def test_select_epochs(self):
"""Selecting Epochs."""
# normal case
dat = select_epochs(self.dat, [0])
self.assertEqual(dat.data.shape[0], 1)
np.testing.assert_array_equal(dat.data, self.dat.data[[0]])
np.testing.assert_array_equal(dat.axes[0], self.dat.axes[0][0])
# normal every second
dat = select_epochs(self.dat, [0, 2])
self.assertEqual(dat.data.shape[0], 2)
np.testing.assert_array_equal(dat.data, self.dat.data[::2])
np.testing.assert_array_equal(dat.axes[0], self.dat.axes[0][::2])
# the full epo
dat = select_epochs(self.dat, list(range(self.dat.data.shape[0])))
np.testing.assert_array_equal(dat.data, self.dat.data)
np.testing.assert_array_equal(dat.axes[0], self.dat.axes[0])
# remove one
dat = select_epochs(self.dat, [0], invert=True)
self.assertEqual(dat.data.shape[0], 3)
np.testing.assert_array_equal(dat.data, self.dat.data[1:])
np.testing.assert_array_equal(dat.axes[0], self.dat.axes[0][1:])
# remove every second
dat = select_epochs(self.dat, [0, 2], invert=True)
self.assertEqual(dat.data.shape[0], 2)
np.testing.assert_array_equal(dat.data, self.dat.data[1::2])
np.testing.assert_array_equal(dat.axes[0], self.dat.axes[0][1::2])
def run_fold(self, epo, bp_nr, fold_nr):
self.print_fold_nr(fold_nr)
train_test = self.folds[fold_nr]
train_ind = train_test['train']
test_ind = train_test['test']
epo_train = select_epochs(epo, train_ind)
epo_test = select_epochs(epo, test_ind)
if self.standardize_epo:
epo_train, epo_test = online_standardize_epo(epo_train, epo_test)
# TODELAY: also integrate into init and store results
self.train_labels_full_fold[fold_nr] = epo_train.axes[0]
self.test_labels_full_fold[fold_nr] = epo_test.axes[0]
for pair_nr in xrange(len(self.class_pairs)):
self.run_pair(epo_train, epo_test, bp_nr, fold_nr, pair_nr)
def run_fold(self, epo, bp_nr, fold_nr):
self.print_fold_nr(fold_nr)
train_test = self.folds[fold_nr]
train_ind = train_test["train"]
test_ind = train_test["test"]
epo_train = select_epochs(epo, train_ind)
epo_test = select_epochs(epo, test_ind)
if self.standardize_epo:
epo_train, epo_test = online_standardize_epo(epo_train, epo_test)
# TODELAY: also integrate into init and store results
self.train_labels_full_fold[fold_nr] = epo_train.axes[0]
self.test_labels_full_fold[fold_nr] = epo_test.axes[0]
for pair_nr in xrange(len(self.class_pairs)):
self.run_pair(epo_train, epo_test, bp_nr, fold_nr, pair_nr)
def preproc_and_load_clean_trials(self):
log.info("Preprocessing set...")
self.signal_processor.preprocess_continuous_signal()
self.signal_processor.segment_into_trials()
if len(self.rejected_trials) > 0:
self.signal_processor.epo = select_epochs(
self.signal_processor.epo, self.rejected_trials, invert=True)
# select epochs does not update marker structure...
clean_markers = [m for i,m in enumerate(self.signal_processor.epo.markers) \
if i not in self.rejected_trials]
self.signal_processor.epo.markers = clean_markers
self.signal_processor.remove_continuous_signal()
self.signal_processor.preprocess_trials()
log.info("Done.")
def fill_filterbank_data(self, full_epo_data):
for filterband_i in xrange(len(self.filterbands)):
low_freq, high_freq= self.filterbands[filterband_i]
log.info("Filterband {:d} of {:d}, from {:5.2f} to {:5.2f}".format(
filterband_i + 1, len(self.filterbands), low_freq, high_freq))
bandpassed_cnt = bandpass_cnt(self.signal_processor.cnt,
low_freq, high_freq, filt_order=3)
epo = segment_dat_fast(bandpassed_cnt,
marker_def={'1 - Right Hand': [1], '2 - Left Hand': [2],
'3 - Rest': [3], '4 - Feet': [4]},
ival=self.signal_processor.segment_ival)
epo.data = np.float32(epo.data)
epo = select_epochs(epo, self.rejected_trials, invert=True)
full_epo_data[:,:,:,filterband_i] = epo.data
del epo.data
del bandpassed_cnt
self.filterband_axes = epo.axes + [self.filterbands.tolist()]
self.filterband_names = epo.names + ['filterband']
self.filterband_units = epo.units + ['Hz']
def calculate_csp(epo, classes=None):
"""Calculate the Common Spatial Pattern (CSP) for two classes.
Now with pattern computation as in matlab bbci toolbox
https://github.com/bbci/bbci_public/blob/c7201e4e42f873cced2e068c6cbb3780a8f8e9ec/processing/proc_csp.m#L112
This method calculates the CSP and the corresponding filters. Use
the columns of the patterns and filters.
Examples
--------
Calculate the CSP for the first two classes::
>>> w, a, d = calculate_csp(epo)
>>> # Apply the first two and the last two columns of the sorted
>>> # filter to the data
>>> filtered = apply_spatial_filter(epo, w[:, [0, 1, -2, -1]])
>>> # You'll probably want to get the log-variance along the time
>>> # axis, this should result in four numbers (one for each
>>> # channel)
>>> filtered = np.log(np.var(filtered, 0))
Select two classes manually::
>>> w, a, d = calculate_csp(epo, [2, 5])
Parameters
----------
epo : epoched Data object
this method relies on the ``epo`` to have three dimensions in
the following order: class, time, channel
classes : list of two ints, optional
If ``None`` the first two different class indices found in
``epo.axes[0]`` are chosen automatically otherwise the class
indices can be manually chosen by setting ``classes``
Returns
-------
v : 2d array
the sorted spatial filters
a : 2d array
the sorted spatial patterns. Column i of a represents the
pattern of the filter in column i of v.
d : 1d array
the variances of the components
Raises
------
AssertionError :
If:
* ``classes`` is not ``None`` and has less than two elements
* ``classes`` is not ``None`` and the first two elements are
not found in the ``epo``
* ``classes`` is ``None`` but there are less than two
different classes in the ``epo``
See Also
--------
:func:`apply_spatial_filter`, :func:`apply_csp`, :func:`calculate_spoc`
References
----------
http://en.wikipedia.org/wiki/Common_spatial_pattern
"""
n_channels = epo.data.shape[-1]
if classes is None:
# automagically find the first two different classidx
# we don't use uniq, since it sorts the classidx first
# first check if we have a least two diffeent idxs:
assert len(np.unique(epo.axes[0])) >= 2
cidx1 = epo.axes[0][0]
cidx2 = epo.axes[0][epo.axes[0] != cidx1][0]
else:
assert (len(classes) >= 2 and
classes[0] in epo.axes[0] and
classes[1] in epo.axes[0])
cidx1 = classes[0]
cidx2 = classes[1]
epoc1 = select_epochs(epo, np.nonzero(epo.axes[0] == cidx1)[0], classaxis=0)
epoc2 = select_epochs(epo, np.nonzero(epo.axes[0] == cidx2)[0], classaxis=0)
# we need a matrix of the form (observations, channels) so we stack trials
# and time per channel together
x1 = epoc1.data.reshape(-1, n_channels)
x2 = epoc2.data.reshape(-1, n_channels)
# compute covariance matrices of the two classes
c1 = np.cov(x1.transpose())
c2 = np.cov(x2.transpose())
# solution of csp objective via generalized eigenvalue problem
# in matlab the signature is v, d = eig(a, b)
d, v = sp.linalg.eig(c1-c2, c1+c2)
d = d.real
# make sure the eigenvalues and -vectors are correctly sorted
indx = np.argsort(d)
# reverse
indx = indx[::-1]
d = d.take(indx)
v = v.take(indx, axis=1)
#old pattern computation
#a = sp.linalg.inv(v).transpose()
c_avg = (c1 + c2) / 2.0
# compare
# https://github.com/bbci/bbci_public/blob/c7201e4e42f873cced2e068c6cbb3780a8f8e9ec/processing/proc_csp.m#L112
# with W := v
v_with_cov = np.dot(c_avg, v)
source_cov = np.dot(np.dot(v.T, c_avg), v)
# matlab-python comparison
"""
v_with_cov = np.array([[1,2,-2],
[3,-2,4],
[5,1,0.3]])
source_cov = np.array([[1,2,0.5],
[2,0.6,4],
[0.5,4,2]])
sp.linalg.solve(source_cov.T, v_with_cov.T).T
# for matlab
v_with_cov = [[1,2,-2],
[3,-2,4],
[5,1,0.3]]
source_cov = [[1,2,0.5],
[2,0.6,4],
[0.5,4,2]]
v_with_cov / source_cov"""
a = sp.linalg.solve(source_cov.T, v_with_cov.T).T
return v, a, d
def calculate_csp(epo, classes=None):
"""Calculate the Common Spatial Pattern (CSP) for two classes.
Now with pattern computation as in matlab bbci toolbox
https://github.com/bbci/bbci_public/blob/c7201e4e42f873cced2e068c6cbb3780a8f8e9ec/processing/proc_csp.m#L112
This method calculates the CSP and the corresponding filters. Use
the columns of the patterns and filters.
Examples
--------
Calculate the CSP for the first two classes::
>>> w, a, d = calculate_csp(epo)
>>> # Apply the first two and the last two columns of the sorted
>>> # filter to the data
>>> filtered = apply_spatial_filter(epo, w[:, [0, 1, -2, -1]])
>>> # You'll probably want to get the log-variance along the time
>>> # axis, this should result in four numbers (one for each
>>> # channel)
>>> filtered = np.log(np.var(filtered, 0))
Select two classes manually::
>>> w, a, d = calculate_csp(epo, [2, 5])
Parameters
----------
epo : epoched Data object
this method relies on the ``epo`` to have three dimensions in
the following order: class, time, channel
classes : list of two ints, optional
If ``None`` the first two different class indices found in
``epo.axes[0]`` are chosen automatically otherwise the class
indices can be manually chosen by setting ``classes``
Returns
-------
v : 2d array
the sorted spatial filters
a : 2d array
the sorted spatial patterns. Column i of a represents the
pattern of the filter in column i of v.
d : 1d array
the variances of the components
Raises
------
AssertionError :
If:
* ``classes`` is not ``None`` and has less than two elements
* ``classes`` is not ``None`` and the first two elements are
not found in the ``epo``
* ``classes`` is ``None`` but there are less than two
different classes in the ``epo``
See Also
--------
:func:`apply_spatial_filter`, :func:`apply_csp`, :func:`calculate_spoc`
References
----------
http://en.wikipedia.org/wiki/Common_spatial_pattern
"""
n_channels = epo.data.shape[-1]
if classes is None:
# automagically find the first two different classidx
# we don't use uniq, since it sorts the classidx first
# first check if we have a least two diffeent idxs:
assert len(np.unique(epo.axes[0])) >= 2
cidx1 = epo.axes[0][0]
cidx2 = epo.axes[0][epo.axes[0] != cidx1][0]
else:
assert (len(classes) >= 2 and classes[0] in epo.axes[0]
and classes[1] in epo.axes[0])
cidx1 = classes[0]
cidx2 = classes[1]
epoc1 = select_epochs(epo,
np.nonzero(epo.axes[0] == cidx1)[0],
classaxis=0)
epoc2 = select_epochs(epo,
np.nonzero(epo.axes[0] == cidx2)[0],
classaxis=0)
# we need a matrix of the form (observations, channels) so we stack trials
# and time per channel together
x1 = epoc1.data.reshape(-1, n_channels)
x2 = epoc2.data.reshape(-1, n_channels)
# compute covariance matrices of the two classes
c1 = np.cov(x1.transpose())
c2 = np.cov(x2.transpose())
# solution of csp objective via generalized eigenvalue problem
# in matlab the signature is v, d = eig(a, b)
d, v = sp.linalg.eig(c1 - c2, c1 + c2)
d = d.real
# make sure the eigenvalues and -vectors are correctly sorted
indx = np.argsort(d)
# reverse
indx = indx[::-1]
d = d.take(indx)
v = v.take(indx, axis=1)
# Now compute patterns
#old pattern computation
#a = sp.linalg.inv(v).transpose()
c_avg = (c1 + c2) / 2.0
# compare
# https://github.com/bbci/bbci_public/blob/c7201e4e42f873cced2e068c6cbb3780a8f8e9ec/processing/proc_csp.m#L112
# with W := v
v_with_cov = np.dot(c_avg, v)
source_cov = np.dot(np.dot(v.T, c_avg), v)
# matlab-python comparison
"""
v_with_cov = np.array([[1,2,-2],
[3,-2,4],
[5,1,0.3]])
source_cov = np.array([[1,2,0.5],
[2,0.6,4],
[0.5,4,2]])
sp.linalg.solve(source_cov.T, v_with_cov.T).T
# for matlab
v_with_cov = [[1,2,-2],
[3,-2,4],
[5,1,0.3]]
source_cov = [[1,2,0.5],
[2,0.6,4],
[0.5,4,2]]
v_with_cov / source_cov"""
a = sp.linalg.solve(source_cov.T, v_with_cov.T).T
return v, a, d
sizes = [20]#np.arange(30, 91, 15) # 4 items
Accuracy = np.zeros((len(sizes), len(starts)))
Accuracy.fill(0.54588)
for i, start in enumerate(starts):
for j, window_size in enumerate(sizes):
train_data = load_epo_data('train', start, window_size)
accuracy = np.zeros(10)
for state in range(0, len(accuracy)):
rs = cross_validation.ShuffleSplit(train_data.data.shape[0], n_iter=10, test_size=.15, random_state=state)
rs = [[train_index, test_index] for train_index, test_index in rs][0]
test_data_i = proc.select_epochs(train_data, rs[1])
train_data_i = proc.select_epochs(train_data, rs[0])
#expected = test_data_i.axes[0]
expected = train_data_i.axes[0]
# creating a CSP filter, preprocessing train data
fv_train, filt = preprocess(train_data_i)
# training LDA
cfy = proc.lda_train(fv_train)
# preprocess test data
#fv_test, _ = preprocess(test_data_i, filt)
# predicting result of the test data
result = proc.lda_apply(fv_train, cfy)
def test_select_epochs_copy(self):
"""Select Epochs must not modify argument."""
cpy = self.dat.copy()
select_epochs(self.dat, [0, 1])
self.assertEqual(self.dat, cpy)
def test_select_epochs_swapaxes(self):
"""Select epochs must work with nonstandard classaxis."""
dat = select_epochs(swapaxes(self.dat, 0, 2), [0, 1], classaxis=2)
dat = swapaxes(dat, 0, 2)
dat2 = select_epochs(self.dat, [0, 1])
self.assertEqual(dat, dat2)
def test_select_epochs_with_cnt(self):
"""Select epochs must raise an exception if called with cnt argument."""
del(self.dat.class_names)
with self.assertRaises(AssertionError):
select_epochs(self.dat, [0, 1])
def subset_data(init_data,
bis_crit=None,
drop_perc=None,
drop_from='beginning',
subj_ids=None,
use_min=None,
use_from=None):
"""Subsets an epoched Data object by BIS value and intra-OP time
It might be useful to only look at data aligned with critical BIS
values (e. g., BIS < 60) or only the second half of the OP.
Params
------
data : wyrm.types.Data
epoched data to subset
bis_crit : int
critical BIS value, drop all epochs with BIS > `bis_crit`
drop_perc : float
percentage of OP to be dropped
drop_from : str
if drop_perc is passed, will drop from beginning or end of OP
* 'beginning': drop from beginning
* 'end': drop from end
use_min : tuple of (start, stop)
only use minutes between use_min[1] and use_min[2],
if use_from == 'beginning' start must be < stop,
if use_from == 'end' start must be > stop
use_from : str
if use_min is passed, will use minute marks at beginning/end of OP
* 'beginning': use_min relative to OP start
* 'end': use_min relative to OP end
Returns
-------
data : wyrm.types.Data
subsetted data
"""
# TODO: Handle drop_perc == None
if subj_ids:
if (not isinstance(subj_ids, np.ndarray)
and not isinstance(subj_ids, list)):
msg = 'When passing `subj_ids`, have to pass list or np.ndarray.'
raise TypeError(msg)
if drop_perc and use_min:
msg = 'Can only use either drop_perc or use_min'
raise ValueError(msg)
data = init_data.copy()
dat = data.data.copy()
subj_id = data.subj_id.copy()
if drop_perc:
if drop_from not in ['beginning', 'end']:
msg = 'drop_from must be one of \'beginning\', \'end\'.'
raise ValueError(msg)
unique_subj_ids = np.unique(subj_id)
idx_to_keep = []
for subj in unique_subj_ids:
idx_subj = np.where(subj_id == subj)[0]
data_subset = dat[idx_subj, :, :].squeeze()
n_epochs = data_subset.shape[0]
n_samples_per_epoch = data_subset.shape[1]
n_samples = n_epochs * n_samples_per_epoch
n_samples_to_drop = drop_perc * n_samples
n_epochs_to_drop = int(
np.floor(n_samples_to_drop / n_samples_per_epoch))
if drop_from == 'beginning':
idx_to_keep.append(idx_subj[n_epochs_to_drop:])
else:
idx_to_keep.append(idx_subj[:-n_epochs_to_drop])
idx_to_keep = np.concatenate(idx_to_keep).ravel()
data = select_epochs(data, indices=idx_to_keep)
data.subj_id = data.subj_id[idx_to_keep]
data.bis = data.bis[idx_to_keep]
if use_min:
if use_from not in ['beginning', 'end']:
msg = 'use_from must be one of \'beginning\', \'end\'.'
raise ValueError(msg)
unique_subj_ids = np.unique(subj_id)
idx_to_keep = []
for subj in unique_subj_ids:
idx_subj = np.where(subj_id == subj)[0]
data_subset = dat[idx_subj, :, :].squeeze()
n_samples_per_epoch = data_subset.shape[1]
n_samples_to_keep = (max(use_min) - min(use_min)) * 60 * data.fs
n_epochs_to_keep = int(
np.floor(n_samples_to_keep / n_samples_per_epoch))
if use_from == 'beginning':
n_samples_to_drop_before = min(use_min) * 60 * data.fs
n_epochs_to_drop_before = int(
np.floor(n_samples_to_drop_before / n_samples_per_epoch))
idx_to_keep.append(
idx_subj[n_epochs_to_drop_before:n_epochs_to_drop_before +
n_epochs_to_keep])
elif use_from == 'end':
n_samples_to_drop_after = min(use_min) * 60 * data.fs
n_epochs_to_drop_after = int(
np.floor(n_samples_to_drop_after / n_samples_per_epoch))
start = -n_epochs_to_drop_after - n_epochs_to_keep
stop = -n_epochs_to_drop_after if n_epochs_to_drop_after != 0 else -1
idx_to_keep.append(idx_subj[start:stop])
idx_to_keep = np.concatenate(idx_to_keep).ravel()
data = select_epochs(data, indices=idx_to_keep)
data.subj_id = data.subj_id[idx_to_keep]
data.bis = data.bis[idx_to_keep]
dat = data.data.copy()
bis = data.bis.copy()
axes = data.axes.copy()
subj_id = data.subj_id.copy()
# only keep windows where BIS <= bis_crit
if bis_crit:
new_idx = np.where(np.all(bis <= bis_crit, axis=1))
dat = dat[new_idx]
bis = bis[new_idx]
axes[0] = axes[0][new_idx]
subj_id = subj_id[new_idx]
data.data = dat
data.bis = bis
data.axes = axes
data.subj_id = subj_id
if subj_ids:
mask = np.isin(data.subj_id, subj_ids)
data.subj_id = data.subj_id[mask]
dat = data.data.compress(mask, 0) # classaxis is 0
axes = data.axes[:]
axes[0] = data.axes[0].compress(mask)
data = data.copy(data=dat, axes=axes)
return data
n_epo_per_sub = 5440 / len(train_subs)
def epochs_indices(subj_indices):
return np.hstack([np.arange(s_ind * n_epo_per_sub, (s_ind + 1) * n_epo_per_sub) for s_ind in subj_indices])
for i, start in enumerate(starts):
for j, window_size in enumerate(sizes):
accuracy = np.zeros(20)
train_data = load_epo_data('train', start, window_size)
for state in range(0, len(accuracy)):
rs = cross_validation.ShuffleSplit(len(train_subs), n_iter=10, test_size=.15, random_state=state)
rs = [[train_index, test_index] for train_index, test_index in rs][0]
train_data_i = proc.select_epochs(train_data, epochs_indices(rs[0]))
test_data_i = proc.select_epochs(train_data, epochs_indices(rs[1]))
expected = test_data_i.axes[0]
# creating a CSP filter, preprocessing train data
fv_train, filt = preprocess(train_data_i)
# training LDA
cfy = proc.lda_train(fv_train)
# preprocess test data
fv_test, _ = preprocess(test_data_i, filt)
# predicting result of the test data
result = proc.lda_apply(fv_test, cfy)
