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# Author: Alexandre Gramfort <alexandre.gramfort@telecom-paristech.fr>
#
# License: BSD (3-clause)
import os.path as op
from nose.tools import assert_true
from numpy.testing import assert_array_almost_equal
from nose.tools import assert_raises
import numpy as np
from scipy import linalg
import warnings
from mne.cov import regularize, whiten_evoked
from mne import (read_cov, write_cov, Epochs, merge_events,
find_events, compute_raw_data_covariance,
compute_covariance, read_evokeds)
from mne import pick_channels_cov, pick_channels, pick_types
from mne.io import Raw
from mne.utils import _TempDir
warnings.simplefilter('always') # enable b/c these tests throw warnings
base_dir = op.join(op.dirname(__file__), '..', 'io', 'tests', 'data')
cov_fname = op.join(base_dir, 'test-cov.fif')
cov_gz_fname = op.join(base_dir, 'test-cov.fif.gz')
cov_km_fname = op.join(base_dir, 'test-km-cov.fif')
raw_fname = op.join(base_dir, 'test_raw.fif')
ave_fname = op.join(base_dir, 'test-ave.fif')
erm_cov_fname = op.join(base_dir, 'test_erm-cov.fif')
tempdir = _TempDir()
def test_io_cov():
"""Test IO for noise covariance matrices
"""
cov = read_cov(cov_fname)
cov.save(op.join(tempdir, 'test-cov.fif'))
cov2 = read_cov(op.join(tempdir, 'test-cov.fif'))
assert_array_almost_equal(cov.data, cov2.data)
cov2 = read_cov(cov_gz_fname)
assert_array_almost_equal(cov.data, cov2.data)
cov2.save(op.join(tempdir, 'test-cov.fif.gz'))
cov2 = read_cov(op.join(tempdir, 'test-cov.fif.gz'))
assert_array_almost_equal(cov.data, cov2.data)
cov['bads'] = ['EEG 039']
cov_sel = pick_channels_cov(cov, exclude=cov['bads'])
assert_true(cov_sel['dim'] == (len(cov['data']) - len(cov['bads'])))
assert_true(cov_sel['data'].shape == (cov_sel['dim'], cov_sel['dim']))
cov_sel.save(op.join(tempdir, 'test-cov.fif'))
cov2 = read_cov(cov_gz_fname)
assert_array_almost_equal(cov.data, cov2.data)
cov2.save(op.join(tempdir, 'test-cov.fif.gz'))
cov2 = read_cov(op.join(tempdir, 'test-cov.fif.gz'))
assert_array_almost_equal(cov.data, cov2.data)
# test warnings on bad filenames
with warnings.catch_warnings(record=True) as w:
warnings.simplefilter('always')
cov_badname = op.join(tempdir, 'test-bad-name.fif.gz')
write_cov(cov_badname, cov)
read_cov(cov_badname)
assert_true(len(w) == 2)
def test_cov_estimation_on_raw_segment():
"""Test estimation from raw on continuous recordings (typically empty room)
"""
raw = Raw(raw_fname, preload=False)
cov = compute_raw_data_covariance(raw)
cov_mne = read_cov(erm_cov_fname)
assert_true(cov_mne.ch_names == cov.ch_names)
assert_true(linalg.norm(cov.data - cov_mne.data, ord='fro')
/ linalg.norm(cov.data, ord='fro') < 1e-4)
# test IO when computation done in Python
cov.save(op.join(tempdir, 'test-cov.fif')) # test saving
cov_read = read_cov(op.join(tempdir, 'test-cov.fif'))
assert_true(cov_read.ch_names == cov.ch_names)
assert_true(cov_read.nfree == cov.nfree)
assert_array_almost_equal(cov.data, cov_read.data)
# test with a subset of channels
picks = pick_channels(raw.ch_names, include=raw.ch_names[:5])
cov = compute_raw_data_covariance(raw, picks=picks)
assert_true(cov_mne.ch_names[:5] == cov.ch_names)
assert_true(linalg.norm(cov.data - cov_mne.data[picks][:, picks],
ord='fro') / linalg.norm(cov.data, ord='fro') < 1e-4)
# make sure we get a warning with too short a segment
raw_2 = raw.crop(0, 1)
with warnings.catch_warnings(record=True) as w:
warnings.simplefilter('always')
cov = compute_raw_data_covariance(raw_2)
assert_true(len(w) == 1)
def test_cov_estimation_with_triggers():
"""Test estimation from raw with triggers
"""
raw = Raw(raw_fname, preload=False)
events = find_events(raw, stim_channel='STI 014')
event_ids = [1, 2, 3, 4]
reject = dict(grad=10000e-13, mag=4e-12, eeg=80e-6, eog=150e-6)
# cov with merged events and keep_sample_mean=True
events_merged = merge_events(events, event_ids, 1234)
epochs = Epochs(raw, events_merged, 1234, tmin=-0.2, tmax=0,
baseline=(-0.2, -0.1), proj=True,
reject=reject, preload=True)
cov = compute_covariance(epochs, keep_sample_mean=True)
cov_mne = read_cov(cov_km_fname)
assert_true(cov_mne.ch_names == cov.ch_names)
assert_true((linalg.norm(cov.data - cov_mne.data, ord='fro')
/ linalg.norm(cov.data, ord='fro')) < 0.005)
# Test with tmin and tmax (different but not too much)
cov_tmin_tmax = compute_covariance(epochs, tmin=-0.19, tmax=-0.01)
assert_true(np.all(cov.data != cov_tmin_tmax.data))
assert_true((linalg.norm(cov.data - cov_tmin_tmax.data, ord='fro')
/ linalg.norm(cov_tmin_tmax.data, ord='fro')) < 0.05)
# cov using a list of epochs and keep_sample_mean=True
epochs = [Epochs(raw, events, ev_id, tmin=-0.2, tmax=0,
baseline=(-0.2, -0.1), proj=True, reject=reject)
for ev_id in event_ids]
cov2 = compute_covariance(epochs, keep_sample_mean=True)
assert_array_almost_equal(cov.data, cov2.data)
assert_true(cov.ch_names == cov2.ch_names)
# cov with keep_sample_mean=False using a list of epochs
cov = compute_covariance(epochs, keep_sample_mean=False)
cov_mne = read_cov(cov_fname)
assert_true(cov_mne.ch_names == cov.ch_names)
assert_true((linalg.norm(cov.data - cov_mne.data, ord='fro')
/ linalg.norm(cov.data, ord='fro')) < 0.005)
# test IO when computation done in Python
cov.save(op.join(tempdir, 'test-cov.fif')) # test saving
cov_read = read_cov(op.join(tempdir, 'test-cov.fif'))
assert_true(cov_read.ch_names == cov.ch_names)
assert_true(cov_read.nfree == cov.nfree)
assert_true((linalg.norm(cov.data - cov_read.data, ord='fro')
/ linalg.norm(cov.data, ord='fro')) < 1e-5)
# cov with list of epochs with different projectors
epochs = [Epochs(raw, events[:4], event_ids[0], tmin=-0.2, tmax=0,
baseline=(-0.2, -0.1), proj=True, reject=reject),
Epochs(raw, events[:4], event_ids[0], tmin=-0.2, tmax=0,
baseline=(-0.2, -0.1), proj=False, reject=reject)]
# these should fail
assert_raises(ValueError, compute_covariance, epochs)
assert_raises(ValueError, compute_covariance, epochs, projs=None)
# these should work, but won't be equal to above
with warnings.catch_warnings(record=True) as w: # too few samples warning
warnings.simplefilter('always')
cov = compute_covariance(epochs, projs=epochs[0].info['projs'])
cov = compute_covariance(epochs, projs=[])
assert_true(len(w) == 2)
# test new dict support
epochs = Epochs(raw, events, dict(a=1, b=2, c=3, d=4), tmin=-0.2, tmax=0,
baseline=(-0.2, -0.1), proj=True, reject=reject)
compute_covariance(epochs)
def test_arithmetic_cov():
"""Test arithmetic with noise covariance matrices
"""
cov = read_cov(cov_fname)
cov_sum = cov + cov
assert_array_almost_equal(2 * cov.nfree, cov_sum.nfree)
assert_array_almost_equal(2 * cov.data, cov_sum.data)
assert_true(cov.ch_names == cov_sum.ch_names)
cov += cov
assert_array_almost_equal(cov_sum.nfree, cov.nfree)
assert_array_almost_equal(cov_sum.data, cov.data)
assert_true(cov_sum.ch_names == cov.ch_names)
def test_regularize_cov():
"""Test cov regularization
"""
raw = Raw(raw_fname, preload=False)
raw.info['bads'].append(raw.ch_names[0]) # test with bad channels
noise_cov = read_cov(cov_fname)
# Regularize noise cov
reg_noise_cov = regularize(noise_cov, raw.info,
mag=0.1, grad=0.1, eeg=0.1, proj=True,
exclude='bads')
assert_true(noise_cov['dim'] == reg_noise_cov['dim'])
assert_true(noise_cov['data'].shape == reg_noise_cov['data'].shape)
assert_true(np.mean(noise_cov['data'] < reg_noise_cov['data']) < 0.08)
def test_evoked_whiten():
"""Test whitening of evoked data"""
evoked = read_evokeds(ave_fname, condition=0, baseline=(None, 0),
proj=True)
cov = read_cov(cov_fname)
###########################################################################
# Show result
picks = pick_types(evoked.info, meg=True, eeg=True, ref_meg=False,
exclude='bads')
noise_cov = regularize(cov, evoked.info, grad=0.1, mag=0.1, eeg=0.1,
exclude='bads')
evoked_white = whiten_evoked(evoked, noise_cov, picks, diag=True)
whiten_baseline_data = evoked_white.data[picks][:, evoked.times < 0]
mean_baseline = np.mean(np.abs(whiten_baseline_data), axis=1)
assert_true(np.all(mean_baseline < 1.))
assert_true(np.all(mean_baseline > 0.2))
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