subj, 'fsaverage', stc,
vertices_to, morph_mat)
fname = out_dir + '%s_%s_DICSepochs_%dto%d_clean' % (subj, conds[c],
preload=True,
reject=dict(grad=4000e-13, mag=4e-12))
evoked = epochs.average()
# Read forward operator
forward = mne.read_forward_solution(fname_fwd, surf_ori=True)
# Computing the data and noise cross-spectral density matrices
# The time-frequency window was chosen on the basis of spectrograms from
# example time_frequency/plot_time_frequency.py
# As fsum is False compute_epochs_csd returns a list of CrossSpectralDensity
# instances than can then be passed to dics_source_power
data_csds = compute_epochs_csd(epochs,
mode='multitaper',
tmin=0.04,
tmax=0.15,
fmin=30,
fmax=50,
fsum=False)
noise_csds = compute_epochs_csd(epochs,
mode='multitaper',
tmin=-0.11,
tmax=-0.001,
fmin=30,
fmax=50,
fsum=False)
# Compute DICS spatial filter and estimate source power
stc = dics_source_power(epochs.info, forward, noise_csds, data_csds)
# Plot source power separately for each frequency of interest
def test_compute_epochs_csd():
"""Test computing cross-spectral density from epochs
"""
epochs, epochs_sin = _get_data()
# Check that wrong parameters are recognized
assert_raises(ValueError, compute_epochs_csd, epochs, mode='notamode')
assert_raises(ValueError, compute_epochs_csd, epochs, fmin=20, fmax=10)
assert_raises(ValueError, compute_epochs_csd, epochs, fmin=20, fmax=20.1)
assert_raises(ValueError, compute_epochs_csd, epochs, tmin=0.15, tmax=0.1)
assert_raises(ValueError, compute_epochs_csd, epochs, tmin=0, tmax=10)
assert_raises(ValueError, compute_epochs_csd, epochs, tmin=10, tmax=11)
data_csd_mt = compute_epochs_csd(epochs, mode='multitaper', fmin=8,
fmax=12, tmin=0.04, tmax=0.15)
data_csd_fourier = compute_epochs_csd(epochs, mode='fourier', fmin=8,
fmax=12, tmin=0.04, tmax=0.15)
# Check shape of the CSD matrix
n_chan = len(data_csd_mt.ch_names)
assert_equal(data_csd_mt.data.shape, (n_chan, n_chan))
assert_equal(data_csd_fourier.data.shape, (n_chan, n_chan))
# Check if the CSD matrix is hermitian
assert_array_equal(np.tril(data_csd_mt.data).T.conj(),
np.triu(data_csd_mt.data))
assert_array_equal(np.tril(data_csd_fourier.data).T.conj(),
np.triu(data_csd_fourier.data))
# Computing induced power for comparison
epochs.crop(tmin=0.04, tmax=0.15)
power, _ = induced_power(epochs.get_data(), epochs.info['sfreq'], [10],
n_cycles=0.6)
power = np.mean(power, 2)
# Maximum PSD should occur for specific channel
max_ch_power = power.argmax()
max_ch_mt = data_csd_mt.data.diagonal().argmax()
max_ch_fourier = data_csd_fourier.data.diagonal().argmax()
assert_equal(max_ch_mt, max_ch_power)
assert_equal(max_ch_fourier, max_ch_power)
# Maximum CSD should occur for specific channel
ch_csd_mt = [np.abs(data_csd_mt.data[max_ch_power][i])
if i != max_ch_power else 0 for i in range(n_chan)]
max_ch_csd_mt = np.argmax(ch_csd_mt)
ch_csd_fourier = [np.abs(data_csd_fourier.data[max_ch_power][i])
if i != max_ch_power else 0 for i in range(n_chan)]
max_ch_csd_fourier = np.argmax(ch_csd_fourier)
assert_equal(max_ch_csd_mt, max_ch_csd_fourier)
# Check a list of CSD matrices is returned for multiple frequencies within
# a given range when fsum=False
csd_fsum = compute_epochs_csd(epochs, mode='fourier', fmin=8, fmax=20,
fsum=True)
csds = compute_epochs_csd(epochs, mode='fourier', fmin=8, fmax=20,
fsum=False)
freqs = [csd.frequencies[0] for csd in csds]
csd_sum = np.zeros_like(csd_fsum.data)
for csd in csds:
csd_sum += csd.data
assert(len(csds) == 2)
assert(len(csd_fsum.frequencies) == 2)
assert_array_equal(csd_fsum.frequencies, freqs)
assert_array_equal(csd_fsum.data, csd_sum)
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, surf_ori=True)
# Computing the data and noise cross-spectral density matrices
# The time-frequency window was chosen on the basis of spectrograms from
# example time_frequency/plot_time_frequency.py
# As fsum is False compute_epochs_csd returns a list of CrossSpectralDensity
# instances than can then be passed to dics_source_power
data_csds = compute_epochs_csd(epochs, mode='multitaper', tmin=0.04, tmax=0.15,
fmin=15, fmax=30, fsum=False)
noise_csds = compute_epochs_csd(epochs, mode='multitaper', tmin=-0.11,
tmax=-0.001, fmin=15, fmax=30, fsum=False)
# Compute DICS spatial filter and estimate source power
stc = dics_source_power(epochs.info, forward, noise_csds, data_csds)
clim = dict(kind='value', lims=[1.6, 1.9, 2.2])
for i, csd in enumerate(data_csds):
message = 'DICS source power at %0.1f Hz' % csd.frequencies[0]
brain = stc.plot(surface='inflated', hemi='rh', subjects_dir=subjects_dir,
time_label=message, figure=i, clim=clim, transparent=True)
brain.set_data_time_index(i)
brain.show_view('lateral')
# Uncomment line below to save images
# brain.save_image('DICS_source_power_freq_%d.png' % csd.frequencies[0])