示例#1
0
文件: mvpa.py 项目: maximovs/ieeglab
def calculate_generalization_across_time_decoding(epochs, picked_channels, y,
                                                  fold_nr, resamplefreq,
                                                  outputfile):

    if picked_channels:
        epochs.pick_channels(picked_channels)
    else:
        print 'no channels to pick'

    if resamplefreq:
        #resample
        epochs.resample(resamplefreq,
                        npad=100,
                        window='boxcar',
                        n_jobs=1,
                        copy=False,
                        verbose=None)

    cv = StratifiedKFold(y=y,
                         n_folds=fold_nr)  # do a stratified cross-validation
    gat = GeneralizationAcrossTime(predict_mode='cross-validation',
                                   n_jobs=1,
                                   cv=cv,
                                   scorer=roc_auc_score,
                                   score_mode='fold-wise')

    # fit and score
    gat.fit(epochs, y=y)
    scores = gat.score(epochs)
    if outputfile:
        scipy.io.savemat(outputfile, {'scores': scores})

    print('GAT DONE')
    return scores
示例#2
0
def _get_data():
    """Aux function for testing GAT viz"""
    gat = GeneralizationAcrossTime()
    raw = io.Raw(raw_fname, preload=False)
    events = read_events(event_name)
    picks = pick_types(raw.info,
                       meg='mag',
                       stim=False,
                       ecg=False,
                       eog=False,
                       exclude='bads')
    picks = picks[1:13:3]
    decim = 30
    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw,
                        events,
                        event_id,
                        tmin,
                        tmax,
                        picks=picks,
                        baseline=(None, 0),
                        preload=True,
                        decim=decim)

    # Test default running
    gat = GeneralizationAcrossTime()
    gat.fit(epochs)
    gat.score(epochs)
    return gat
示例#3
0
def quick_score(X, y, clf=None, scorer=None):
    from sklearn.cross_validation import KFold
    regression = (len(np.unique(y)) > 2) & isinstance(y[0], float)
    if scorer is None:
        scorer = scorer_spearman if regression else scorer_auc
    if clf is None:
        clf = RidgeCV(alphas=[(2 * C) ** -1 for C in [1e-4, 1e-2, 1]])\
            if regression else force_predict(LogisticRegression(), axis=1)
    sel = np.where(~np.isnan(y))[0]
    X = X[sel, :, :]
    y = y[sel]
    epochs = mat2mne(X, sfreq=100)
    clf = make_pipeline(StandardScaler(), clf)
    cv = KFold(len(y), 5) if regression else None
    gat = GeneralizationAcrossTime(clf=clf, n_jobs=-1, scorer=scorer, cv=cv)
    gat.fit(epochs, y)
    gat.score(epochs, y)
    return gat
def _run(epochs, events, analysis):
    """Runs temporal generalization for a given subject and analysis"""
    print(subject, analysis['name'])

    # subselect the trials (e.g. exclude absent trials) with a
    # dataframe query defined in conditions.py
    query, condition = analysis['query'], analysis['condition']
    sel = range(len(events)) if query is None \
        else events.query(query).index
    sel = [ii for ii in sel if ~np.isnan(events[condition][sel][ii])]

    # The to-be-predicted value, for each trial:
    y = np.array(events[condition], dtype=np.float32)

    print analysis['name'], np.unique(y[sel]), len(sel)

    # Abort if there is no trial
    if len(sel) == 0:
        return

    # Apply analysis
    gat = GeneralizationAcrossTime(clf=analysis['clf'],
                                   cv=analysis['cv'],
                                   scorer=analysis['scorer'],
                                   n_jobs=-1)
    print(subject, analysis['name'], 'fit')
    gat.fit(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'score')
    score = gat.score(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'save')

    # save space
    if analysis['name'] not in ['probe_phase', 'target_circAngle']:
        # we'll need the estimator trained on the probe_phase and to generalize
        # to the target phase and prove that there is a significant signal.
        gat.estimators_ = None
    if analysis['name'] not in [
            'target_present', 'target_circAngle', 'probe_circAngle'
    ]:
        # We need these individual prediction to control for the correlation
        # between target and probe angle.
        gat.y_pred_ = None

    # Save analysis
    save([gat, analysis, sel, events],
         'decod',
         subject=subject,
         analysis=analysis['name'],
         overwrite=True,
         upload=True)
    save([score, epochs.times],
         'score',
         subject=subject,
         analysis=analysis['name'],
         overwrite=True,
         upload=True)
    return
示例#5
0
def _get_data(tmin=-0.2, tmax=0.5, event_id=dict(aud_l=1, vis_l=3),
              event_id_gen=dict(aud_l=2, vis_l=4), test_times=None):
    """Aux function for testing GAT viz."""
    with warnings.catch_warnings(record=True):  # deprecated
        gat = GeneralizationAcrossTime()
    raw = read_raw_fif(raw_fname)
    raw.add_proj([], remove_existing=True)
    events = read_events(event_name)
    picks = pick_types(raw.info, meg='mag', stim=False, ecg=False,
                       eog=False, exclude='bads')
    picks = picks[1:13:3]
    decim = 30
    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                        preload=True, decim=decim)
    epochs_list = [epochs[k] for k in event_id]
    equalize_epoch_counts(epochs_list)
    epochs = concatenate_epochs(epochs_list)

    # Test default running
    with warnings.catch_warnings(record=True):  # deprecated
        gat = GeneralizationAcrossTime(test_times=test_times)
    gat.fit(epochs)
    gat.score(epochs)
    return gat
def decoding_analysis(c1, c2):
    c1.events[:, 2] = 0
    c2.events[:, 2] = 1
    c1.event_id['exp_sup_lon'] = 0
    c2.event_id['exp_sup_sho'] = 1
    epochs = mne.concatenate_epochs([c1, c2])

    # td = TimeDecoding(predict_mode='cross-validation', n_jobs=1, scorer=roc_auc_score)
    # td.fit(epochs)
    # td.score(epochs)
    # td.plot('Subject: ', c1.info['subject_info'], chance=True)

    # GAT
    y = epochs.events[:, 2]
    # y = np.zeros(len(epochs.events), dtype=int)
    # y[epochs.events[:, 2] == 90] = 1
    cv = StratifiedKFold(y=y)  # do a stratified cross-validation

    gat = GeneralizationAcrossTime(predict_mode='cross-validation', n_jobs=1,
                                   cv=cv, scorer=roc_auc_score)

    # fit and score
    gat.fit(epochs, y=y)
    gat.score(epochs)

    # # plot
    # gat.plot(vmin=0, vmax=1)
    # gat.plot_diagonal()
    return gat
def _decod(subject, analysis):
    from mne.decoding import GeneralizationAcrossTime

    # if already computed let's just load it from disk
    fname_kwargs = dict(subject=subject, analysis=analysis['name'] + '_vhp')
    score_fname = paths('score', **fname_kwargs)
    if op.exists(score_fname):
        return load('score', **fname_kwargs)

    epochs = _get_epochs(subject)
    events = load('behavior', subject=subject)

    # Let's not recompute everything, this is just a control analysis
    print(subject, analysis['name'])
    epochs._data = epochs.get_data()
    epochs.preload = True
    epochs.crop(0., .900)
    epochs.decimate(2)

    query, condition = analysis['query'], analysis['condition']
    sel = range(len(events)) if query is None else events.query(query).index
    sel = [ii for ii in sel if ~np.isnan(events[condition][sel][ii])]
    y = np.array(events[condition], dtype=np.float32)

    print analysis['name'], np.unique(y[sel]), len(sel)

    if len(sel) == 0:
        return

    # Apply analysis
    gat = GeneralizationAcrossTime(clf=analysis['clf'],
                                   cv=analysis['cv'],
                                   scorer=analysis['scorer'],
                                   n_jobs=-1)
    print(subject, analysis['name'], 'fit')
    gat.fit(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'score')
    score = gat.score(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'save')

    # save space
    gat.estimators_ = None
    gat.y_pred_ = None

    # Save analysis
    save([score, epochs.times],
         'score',
         overwrite=True,
         upload=True,
         **fname_kwargs)
    return score, epochs.times
def _run(epochs, events, analysis):
    """Runs temporal generalization for a given subject and analysis"""
    print(subject, analysis['name'])

    # subselect the trials (e.g. exclude absent trials) with a
    # dataframe query defined in conditions.py
    query, condition = analysis['query'], analysis['condition']
    sel = range(len(events)) if query is None \
        else events.query(query).index
    sel = [ii for ii in sel if ~np.isnan(events[condition][sel][ii])]

    # The to-be-predicted value, for each trial:
    y = np.array(events[condition], dtype=np.float32)

    print analysis['name'], np.unique(y[sel]), len(sel)

    # Abort if there is no trial
    if len(sel) == 0:
        return

    # Apply analysis
    gat = GeneralizationAcrossTime(clf=analysis['clf'],
                                   cv=analysis['cv'],
                                   scorer=analysis['scorer'],
                                   n_jobs=-1)
    print(subject, analysis['name'], 'fit')
    gat.fit(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'score')
    score = gat.score(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'save')

    # save space
    if analysis['name'] not in ['probe_phase', 'target_circAngle']:
        # we'll need the estimator trained on the probe_phase and to generalize
        # to the target phase and prove that there is a significant signal.
        gat.estimators_ = None
    if analysis['name'] not in ['target_present', 'target_circAngle',
                                'probe_circAngle']:
        # We need these individual prediction to control for the correlation
        # between target and probe angle.
        gat.y_pred_ = None

    # Save analysis
    save([gat, analysis, sel, events], 'decod',
         subject=subject, analysis=analysis['name'], overwrite=True,
         upload=True)
    save([score, epochs.times], 'score',
         subject=subject, analysis=analysis['name'], overwrite=True,
         upload=True)
    return
示例#9
0
def _get_data(tmin=-0.2,
              tmax=0.5,
              event_id=dict(aud_l=1, vis_l=3),
              event_id_gen=dict(aud_l=2, vis_l=4),
              test_times=None):
    """Aux function for testing GAT viz"""
    gat = GeneralizationAcrossTime()
    raw = read_raw_fif(raw_fname, preload=False, add_eeg_ref=False)
    raw.add_proj([], remove_existing=True)
    events = read_events(event_name)
    picks = pick_types(raw.info,
                       meg='mag',
                       stim=False,
                       ecg=False,
                       eog=False,
                       exclude='bads')
    picks = picks[1:13:3]
    decim = 30
    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw,
                        events,
                        event_id,
                        tmin,
                        tmax,
                        picks=picks,
                        baseline=(None, 0),
                        preload=True,
                        decim=decim,
                        add_eeg_ref=False)
    epochs_list = [epochs[k] for k in event_id]
    equalize_epoch_counts(epochs_list)
    epochs = concatenate_epochs(epochs_list)

    # Test default running
    gat = GeneralizationAcrossTime(test_times=test_times)
    gat.fit(epochs)
    gat.score(epochs)
    return gat
def _decod(subject, analysis):
    from mne.decoding import GeneralizationAcrossTime

    # if already computed let's just load it from disk
    fname_kwargs = dict(subject=subject, analysis=analysis['name'] + '_vhp')
    score_fname = paths('score', **fname_kwargs)
    if op.exists(score_fname):
        return load('score', **fname_kwargs)

    epochs = _get_epochs(subject)
    events = load('behavior', subject=subject)

    # Let's not recompute everything, this is just a control analysis
    print(subject, analysis['name'])
    epochs._data = epochs.get_data()
    epochs.preload = True
    epochs.crop(0., .900)
    epochs.decimate(2)

    query, condition = analysis['query'], analysis['condition']
    sel = range(len(events)) if query is None else events.query(query).index
    sel = [ii for ii in sel if ~np.isnan(events[condition][sel][ii])]
    y = np.array(events[condition], dtype=np.float32)

    print analysis['name'], np.unique(y[sel]), len(sel)

    if len(sel) == 0:
        return

    # Apply analysis
    gat = GeneralizationAcrossTime(clf=analysis['clf'],
                                   cv=analysis['cv'],
                                   scorer=analysis['scorer'],
                                   n_jobs=-1)
    print(subject, analysis['name'], 'fit')
    gat.fit(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'score')
    score = gat.score(epochs[sel], y=y[sel])
    print(subject, analysis['name'], 'save')

    # save space
    gat.estimators_ = None
    gat.y_pred_ = None

    # Save analysis
    save([score, epochs.times], 'score', overwrite=True, upload=True,
         **fname_kwargs)
    return score, epochs.times
示例#11
0
def quick_score(X, y, clf=None, scorer=None):
    from sklearn.cross_validation import KFold
    regression = (len(np.unique(y)) > 2) & isinstance(y[0], float)
    if scorer is None:
        scorer = scorer_spearman if regression else scorer_auc
    if clf is None:
        clf = RidgeCV(alphas=[(2 * C) ** -1 for C in [1e-4, 1e-2, 1]])\
            if regression else force_predict(LogisticRegression(), axis=1)
    sel = np.where(~np.isnan(y))[0]
    X = X[sel, :, :]
    y = y[sel]
    epochs = mat2mne(X, sfreq=100)
    clf = make_pipeline(StandardScaler(), clf)
    cv = KFold(len(y), 5) if regression else None
    gat = GeneralizationAcrossTime(clf=clf, n_jobs=-1, scorer=scorer, cv=cv)
    gat.fit(epochs, y)
    gat.score(epochs, y)
    return gat
示例#12
0
def _get_data():
    """Aux function for testing GAT viz"""
    gat = GeneralizationAcrossTime()
    raw = io.Raw(raw_fname, preload=False)
    events = read_events(event_name)
    picks = pick_types(raw.info, meg='mag', stim=False, ecg=False,
                       eog=False, exclude='bads')
    picks = picks[1:13:3]
    decim = 30
    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                        baseline=(None, 0), preload=True, decim=decim)

    # Test default running
    gat = GeneralizationAcrossTime()
    gat.fit(epochs)
    gat.score(epochs)
    return gat
info = create_info(chan_names, 1, chan_types)
events = np.c_[np.cumsum(np.ones(n_trial)), np.zeros(n_trial), np.zeros(n_trial)]
epochs = EpochsArray(data, info, events)

# RUN GAT ======================================================================

# SVR
# --- fit & predict separately
cos = lambda angles: np.cos(angle2circle(angles))
sin = lambda angles: np.sin(angle2circle(angles))
gats = list()
for transform in [cos, sin]:
    scaler = StandardScaler()
    svr = SVR(C=1, kernel='linear')
    clf = Pipeline([('scaler', scaler), ('svr', svr)])
    gat = GeneralizationAcrossTime(n_jobs=-1, clf=clf)
    gat.fit(epochs, y=transform(trial_angles))
    gat.predict(epochs)
    gats.append(gat)
# --- recombine
predict_angles, true_angles = recombine_svr_prediction(gats[0], gats[1])
# --- score
angle_errors_svr = compute_error_svr(predict_angles, true_angles)
plt.matshow(np.mean(angle_errors_svr,axis=2)), plt.colorbar(), plt.show()


# SVC Gat
scaler = StandardScaler()
svc = SVC(C=1, kernel='linear', probability=True)
clf = Pipeline([('scaler', scaler), ('svc', svc)])
gat = GeneralizationAcrossTime(n_jobs=-1, clf=clf, predict_type='predict_proba')
示例#14
0
def test_circular_classifiers():
    from mne.decoding import GeneralizationAcrossTime
    from ..scorers import scorer_angle
    from sklearn.linear_model import Ridge, RidgeCV
    epochs, angles = make_circular_data()
    clf_list = [PolarRegression, AngularRegression, SVR_polar,
                SVR_angle]  # XXX will be deprecated
    for clf_init in clf_list:
        for independent in [False, True]:
            if clf_init in [SVR_polar, SVR_angle]:
                if (not independent):
                    continue
                clf = clf_init(clf=Ridge(random_state=0))
            else:
                clf = clf_init(clf=Ridge(random_state=0),
                               independent=independent)
            print clf_init, independent
            gat = GeneralizationAcrossTime(clf=clf, scorer=scorer_angle)
            gat.fit(epochs, y=angles)
            gat.predict(epochs)
            gat.score(y=angles)
            assert_true(np.abs(gat.scores_[0][0]) < .5)  # chance level
            assert_true(gat.scores_[1][1] > 1.)  # decode
            assert_true(gat.scores_[2][2] > 1.)  # decode
            assert_true(gat.scores_[1][2] < -1.)  # anti-generalize
    # Test args
    gat = GeneralizationAcrossTime(clf=RidgeCV(alphas=[1., 2.]),
                                   scorer=scorer_angle)
    gat.fit(epochs, y=angles)
    gat = GeneralizationAcrossTime(clf=RidgeCV(), scorer=scorer_angle)
    gat.fit(epochs, y=angles)
#
## We define the epochs and the labels
n_cond1 = len(epochs_clas[event_id[0]])
n_cond2 = len(epochs_clas[event_id[1]])
y = np.r_[np.ones((n_cond1, )), np.zeros((n_cond2, ))]

#------------------Start of Decoding Script --------------

cv = StratifiedKFold(y=y)  # do a stratified cross-validation

# define the GeneralizationAcrossTime object
train_times = {'start': -0.1, 'stop': 2}

gat = GeneralizationAcrossTime(predict_mode='cross-validation',
                               train_times=train_times,
                               n_jobs=6,
                               cv=cv,
                               scorer=roc_auc_score)

# fit and score
print("Fitting")
gat.fit(epochs_clas, y=y)
print("Scoring")
gat.score(epochs_clas)

# let's visualize now
gat.plot()
gat.plot_diagonal()

# ------------------------------
# Time Decoding Generalization
示例#16
0
mne.epochs.equalize_epoch_counts([epochs_classic, epochs_plan])

# Dirty hack # TODO: Check this from the Maxfilter side
# epochs_classic.info['dev_head_t'] = epochs_plan.info['dev_head_t']

epochs = mne.concatenate_epochs([epochs_classic, epochs_plan])

# Crop and downsmample to make it faster
epochs.crop(tmin=-3.5, tmax=0)
epochs.resample(250)

# Setup the y vector and GAT
y = np.concatenate(
    (np.zeros(len(epochs["press"])), np.ones(len(epochs["plan"]))))
gat = GeneralizationAcrossTime(predict_mode='mean-prediction',
                               scorer="roc_auc",
                               n_jobs=1)

# Fit model

# Scoring and visualise result
gat.score(epochs, y=y)

# Save model
joblib.dump(gat, data_path + "decode_time_gen/%s_gat_2.jl" % subject)

fig = gat.plot(
    title="Temporal Gen (Classic vs planning): left to right sub: %s" %
    subject)
fig.savefig(data_path + "decode_time_gen/%s_gat_matrix_2.png" % subject)
            query, condition = analysis['query'], analysis['condition']
            sel = range(len(events)) if query is None \
                else events.query(query).index
            sel = [ii for ii in sel if ~np.isnan(events[condition][sel][ii])]
            y = np.array(events[condition], dtype=np.float32)

            print analysis['name'], np.unique(y[sel]), len(sel)

            if len(sel) == 0:
                logger.warning('%s: no epoch in %s for %s.' % (
                    subject, data_type, analysis['name']))
                continue

            # Apply analysis
            gat = GeneralizationAcrossTime(clf=analysis['clf'],
                                           cv=analysis['cv'],
                                           scorer=analysis['scorer'],
                                           n_jobs=-1)
            gat.fit(epochs[sel], y=y[sel])
            gat.score(epochs[sel], y=y[sel])

            # Save analysis
            pkl_fname = paths('decod', subject=subject, data_type=data_type,
                              analysis=analysis['name'], log=True)

            # Save classifier results
            with open(pkl_fname, 'wb') as f:
                pickle.dump([gat, analysis, sel, events], f)

            # Plot
            fig = gat.plot_diagonal(show=False)
            report.add_figs_to_section(fig, ('%s %s %s: (diagonal)' %
events = mne.find_events(raw, stim_channel='UPPT001')
event_id = {"faces": 1, "scrambled": 2}
tmin, tmax = -0.1, 0.5

decim = 4  # decimate to make the example faster to run
epochs = mne.Epochs(raw,
                    events,
                    event_id,
                    tmin,
                    tmax,
                    proj=True,
                    picks=picks,
                    baseline=None,
                    preload=True,
                    reject=dict(mag=1.5e-12),
                    decim=decim,
                    verbose=False)

# Define decoder. The decision_function is employed to use AUC for scoring
gat = GeneralizationAcrossTime(predict_mode='cross-validation',
                               predict_type='decision_function',
                               n_jobs=2)

# fit and score
gat.fit(epochs)
gat.score(epochs)
gat.plot(vmin=0.1,
         vmax=0.9,
         title="Generalization Across Time (faces vs. scrambled)")
gat.plot_diagonal()  # plot decoding across time (correspond to GAT diagonal)
                    preload=True,
                    reject=dict(mag=5e-12),
                    decim=decim,
                    verbose=False)

# We will train the classifier on all left visual vs auditory trials
# and test on all right visual vs auditory trials.

# In this case, because the test data is independent from the train data,
# we test the classifier of each fold and average the respective predictions.

# Define events of interest
triggers = epochs.events[:, 2]
viz_vs_auditory = np.in1d(triggers, (1, 2)).astype(int)

gat = GeneralizationAcrossTime(predict_mode='mean-prediction', n_jobs=1)

# For our left events, which ones are visual?
viz_vs_auditory_l = (triggers[np.in1d(triggers, (1, 3))] == 3).astype(int)
# To make scikit-learn happy, we converted the bool array to integers
# in the same line. This results in an array of zeros and ones:
print("The unique classes' labels are: %s" % np.unique(viz_vs_auditory_l))

gat.fit(epochs[('AudL', 'VisL')], y=viz_vs_auditory_l)

# For our right events, which ones are visual?
viz_vs_auditory_r = (triggers[np.in1d(triggers, (2, 4))] == 4).astype(int)

gat.score(epochs[('AudR', 'VisR')], y=viz_vs_auditory_r)
gat.plot(title="Temporal Generalization (visual vs auditory): left to right")
示例#20
0
###############################################################################
# Generalization Across Time
# --------------------------
#
# This runs the analysis used in [1]_ and further detailed in [2]_
#
# Here we'll use a stratified cross-validation scheme.

# make response vector
y = np.zeros(len(epochs.events), dtype=int)
y[epochs.events[:, 2] == 3] = 1
cv = StratifiedKFold(y=y)  # do a stratified cross-validation

# define the GeneralizationAcrossTime object
gat = GeneralizationAcrossTime(predict_mode='cross-validation',
                               n_jobs=1,
                               cv=cv,
                               scorer=roc_auc_score)

# fit and score
gat.fit(epochs, y=y)
gat.score(epochs)

# let's visualize now
gat.plot()
gat.plot_diagonal()

###############################################################################
# Exercise
# --------
#  - Can you improve the performance using full epochs and a common spatial
#    pattern (CSP) used by most BCI systems?
示例#21
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC
    from sklearn.base import is_classifier
    # KernelRidge is used for testing 1) regression analyses 2) n-dimensional
    # predictions.
    from sklearn.kernel_ridge import KernelRidge
    from sklearn.preprocessing import LabelEncoder
    from sklearn.metrics import roc_auc_score, mean_squared_error

    epochs = make_epochs()
    y_4classes = np.hstack((epochs.events[:7, 2], epochs.events[7:, 2] + 1))
    if check_version('sklearn', '0.18'):
        from sklearn.model_selection import (KFold, StratifiedKFold,
                                             ShuffleSplit, LeaveOneLabelOut)
        cv_shuffle = ShuffleSplit()
        cv = LeaveOneLabelOut()
        # XXX we cannot pass any other parameters than X and y to cv.split
        # so we have to build it before hand
        cv_lolo = [(train, test) for train, test in cv.split(
            X=y_4classes, y=y_4classes, labels=y_4classes)]

        # With sklearn >= 0.17, `clf` can be identified as a regressor, and
        # the scoring metrics can therefore be automatically assigned.
        scorer_regress = None
    else:
        from sklearn.cross_validation import (KFold, StratifiedKFold,
                                              ShuffleSplit, LeaveOneLabelOut)
        cv_shuffle = ShuffleSplit(len(epochs))
        cv_lolo = LeaveOneLabelOut(y_4classes)

        # With sklearn < 0.17, `clf` cannot be identified as a regressor, and
        # therefore the scoring metrics cannot be automatically assigned.
        scorer_regress = mean_squared_error
    # Test default running
    gat = GeneralizationAcrossTime(picks='foo')
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    assert_raises(ValueError, gat.fit, epochs)
    with warnings.catch_warnings(record=True):
        # check classic fit + check manual picks
        gat.picks = [0]
        gat.fit(epochs)
        # check optional y as array
        gat.picks = None
        gat.fit(epochs, y=epochs.events[:, 2])
        # check optional y as list
        gat.fit(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(len(gat.picks_), len(gat.ch_names), 1)
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
        "prediction, no score>", '%s' % gat)
    assert_equal(gat.ch_names, epochs.ch_names)
    # test different predict function:
    gat = GeneralizationAcrossTime(predict_method='decision_function')
    gat.fit(epochs)
    # With classifier, the default cv is StratifiedKFold
    assert_true(gat.cv_.__class__ == StratifiedKFold)
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 15, 14, 1))
    gat.predict_method = 'predict_proba'
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 15, 14, 2))
    gat.predict_method = 'foo'
    assert_raises(NotImplementedError, gat.predict, epochs)
    gat.predict_method = 'predict'
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 15, 14, 1))
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
        "predicted 14 epochs, no score>", "%s" % gat)
    gat.score(epochs)
    assert_true(gat.scorer_.__name__ == 'accuracy_score')
    # check clf / predict_method combinations for which the scoring metrics
    # cannot be inferred.
    gat.scorer = None
    gat.predict_method = 'decision_function'
    assert_raises(ValueError, gat.score, epochs)
    # Check specifying y manually
    gat.predict_method = 'predict'
    gat.score(epochs, y=epochs.events[:, 2])
    gat.score(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
        "predicted 14 epochs,\n scored "
        "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal(
        "<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
        "0.050 (s), length: 0.050 (s), n_time_windows: 15>",
        "%s" % gat.train_times_)
    assert_equal(
        "<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
        "0.050 (s), length: 0.050 (s), n_time_windows: 15 x 15>",
        "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    gat_ = copy.deepcopy(gat)
    with use_log_level('error'):
        assert_raises(ValueError, gat_.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] == gat.y_true_.shape[0] == len(
        gat.y_pred_[0][0]) == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(
        len(gat.train_times_['slices']) == 15 == np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(
        len(gat.test_times_['slices']) == 15 == np.shape(gat.scores_)[0])
    assert_true(
        len(gat.test_times_['slices'][0]) == 15 == np.shape(gat.scores_)[1])

    # Test score_mode
    gat.score_mode = 'foo'
    assert_raises(ValueError, gat.score, epochs)
    gat.score_mode = 'fold-wise'
    scores = gat.score(epochs)
    assert_array_equal(np.shape(scores), [15, 15, 5])
    gat.score_mode = 'mean-sample-wise'
    scores = gat.score(epochs)
    assert_array_equal(np.shape(scores), [15, 15])
    gat.score_mode = 'mean-fold-wise'
    scores = gat.score(epochs)
    assert_array_equal(np.shape(scores), [15, 15])
    gat.predict_mode = 'mean-prediction'
    with warnings.catch_warnings(record=True) as w:
        gat.score(epochs)
        assert_true(
            any("score_mode changed from " in str(ww.message) for ww in w))

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    with warnings.catch_warnings(record=True):  # not vectorizing
        scores = gat.score(epochs)
    assert_true(isinstance(scores, np.ndarray))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check
    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.score(epochs)
    assert_true(len(gat.scores_) == len(gat.estimators_) == 8)  # training time
    assert_equal(len(gat.scores_[0]), 15)  # testing time

    # Test start stop training & test cv without n_fold params
    y_4classes = np.hstack((epochs.events[:7, 2], epochs.events[7:, 2] + 1))
    train_times = dict(start=0.090, stop=0.250)
    gat = GeneralizationAcrossTime(cv=cv_lolo, train_times=train_times)
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=y_4classes)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times_['times'][0], epochs.times[6])
    assert_equal(gat.train_times_['times'][-1], epochs.times[9])

    # Test score without passing epochs & Test diagonal decoding
    gat = GeneralizationAcrossTime(test_times='diagonal')
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.fit(epochs)
    assert_raises(RuntimeError, gat.score)
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.predict(epochs)
    scores = gat.score()
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))
    assert_array_equal(
        [tim for ttime in gat.test_times_['times'] for tim in ttime],
        gat.train_times_['times'])
    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction', cv=2)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    with warnings.catch_warnings(record=True):
        # There are some empty test folds because of n_trials
        gat.predict(epochs[7:])
        gat.score(epochs[7:])

    # Test training time parameters
    gat_ = copy.deepcopy(gat)
    # --- start stop outside time range
    gat_.train_times = dict(start=-999.)
    with use_log_level('error'):
        assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(start=999.)
    assert_raises(ValueError, gat_.fit, epochs)
    # --- impossible slices
    gat_.train_times = dict(step=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=999.)
    assert_raises(ValueError, gat_.fit, epochs)

    # Test testing time parameters
    # --- outside time range
    gat.test_times = dict(start=-999.)
    with warnings.catch_warnings(record=True):  # no epochs in fold
        assert_raises(ValueError, gat.predict, epochs)
    gat.test_times = dict(start=999.)
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat.predict, epochs)
    # --- impossible slices
    gat.test_times = dict(step=.000001)
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat.predict, epochs)
    gat_ = copy.deepcopy(gat)
    gat_.train_times_['length'] = .000001
    gat_.test_times = dict(length=.000001)
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat_.predict, epochs)
    # --- test time region of interest
    gat.test_times = dict(step=.150)
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 5, 14, 1))
    # --- silly value
    gat.test_times = 'foo'
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat.predict, epochs)
    assert_raises(RuntimeError, gat.score)
    # --- unmatched length between training and testing time
    gat.test_times = dict(length=.150)
    assert_raises(ValueError, gat.predict, epochs)
    # --- irregular length training and testing times
    # 2 estimators, the first one is trained on two successive time samples
    # whereas the second one is trained on a single time sample.
    train_times = dict(slices=[[0, 1], [1]])
    # The first estimator is tested once, the second estimator is tested on
    # two successive time samples.
    test_times = dict(slices=[[[0, 1]], [[0], [1]]])
    gat = GeneralizationAcrossTime(train_times=train_times,
                                   test_times=test_times)
    gat.fit(epochs)
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.score(epochs)
    assert_array_equal(np.shape(gat.y_pred_[0]), [1, len(epochs), 1])
    assert_array_equal(np.shape(gat.y_pred_[1]), [2, len(epochs), 1])
    # check cannot Automatically infer testing times for adhoc training times
    gat.test_times = None
    assert_raises(ValueError, gat.predict, epochs)

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc, predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    with use_log_level('error'):
        assert_raises(ValueError, gat.score, epochs2)
        gat.score(epochs)
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime(cv=cv_shuffle)
    gat.fit(epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.predict(epochs)
    assert_raises(ValueError, gat.predict, epochs[:10])

    # Make CV with some empty train and test folds:
    # --- empty test fold(s) should warn when gat.predict()
    gat._cv_splits[0] = [gat._cv_splits[0][0], np.empty(0)]
    with warnings.catch_warnings(record=True) as w:
        gat.predict(epochs)
        assert_true(len(w) > 0)
        assert_true(
            any('do not have any test epochs' in str(ww.message) for ww in w))
    # --- empty train fold(s) should raise when gat.fit()
    gat = GeneralizationAcrossTime(cv=[([0], [1]), ([], [0])])
    assert_raises(ValueError, gat.fit, epochs[:2])

    # Check that still works with classifier that output y_pred with
    # shape = (n_trials, 1) instead of (n_trials,)
    if check_version('sklearn', '0.17'):  # no is_regressor before v0.17
        gat = GeneralizationAcrossTime(clf=KernelRidge(), cv=2)
        epochs.crop(None, epochs.times[2])
        gat.fit(epochs)
        # With regression the default cv is KFold and not StratifiedKFold
        assert_true(gat.cv_.__class__ == KFold)
        gat.score(epochs)
        # with regression the default scoring metrics is mean squared error
        assert_true(gat.scorer_.__name__ == 'mean_squared_error')

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2, 4]  # 4 tested
    # nicely ordered labels or not
    le = LabelEncoder()
    y = le.fit_transform(epochs.events[:, 2])
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Univariate and multivariate prediction
    svc = SVC(C=1, kernel='linear', probability=True)
    reg = KernelRidge()

    def scorer_proba(y_true, y_pred):
        return roc_auc_score(y_true, y_pred[:, 0])

    # We re testing 3 scenario: default, classifier + predict_proba, regressor
    scorers = [None, scorer_proba, scorer_regress]
    predict_methods = [None, 'predict_proba', None]
    clfs = [svc, svc, reg]
    # Test all combinations
    for clf, predict_method, scorer in zip(clfs, predict_methods, scorers):
        for y in ys:
            for n_class in n_classes:
                for predict_mode in ['cross-validation', 'mean-prediction']:
                    # Cannot use AUC for n_class > 2
                    if (predict_method == 'predict_proba' and n_class != 2):
                        continue

                    y_ = y % n_class

                    with warnings.catch_warnings(record=True):
                        gat = GeneralizationAcrossTime(
                            cv=2,
                            clf=clf,
                            scorer=scorer,
                            predict_mode=predict_mode)
                        gat.fit(epochs, y=y_)
                        gat.score(epochs, y=y_)

                    # Check that scorer is correctly defined manually and
                    # automatically.
                    scorer_name = gat.scorer_.__name__
                    if scorer is None:
                        if is_classifier(clf):
                            assert_equal(scorer_name, 'accuracy_score')
                        else:
                            assert_equal(scorer_name, 'mean_squared_error')
                    else:
                        assert_equal(scorer_name, scorer.__name__)
示例#22
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC

    raw = io.Raw(raw_fname, preload=False)
    events = read_events(event_name)
    picks = pick_types(raw.info, meg='mag', stim=False, ecg=False,
                       eog=False, exclude='bads')
    picks = picks[0:2]
    decim = 30

    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                        baseline=(None, 0), preload=True, decim=decim)
    # Test default running
    gat = GeneralizationAcrossTime()
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
                 "prediction, no score>", '%s' % gat)
    gat.predict(epochs)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predict_type : 'predict' on 15 epochs, no score>",
                 "%s" % gat)
    gat.score(epochs)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predict_type : 'predict' on 15 epochs,\n scored "
                 "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_type = gat.predict_type
    gat.predict_type = 'foo'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_type = old_type

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.047 (s), length: 0.047 (s), n_time_windows: 15>",
                 "%s" % gat.train_times)
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.047 (s), length: 0.047 (s), n_time_windows: 15 x 15>",
                 "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    assert_raises(ValueError, gat.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] ==
                gat.y_true_.shape[0] ==
                gat.y_pred_.shape[2] == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(len(gat.train_times['slices']) == 15 ==
                np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(len(gat.test_times_['slices']) == 15 ==
                np.shape(gat.scores_)[0])
    assert_true(len(gat.test_times_['slices'][0]) == 15 ==
                np.shape(gat.scores_)[1])

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    scores = gat.score(epochs)
    assert_true(isinstance(scores, list))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check

    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.score(epochs)
    assert_equal(len(gat.scores_), 8)

    # Test start stop training
    gat = GeneralizationAcrossTime(train_times={'start': 0.090,
                                                'stop': 0.250})
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times['times_'][0], epochs.times[6])
    assert_equal(gat.train_times['times_'][-1], epochs.times[9])

    # Test score without passing epochs
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    assert_raises(RuntimeError, gat.score)
    gat.predict(epochs, test_times='diagonal')  # Test diagonal decoding
    scores = gat.score()
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))

    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    gat.predict(epochs[7:])
    assert_raises(ValueError, gat.predict, epochs, test_times='hahahaha')
    assert_raises(RuntimeError, gat.score)
    gat.score(epochs[7:])

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc, predict_type='predict_proba',
                                   predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    assert_raises(ValueError, gat.score, epochs2)
    gat.score(epochs)
    scores = sum(scores, [])  # flatten
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # test various predict_type
    gat = GeneralizationAcrossTime(clf=svc, predict_type="predict_proba")
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    # check that 2 class probabilistic estimates are [p, 1-p]
    assert_true(gat.y_pred_.shape[3] == 2)
    gat.score(epochs)
    # check that continuous prediction leads to AUC rather than accuracy
    assert_true("roc_auc_score" in '%s' % gat.scorer_)

    gat = GeneralizationAcrossTime(predict_type="decision_function")
    # XXX Sklearn doesn't like non-binary inputs. We could binarize the data,
    # or change Sklearn default behavior
    epochs.events[:, 2][epochs.events[:, 2] == 3] = 0
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    # check that 2 class non-probabilistic continuous estimates are [distance]
    assert_true(gat.y_pred_.shape[3] == 1)
    gat.score(epochs)
    # check that continuous prediction leads to AUC rather than accuracy
    assert_true("roc_auc_score" in '%s' % gat.scorer_)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    assert_raises(ValueError, gat.predict, epochs[:10])

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2]  # 4 tested
    # nicely ordered labels or not
    y = epochs.events[:, 2]
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Classifier and regressor
    svc = SVC(C=1, kernel='linear', probability=True)
    clfs = [svc]  # SVR tested
    # Continuous, and probabilistic estimate
    predict_types = ['predict_proba', 'decision_function']
    # Test all combinations
    for clf_n, clf in enumerate(clfs):
        for y in ys:
            for n_class in n_classes:
                for pt in predict_types:
                    y_ = y % n_class
                    with warnings.catch_warnings(record=True):
                        gat = GeneralizationAcrossTime(
                            cv=2, clf=clf, predict_type=pt)
                        gat.fit(epochs, y=y_)
                        gat.score(epochs, y=y_)
###############################################################################
# Generalization Across Time
# --------------------------
#
# This runs the analysis used in [1]_ and further detailed in [2]_
#
# Here we'll use a stratified cross-validation scheme.

# make response vector
y = np.zeros(len(epochs.events), dtype=int)
y[epochs.events[:, 2] == 3] = 1
cv = StratifiedKFold(y=y)  # do a stratified cross-validation

# define the GeneralizationAcrossTime object
gat = GeneralizationAcrossTime(predict_mode="cross-validation", n_jobs=1, cv=cv, scorer=roc_auc_score)

# fit and score
gat.fit(epochs, y=y)
gat.score(epochs)

# let's visualize now
gat.plot()
gat.plot_diagonal()

###############################################################################
# Exercise
# --------
#  - Can you improve the performance using full epochs and a common spatial
#    pattern (CSP) used by most BCI systems?
#  - Explore other datasets from MNE (e.g. Face dataset from SPM to predict
示例#24
0
mne.equalize_channels([epochs_classic, epochs_plan])
mne.epochs.equalize_epoch_counts([epochs_classic, epochs_plan])

# Dirty hack # TODO: Check this from the Maxfilter side
# epochs_classic.info['dev_head_t'] = epochs_plan.info['dev_head_t']

epochs = mne.concatenate_epochs([epochs_classic, epochs_plan])

# Crop and downsmample to make it faster
epochs.crop(tmin=-3.5, tmax=0)
epochs.resample(250)

# Setup the y vector and GAT
y = np.concatenate(
    (np.zeros(len(epochs["press"])), np.ones(len(epochs["plan"]))))
gat = GeneralizationAcrossTime(
    predict_mode='mean-prediction', scorer="roc_auc", n_jobs=1)

# Fit model

# Scoring and visualise result
gat.score(epochs, y=y)

# Save model
joblib.dump(gat, data_path + "decode_time_gen/%s_gat_2.jl" % subject)

fig = gat.plot(
    title="Temporal Gen (Classic vs planning): left to right sub: %s" %
    subject)
fig.savefig(data_path + "decode_time_gen/%s_gat_matrix_2.png" % subject)
示例#25
0
	# decoding
	epochs = epochs.decimate(decim)
	n_tr = len(epochs.times)
	X = epochs[stim_list>0]
	y = stim_list[stim_list>0]

	# SVM parameters
	scaler = StandardScaler() # centers data by removing the mean and scales to unit variance
	# model = svm.SVC(C=1, kernel='linear', class_weight='auto')
	model = svm.LinearSVC(C=1, multi_class='ovr', class_weight='auto')
	clf = make_pipeline(scaler, model)
	cv = StratifiedKFold(y, n_fold)
	gat = GeneralizationAcrossTime(
		cv=cv,
		clf=clf, 
		predict_mode='cross-validation', 
		n_jobs=n_jobs,
		# train_times=dict(step=step,	length=length)
		)

	gat.fit(X, y)
	# score = gat.score(X, y)
	# gat.plot(vmin=.2, vmax=.3)
	# gat.plot_diagonal(chance=.25)

	#######################################################################################################
	 # now for the rsvp data 
	fname = op.join(data_path, 'abse_' + subject + '_main.mat')

	epochs = sm_fieldtrip2mne(fname)
	n_trial = len(epochs)
示例#26
0
evokeds = {key:epochs[key].average() for key in event_id.keys()}

np468 = mne.combine_evoked([evokeds['np_4'],evokeds['np_6'],evokeds['np_8']], weights='equal')
f1 = np468.plot_joint([.18,.3,.45,.6],title='Non Pop')
axes = f1.get_axes()
axes[0].set_ylim([-110, 110])


p468 = mne.combine_evoked([evokeds['p_4'],evokeds['p_6'],evokeds['p_8']], weights='equal')
f2 = p468.plot_joint([.18,.3,.45,.6],title='Pop')
axes = f2.get_axes()
axes[0].set_ylim([-110, 110])


triggers = epochs.events[:, 2]
gat = GeneralizationAcrossTime(predict_mode='cross-validation', n_jobs=12)
#gat = GeneralizationAcrossTime(predict_mode='mean-prediction', n_jobs=12)


ind = np.in1d(triggers, (4, 5, 6)).astype(int)
gat.fit(epochs[('np_4', 'np_6', 'np_8' ,'p_4', 'p_6', 'p_8')], y=ind)
gat.score(epochs[('np_4', 'np_6', 'np_8' ,'p_4', 'p_6', 'p_8')], y=ind)
gat.plot(vmin=.55,vmax=.7)
gat.plot_diagonal()


###
np8_vs_p4 = (triggers[np.in1d(triggers, (3, 4))] == 4).astype(int)
p8_vs_np4 = (triggers[np.in1d(triggers, (6, 1))] == 1).astype(int)
p8_vs_np8 = (triggers[np.in1d(triggers, (6, 3))] == 3).astype(int)
p6_vs_np6 = (triggers[np.in1d(triggers, (5, 2))] == 2).astype(int)
示例#27
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC
    from sklearn.linear_model import RANSACRegressor, LinearRegression
    from sklearn.preprocessing import LabelEncoder
    from sklearn.metrics import mean_squared_error
    from sklearn.cross_validation import LeaveOneLabelOut

    epochs = make_epochs()

    # Test default running
    gat = GeneralizationAcrossTime(picks='foo')
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    assert_raises(ValueError, gat.fit, epochs)
    with warnings.catch_warnings(record=True):
        # check classic fit + check manual picks
        gat.picks = [0]
        gat.fit(epochs)
        # check optional y as array
        gat.picks = None
        gat.fit(epochs, y=epochs.events[:, 2])
        # check optional y as list
        gat.fit(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(len(gat.picks_), len(gat.ch_names), 1)
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
        "prediction, no score>", '%s' % gat)
    assert_equal(gat.ch_names, epochs.ch_names)
    gat.predict(epochs)
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
        "predicted 14 epochs, no score>", "%s" % gat)
    gat.score(epochs)
    gat.score(epochs, y=epochs.events[:, 2])
    gat.score(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
        "predicted 14 epochs,\n scored "
        "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal(
        "<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
        "0.047 (s), length: 0.047 (s), n_time_windows: 15>",
        "%s" % gat.train_times_)
    assert_equal(
        "<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
        "0.047 (s), length: 0.047 (s), n_time_windows: 15 x 15>",
        "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    gat_ = copy.deepcopy(gat)
    assert_raises(ValueError, gat_.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] == gat.y_true_.shape[0] == len(
        gat.y_pred_[0][0]) == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(
        len(gat.train_times_['slices']) == 15 == np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(
        len(gat.test_times_['slices']) == 15 == np.shape(gat.scores_)[0])
    assert_true(
        len(gat.test_times_['slices'][0]) == 15 == np.shape(gat.scores_)[1])

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    scores = gat.score(epochs)
    assert_true(isinstance(scores, list))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check

    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.score(epochs)
    assert_true(len(gat.scores_) == len(gat.estimators_) == 8)  # training time
    assert_equal(len(gat.scores_[0]), 15)  # testing time

    # Test start stop training & test cv without n_fold params
    y_4classes = np.hstack((epochs.events[:7, 2], epochs.events[7:, 2] + 1))
    gat = GeneralizationAcrossTime(cv=LeaveOneLabelOut(y_4classes),
                                   train_times={
                                       'start': 0.090,
                                       'stop': 0.250
                                   })
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=y_4classes)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times_['times'][0], epochs.times[6])
    assert_equal(gat.train_times_['times'][-1], epochs.times[9])

    # Test score without passing epochs & Test diagonal decoding
    gat = GeneralizationAcrossTime(test_times='diagonal')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    assert_raises(RuntimeError, gat.score)
    gat.predict(epochs)
    scores = gat.score()
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))
    assert_array_equal(
        [tim for ttime in gat.test_times_['times'] for tim in ttime],
        gat.train_times_['times'])

    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    gat.predict(epochs[7:])
    gat.score(epochs[7:])

    # Test training time parameters
    gat_ = copy.deepcopy(gat)
    # --- start stop outside time range
    gat_.train_times = dict(start=-999.)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(start=999.)
    assert_raises(ValueError, gat_.fit, epochs)
    # --- impossible slices
    gat_.train_times = dict(step=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=999.)
    assert_raises(ValueError, gat_.fit, epochs)

    # Test testing time parameters
    # --- outside time range
    gat.test_times = dict(start=-999.)
    assert_raises(ValueError, gat.predict, epochs)
    gat.test_times = dict(start=999.)
    assert_raises(ValueError, gat.predict, epochs)
    # --- impossible slices
    gat.test_times = dict(step=.000001)
    assert_raises(ValueError, gat.predict, epochs)
    gat_ = copy.deepcopy(gat)
    gat_.train_times_['length'] = .000001
    gat_.test_times = dict(length=.000001)
    assert_raises(ValueError, gat_.predict, epochs)
    # --- test time region of interest
    gat.test_times = dict(step=.150)
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 5, 14, 1))
    # --- silly value
    gat.test_times = 'foo'
    assert_raises(ValueError, gat.predict, epochs)
    assert_raises(RuntimeError, gat.score)
    # --- unmatched length between training and testing time
    gat.test_times = dict(length=.150)
    assert_raises(ValueError, gat.predict, epochs)

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc, predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    assert_raises(ValueError, gat.score, epochs2)
    gat.score(epochs)
    scores = sum(scores, [])  # flatten
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    assert_raises(ValueError, gat.predict, epochs[:10])

    # Check that still works with classifier that output y_pred with
    # shape = (n_trials, 1) instead of (n_trials,)
    gat = GeneralizationAcrossTime(clf=RANSACRegressor(LinearRegression()),
                                   cv=2)
    epochs.crop(None, epochs.times[2])
    gat.fit(epochs)
    gat.predict(epochs)

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2, 4]  # 4 tested
    # nicely ordered labels or not
    le = LabelEncoder()
    y = le.fit_transform(epochs.events[:, 2])
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Univariate and multivariate prediction
    svc = SVC(C=1, kernel='linear')

    class SVC_proba(SVC):
        def predict(self, x):
            probas = super(SVC_proba, self).predict_proba(x)
            return probas[:, 0]

    svcp = SVC_proba(C=1, kernel='linear', probability=True)
    clfs = [svc, svcp]
    scorers = [None, mean_squared_error]
    # Test all combinations
    for clf, scorer in zip(clfs, scorers):
        for y in ys:
            for n_class in n_classes:
                y_ = y % n_class
                with warnings.catch_warnings(record=True):
                    gat = GeneralizationAcrossTime(cv=2,
                                                   clf=clf,
                                                   scorer=scorer)
                    gat.fit(epochs, y=y_)
                    gat.score(epochs, y=y_)
示例#28
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC
    from sklearn.base import is_classifier
    # KernelRidge is used for testing 1) regression analyses 2) n-dimensional
    # predictions.
    from sklearn.kernel_ridge import KernelRidge
    from sklearn.preprocessing import LabelEncoder
    from sklearn.metrics import roc_auc_score, mean_squared_error

    epochs = make_epochs()
    y_4classes = np.hstack((epochs.events[:7, 2], epochs.events[7:, 2] + 1))
    if check_version('sklearn', '0.18'):
        from sklearn.model_selection import (KFold, StratifiedKFold,
                                             ShuffleSplit, LeaveOneLabelOut)
        cv_shuffle = ShuffleSplit()
        cv = LeaveOneLabelOut()
        # XXX we cannot pass any other parameters than X and y to cv.split
        # so we have to build it before hand
        cv_lolo = [(train, test) for train, test in cv.split(
                   X=y_4classes, y=y_4classes, labels=y_4classes)]

        # With sklearn >= 0.17, `clf` can be identified as a regressor, and
        # the scoring metrics can therefore be automatically assigned.
        scorer_regress = None
    else:
        from sklearn.cross_validation import (KFold, StratifiedKFold,
                                              ShuffleSplit, LeaveOneLabelOut)
        cv_shuffle = ShuffleSplit(len(epochs))
        cv_lolo = LeaveOneLabelOut(y_4classes)

        # With sklearn < 0.17, `clf` cannot be identified as a regressor, and
        # therefore the scoring metrics cannot be automatically assigned.
        scorer_regress = mean_squared_error
    # Test default running
    gat = GeneralizationAcrossTime(picks='foo')
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    assert_raises(ValueError, gat.fit, epochs)
    with warnings.catch_warnings(record=True):
        # check classic fit + check manual picks
        gat.picks = [0]
        gat.fit(epochs)
        # check optional y as array
        gat.picks = None
        gat.fit(epochs, y=epochs.events[:, 2])
        # check optional y as list
        gat.fit(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(len(gat.picks_), len(gat.ch_names), 1)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
                 "prediction, no score>", '%s' % gat)
    assert_equal(gat.ch_names, epochs.ch_names)
    # test different predict function:
    gat = GeneralizationAcrossTime(predict_method='decision_function')
    gat.fit(epochs)
    # With classifier, the default cv is StratifiedKFold
    assert_true(gat.cv_.__class__ == StratifiedKFold)
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 15, 14, 1))
    gat.predict_method = 'predict_proba'
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 15, 14, 2))
    gat.predict_method = 'foo'
    assert_raises(NotImplementedError, gat.predict, epochs)
    gat.predict_method = 'predict'
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 15, 14, 1))
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predicted 14 epochs, no score>",
                 "%s" % gat)
    gat.score(epochs)
    assert_true(gat.scorer_.__name__ == 'accuracy_score')
    # check clf / predict_method combinations for which the scoring metrics
    # cannot be inferred.
    gat.scorer = None
    gat.predict_method = 'decision_function'
    assert_raises(ValueError, gat.score, epochs)
    # Check specifying y manually
    gat.predict_method = 'predict'
    gat.score(epochs, y=epochs.events[:, 2])
    gat.score(epochs, y=epochs.events[:, 2].tolist())
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predicted 14 epochs,\n scored "
                 "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.050 (s), length: 0.050 (s), n_time_windows: 15>",
                 "%s" % gat.train_times_)
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.050 (s), length: 0.050 (s), n_time_windows: 15 x 15>",
                 "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    gat_ = copy.deepcopy(gat)
    with use_log_level('error'):
        assert_raises(ValueError, gat_.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] ==
                gat.y_true_.shape[0] ==
                len(gat.y_pred_[0][0]) == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(len(gat.train_times_['slices']) == 15 ==
                np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(len(gat.test_times_['slices']) == 15 ==
                np.shape(gat.scores_)[0])
    assert_true(len(gat.test_times_['slices'][0]) == 15 ==
                np.shape(gat.scores_)[1])

    # Test score_mode
    gat.score_mode = 'foo'
    assert_raises(ValueError, gat.score, epochs)
    gat.score_mode = 'fold-wise'
    scores = gat.score(epochs)
    assert_array_equal(np.shape(scores), [15, 15, 5])
    gat.score_mode = 'mean-sample-wise'
    scores = gat.score(epochs)
    assert_array_equal(np.shape(scores), [15, 15])
    gat.score_mode = 'mean-fold-wise'
    scores = gat.score(epochs)
    assert_array_equal(np.shape(scores), [15, 15])
    gat.predict_mode = 'mean-prediction'
    with warnings.catch_warnings(record=True) as w:
        gat.score(epochs)
        assert_true(any("score_mode changed from " in str(ww.message)
                        for ww in w))

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    with warnings.catch_warnings(record=True):  # not vectorizing
        scores = gat.score(epochs)
    assert_true(isinstance(scores, np.ndarray))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check
    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.score(epochs)
    assert_true(len(gat.scores_) == len(gat.estimators_) == 8)  # training time
    assert_equal(len(gat.scores_[0]), 15)  # testing time

    # Test start stop training & test cv without n_fold params
    y_4classes = np.hstack((epochs.events[:7, 2], epochs.events[7:, 2] + 1))
    train_times = dict(start=0.090, stop=0.250)
    gat = GeneralizationAcrossTime(cv=cv_lolo, train_times=train_times)
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=y_4classes)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times_['times'][0], epochs.times[6])
    assert_equal(gat.train_times_['times'][-1], epochs.times[9])

    # Test score without passing epochs & Test diagonal decoding
    gat = GeneralizationAcrossTime(test_times='diagonal')
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.fit(epochs)
    assert_raises(RuntimeError, gat.score)
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.predict(epochs)
    scores = gat.score()
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))
    assert_array_equal([tim for ttime in gat.test_times_['times']
                        for tim in ttime], gat.train_times_['times'])
    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction', cv=2)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    with warnings.catch_warnings(record=True):
        # There are some empty test folds because of n_trials
        gat.predict(epochs[7:])
        gat.score(epochs[7:])

    # Test training time parameters
    gat_ = copy.deepcopy(gat)
    # --- start stop outside time range
    gat_.train_times = dict(start=-999.)
    with use_log_level('error'):
        assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(start=999.)
    assert_raises(ValueError, gat_.fit, epochs)
    # --- impossible slices
    gat_.train_times = dict(step=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=999.)
    assert_raises(ValueError, gat_.fit, epochs)

    # Test testing time parameters
    # --- outside time range
    gat.test_times = dict(start=-999.)
    with warnings.catch_warnings(record=True):  # no epochs in fold
        assert_raises(ValueError, gat.predict, epochs)
    gat.test_times = dict(start=999.)
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat.predict, epochs)
    # --- impossible slices
    gat.test_times = dict(step=.000001)
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat.predict, epochs)
    gat_ = copy.deepcopy(gat)
    gat_.train_times_['length'] = .000001
    gat_.test_times = dict(length=.000001)
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat_.predict, epochs)
    # --- test time region of interest
    gat.test_times = dict(step=.150)
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 5, 14, 1))
    # --- silly value
    gat.test_times = 'foo'
    with warnings.catch_warnings(record=True):  # no test epochs
        assert_raises(ValueError, gat.predict, epochs)
    assert_raises(RuntimeError, gat.score)
    # --- unmatched length between training and testing time
    gat.test_times = dict(length=.150)
    assert_raises(ValueError, gat.predict, epochs)
    # --- irregular length training and testing times
    # 2 estimators, the first one is trained on two successive time samples
    # whereas the second one is trained on a single time sample.
    train_times = dict(slices=[[0, 1], [1]])
    # The first estimator is tested once, the second estimator is tested on
    # two successive time samples.
    test_times = dict(slices=[[[0, 1]], [[0], [1]]])
    gat = GeneralizationAcrossTime(train_times=train_times,
                                   test_times=test_times)
    gat.fit(epochs)
    with warnings.catch_warnings(record=True):  # not vectorizing
        gat.score(epochs)
    assert_array_equal(np.shape(gat.y_pred_[0]), [1, len(epochs), 1])
    assert_array_equal(np.shape(gat.y_pred_[1]), [2, len(epochs), 1])
    # check cannot Automatically infer testing times for adhoc training times
    gat.test_times = None
    assert_raises(ValueError, gat.predict, epochs)

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc, predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    with use_log_level('error'):
        assert_raises(ValueError, gat.score, epochs2)
        gat.score(epochs)
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime(cv=cv_shuffle)
    gat.fit(epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.predict(epochs)
    assert_raises(ValueError, gat.predict, epochs[:10])

    # Make CV with some empty train and test folds:
    # --- empty test fold(s) should warn when gat.predict()
    gat._cv_splits[0] = [gat._cv_splits[0][0], np.empty(0)]
    with warnings.catch_warnings(record=True) as w:
        gat.predict(epochs)
        assert_true(len(w) > 0)
        assert_true(any('do not have any test epochs' in str(ww.message)
                        for ww in w))
    # --- empty train fold(s) should raise when gat.fit()
    gat = GeneralizationAcrossTime(cv=[([0], [1]), ([], [0])])
    assert_raises(ValueError, gat.fit, epochs[:2])

    # Check that still works with classifier that output y_pred with
    # shape = (n_trials, 1) instead of (n_trials,)
    if check_version('sklearn', '0.17'):  # no is_regressor before v0.17
        gat = GeneralizationAcrossTime(clf=KernelRidge(), cv=2)
        epochs.crop(None, epochs.times[2])
        gat.fit(epochs)
        # With regression the default cv is KFold and not StratifiedKFold
        assert_true(gat.cv_.__class__ == KFold)
        gat.score(epochs)
        # with regression the default scoring metrics is mean squared error
        assert_true(gat.scorer_.__name__ == 'mean_squared_error')

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2, 4]  # 4 tested
    # nicely ordered labels or not
    le = LabelEncoder()
    y = le.fit_transform(epochs.events[:, 2])
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Univariate and multivariate prediction
    svc = SVC(C=1, kernel='linear', probability=True)
    reg = KernelRidge()

    def scorer_proba(y_true, y_pred):
        return roc_auc_score(y_true, y_pred[:, 0])

    # We re testing 3 scenario: default, classifier + predict_proba, regressor
    scorers = [None, scorer_proba, scorer_regress]
    predict_methods = [None, 'predict_proba', None]
    clfs = [svc, svc, reg]
    # Test all combinations
    for clf, predict_method, scorer in zip(clfs, predict_methods, scorers):
        for y in ys:
            for n_class in n_classes:
                for predict_mode in ['cross-validation', 'mean-prediction']:
                    # Cannot use AUC for n_class > 2
                    if (predict_method == 'predict_proba' and n_class != 2):
                        continue

                    y_ = y % n_class

                    with warnings.catch_warnings(record=True):
                        gat = GeneralizationAcrossTime(
                            cv=2, clf=clf, scorer=scorer,
                            predict_mode=predict_mode)
                        gat.fit(epochs, y=y_)
                        gat.score(epochs, y=y_)

                    # Check that scorer is correctly defined manually and
                    # automatically.
                    scorer_name = gat.scorer_.__name__
                    if scorer is None:
                        if is_classifier(clf):
                            assert_equal(scorer_name, 'accuracy_score')
                        else:
                            assert_equal(scorer_name, 'mean_squared_error')
                    else:
                        assert_equal(scorer_name, scorer.__name__)
    # decimate data
    decim = 2
    epochs.decimate(decim)
    # only keep data > 0 ms & < 400 ms
    epochs.crop(-.100, .750)

    ######################################################################
    # Decoding
    # set up a classifier based on a regularized Logistic Regression
    clf = LogisticRegression(C=1)
    # force the classifer to output a probabilistic prediction
    clf = force_predict(clf, axis=1)
    # insert a z-score normalization step before the classification
    clf = make_pipeline(StandardScaler(), clf)
    # initialize the GAT object
    gat = GeneralizationAcrossTime(clf=clf, scorer=scorer_auc, n_jobs=-1,
                                   cv=10)

    # select the trials where a target is presented
    for contrast in ['HL', 'EU', 'PR']:
        epochs_ = concatenate_epochs((epochs[contrast[0]],
                                      epochs[contrast[1]]))
        y = np.hstack((np.zeros(len(epochs[contrast[0]])),
                       np.ones(len(epochs[contrast[1]]))))
        gat.fit(epochs_, y=y)
        fname = op.join(data_path, 's%i_%s_fit.pkl' % (subject, contrast))
        with open(fname, 'wb') as f:
            pickle.dump(gat, f)
        # TODO: should save y_pred separately

        # predict + score
        scores = gat.score(epochs_, y=y)

# RUN GAT
angle2circle = lambda angles: np.deg2rad(2 * (angles + 7.5))
circle2angle = lambda angles: np.rad2deg(2 * angles) / 2 - 7.5

cos = lambda angles: np.cos(angle2circle(angles))
sin = lambda angles: np.sin(angle2circle(angles))

scaler = StandardScaler()
svr = SVR(C=1, kernel='linear')
clf = Pipeline([('scaler', scaler), ('svr', svr)])

gats = list()
for transform in [cos, sin]:
    gat = GeneralizationAcrossTime(n_jobs=1, clf=clf)
    gat.fit(epochs, y=transform(trial_angles))
    gat.score(epochs, y=transform(trial_angles))
    gats.append(gat)


# ALIGN ANGLES
cart2pol = lambda x, y: np.arctan2(y, x)
pi = np.pi

gatx = gats[0]
gaty = gats[1]

# get true angle
true_x = gatx.y_train_
true_y = gaty.y_train_
                    sel = np.where(sel)[0]

                    # reduce number or trials if too many XXX just for speed, remove
                    if len(sel) > 400:
                        import random
                        random.shuffle(sel)
                        sel = sel[0:400]

                    y = np.array(events[cond_name].tolist())

                    # Apply contrast
                    if clf_type['name']=='SVC':
                        decoding_parameters = decoding_params[0]['values']
                    elif clf_type['name']=='SVR':
                        decoding_parameters = decoding_params[1]['values']
                    gat = GeneralizationAcrossTime(**decoding_parameters)
                    gat.fit(epochs[sel], y=y[sel])
                    gat.score(epochs[sel], y=y[sel])

                    # Plot
                    fig = gat.plot_diagonal(show=False)
                    report.add_figs_to_section(fig,
                        ('%s %s: (decoding)' % (subject, cond_name)), subject)

                    fig = gat.plot(show=False)
                    report.add_figs_to_section(fig,
                        ('%s %s: GAT' % (subject, cond_name)), subject)

                    # Save contrast
                    pkl_fname = op.join(data_path, subject, 'mvpas',
                        '{}-decod_{}_{}{}.pickle'.format(subject, cond_name,clf_type['name'],fname_appendix))
        lbl = LabelEncoder()
        y = lbl.fit_transform(epochs.events[:, -1])

        print 'get ready for decoding ;)'

        # Generalization Across Time
        # default GAT: LogisticRegression with KFold (n=5)
        train_times = {
            'start': tmin,
            'stop': tmax,
            'length': length,
            'step': step
        }
        gat = GeneralizationAcrossTime(predict_mode='cross-validation',
                                       n_jobs=1,
                                       train_times=train_times,
                                       clf=clf,
                                       cv=n_folds)
        gat.fit(epochs, y=y)
        gat.score(epochs, y=y)
        np.save(fname_gat, gat.scores_)

        # store weights
        weights = list()
        for fold in range(n_folds):
            # weights explained: gat.estimator_[time_point][fold].steps[-1][-1].coef_
            weights.append(
                np.vstack([
                    gat.estimators_[idx][fold].steps[-1][-1].coef_
                    for idx in range(len(epochs.times))
                ]))
decim = 2  # decimate to make the example faster to run
epochs = mne.Epochs(raw, events, event_id, -0.050, 0.400, proj=True,
                    picks=picks, baseline=None, preload=True,
                    reject=dict(mag=5e-12), decim=decim, verbose=False)

# We will train the classifier on all left visual vs auditory trials
# and test on all right visual vs auditory trials.

# In this case, because the test data is independent from the train data,
# we test the classifier of each fold and average the respective predictions.

# Define events of interest
triggers = epochs.events[:, 2]
viz_vs_auditory = np.in1d(triggers, (1, 2)).astype(int)

gat = GeneralizationAcrossTime(predict_mode='mean-prediction', n_jobs=1)

# For our left events, which ones are visual?
viz_vs_auditory_l = (triggers[np.in1d(triggers, (1, 3))] == 3).astype(int)
# To make scikit-learn happy, we converted the bool array to integers
# in the same line. This results in an array of zeros and ones:
print("The unique classes' labels are: %s" % np.unique(viz_vs_auditory_l))

gat.fit(epochs[('AudL', 'VisL')], y=viz_vs_auditory_l)

# For our right events, which ones are visual?
viz_vs_auditory_r = (triggers[np.in1d(triggers, (2, 4))] == 4).astype(int)

gat.score(epochs[('AudR', 'VisR')], y=viz_vs_auditory_r)
gat.plot(
    title="Generalization Across Time (visual vs auditory): left to right")
示例#34
0
cv = StratifiedKFold(n_splits=10, shuffle=True)

# Create epochs to use for classification
n_trial, n_chan, n_time = X.shape
events = np.vstack((range(n_trial), np.zeros(n_trial, int), y.astype(int))).T
chan_names = ['MEG %i' % chan for chan in range(n_chan)]
chan_types = ['mag'] * n_chan
sfreq = 250
info = create_info(chan_names, sfreq, chan_types)
epochs = EpochsArray(data=X, info=info, events=events, verbose=False)
epochs.times = selected_times[:n_time]

epochs.crop(-3.8, None)

# fit model and score
gat = GeneralizationAcrossTime(
    scorer="accuracy", cv=cv, predict_method="predict")
gat.fit(epochs, y=y)
gat.score(epochs, y=y)

# Save model
joblib.dump(gat, data_path + "decode_time_gen/%s_gat_tr.jl" % subject)

# make matrix plot and save it
fig = gat.plot(
    cmap="viridis",
    title="Temporal Gen (Classic vs planning) for transitivity.")
fig.savefig(data_path + "decode_time_gen/%s_gat_matrix_tr.png" % subject)

fig = gat.plot_diagonal(
    chance=0.5, title="Temporal Gen (Classic vs planning) for transitivity")
fig.savefig(data_path + "decode_time_gen/%s_gat_diagonal_tr.png" % subject)
示例#35
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC
    from sklearn.linear_model import RANSACRegressor, LinearRegression
    from sklearn.preprocessing import LabelEncoder
    from sklearn.metrics import mean_squared_error
    from sklearn.cross_validation import LeaveOneLabelOut

    epochs = make_epochs()

    # Test default running
    gat = GeneralizationAcrossTime(picks='foo')
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    assert_raises(ValueError, gat.fit, epochs)
    with warnings.catch_warnings(record=True):
        # check classic fit + check manual picks
        gat.picks = [0]
        gat.fit(epochs)
        # check optional y as array
        gat.picks = None
        gat.fit(epochs, y=epochs.events[:, 2])
        # check optional y as list
        gat.fit(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(len(gat.picks_), len(gat.ch_names), 1)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
                 "prediction, no score>", '%s' % gat)
    assert_equal(gat.ch_names, epochs.ch_names)
    gat.predict(epochs)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predicted 14 epochs, no score>",
                 "%s" % gat)
    gat.score(epochs)
    gat.score(epochs, y=epochs.events[:, 2])
    gat.score(epochs, y=epochs.events[:, 2].tolist())
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predicted 14 epochs,\n scored "
                 "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.050 (s), length: 0.050 (s), n_time_windows: 15>",
                 "%s" % gat.train_times_)
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.050 (s), length: 0.050 (s), n_time_windows: 15 x 15>",
                 "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    gat_ = copy.deepcopy(gat)
    assert_raises(ValueError, gat_.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] ==
                gat.y_true_.shape[0] ==
                len(gat.y_pred_[0][0]) == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(len(gat.train_times_['slices']) == 15 ==
                np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(len(gat.test_times_['slices']) == 15 ==
                np.shape(gat.scores_)[0])
    assert_true(len(gat.test_times_['slices'][0]) == 15 ==
                np.shape(gat.scores_)[1])

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    scores = gat.score(epochs)
    assert_true(isinstance(scores, list))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check

    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.score(epochs)
    assert_true(len(gat.scores_) == len(gat.estimators_) == 8)  # training time
    assert_equal(len(gat.scores_[0]), 15)  # testing time

    # Test start stop training & test cv without n_fold params
    y_4classes = np.hstack((epochs.events[:7, 2], epochs.events[7:, 2] + 1))
    gat = GeneralizationAcrossTime(cv=LeaveOneLabelOut(y_4classes),
                                   train_times={'start': 0.090, 'stop': 0.250})
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=y_4classes)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times_['times'][0], epochs.times[6])
    assert_equal(gat.train_times_['times'][-1], epochs.times[9])

    # Test score without passing epochs & Test diagonal decoding
    gat = GeneralizationAcrossTime(test_times='diagonal')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    assert_raises(RuntimeError, gat.score)
    gat.predict(epochs)
    scores = gat.score()
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))
    assert_array_equal([tim for ttime in gat.test_times_['times']
                        for tim in ttime], gat.train_times_['times'])

    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    gat.predict(epochs[7:])
    gat.score(epochs[7:])

    # Test training time parameters
    gat_ = copy.deepcopy(gat)
    # --- start stop outside time range
    gat_.train_times = dict(start=-999.)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(start=999.)
    assert_raises(ValueError, gat_.fit, epochs)
    # --- impossible slices
    gat_.train_times = dict(step=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=.000001)
    assert_raises(ValueError, gat_.fit, epochs)
    gat_.train_times = dict(length=999.)
    assert_raises(ValueError, gat_.fit, epochs)

    # Test testing time parameters
    # --- outside time range
    gat.test_times = dict(start=-999.)
    assert_raises(ValueError, gat.predict, epochs)
    gat.test_times = dict(start=999.)
    assert_raises(ValueError, gat.predict, epochs)
    # --- impossible slices
    gat.test_times = dict(step=.000001)
    assert_raises(ValueError, gat.predict, epochs)
    gat_ = copy.deepcopy(gat)
    gat_.train_times_['length'] = .000001
    gat_.test_times = dict(length=.000001)
    assert_raises(ValueError, gat_.predict, epochs)
    # --- test time region of interest
    gat.test_times = dict(step=.150)
    gat.predict(epochs)
    assert_array_equal(np.shape(gat.y_pred_), (15, 5, 14, 1))
    # --- silly value
    gat.test_times = 'foo'
    assert_raises(ValueError, gat.predict, epochs)
    assert_raises(RuntimeError, gat.score)
    # --- unmatched length between training and testing time
    gat.test_times = dict(length=.150)
    assert_raises(ValueError, gat.predict, epochs)

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc, predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    assert_raises(ValueError, gat.score, epochs2)
    gat.score(epochs)
    scores = sum(scores, [])  # flatten
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.predict(epochs)
    assert_raises(IndexError, gat.predict, epochs[:10])

    # TODO JRK: test GAT with non-exhaustive CV (eg. train on 80%, test on 10%)

    # Check that still works with classifier that output y_pred with
    # shape = (n_trials, 1) instead of (n_trials,)
    gat = GeneralizationAcrossTime(clf=RANSACRegressor(LinearRegression()),
                                   cv=2)
    epochs.crop(None, epochs.times[2])
    gat.fit(epochs)
    gat.predict(epochs)

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2, 4]  # 4 tested
    # nicely ordered labels or not
    le = LabelEncoder()
    y = le.fit_transform(epochs.events[:, 2])
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Univariate and multivariate prediction
    svc = SVC(C=1, kernel='linear')

    class SVC_proba(SVC):
        def predict(self, x):
            probas = super(SVC_proba, self).predict_proba(x)
            return probas[:, 0]

    svcp = SVC_proba(C=1, kernel='linear', probability=True)
    clfs = [svc, svcp]
    scorers = [None, mean_squared_error]
    # Test all combinations
    for clf, scorer in zip(clfs, scorers):
        for y in ys:
            for n_class in n_classes:
                y_ = y % n_class
                with warnings.catch_warnings(record=True):
                    gat = GeneralizationAcrossTime(cv=2, clf=clf,
                                                   scorer=scorer)
                    gat.fit(epochs, y=y_)
                    gat.score(epochs, y=y_)
print(__doc__)

# Preprocess data
data_path = spm_face.data_path()
# Load and filter data, set up epochs
raw_fname = data_path + '/MEG/spm/SPM_CTF_MEG_example_faces%d_3D_raw.fif'

raw = mne.io.Raw(raw_fname % 1, preload=True)  # Take first run

picks = mne.pick_types(raw.info, meg=True, exclude='bads')
raw.filter(1, 45, method='iir')

events = mne.find_events(raw, stim_channel='UPPT001')
event_id = {"faces": 1, "scrambled": 2}
tmin, tmax = -0.1, 0.5

decim = 4  # decimate to make the example faster to run
epochs = mne.Epochs(raw, events, event_id, tmin, tmax, proj=True,
                    picks=picks, baseline=None, preload=True,
                    reject=dict(mag=1.5e-12), decim=decim, verbose=False)

# Define decoder. The decision function is employed to use cross-validation
gat = GeneralizationAcrossTime(predict_mode='cross-validation', n_jobs=1)

# fit and score
gat.fit(epochs)
gat.score(epochs)
gat.plot(vmin=0.1, vmax=0.9,
         title="Generalization Across Time (faces vs. scrambled)")
gat.plot_diagonal()  # plot decoding across time (correspond to GAT diagonal)
epochs_clt_left.events[:, 2] = 0
epochs_clt_right.events[:, 2] = 1

epochs_clt_left.event_id = {"0": 0}
epochs_clt_right.event_id = {"1": 1}

epochs_data = mne.concatenate_epochs([epochs_clt_left, epochs_clt_right])

# Equalise channels and epochs, and concatenate epochs
epochs_data.equalize_event_counts(["0", "1"])

# Classifier
clf = make_pipeline(StandardScaler(), LogisticRegression(C=1))

# Setup the y vector and GAT
gat = GeneralizationAcrossTime(
    predict_mode='mean-prediction', scorer="roc_auc", n_jobs=1)

# Fit model
print("fitting GAT")
gat.fit(epochs_data)

# Scoring
print("Scoring GAT")
gat.score(epochs_data)

# Save model
joblib.dump(
    gat, data_path + "decode_time_gen/%s_gat_allsensor-grad_ctl.jl" % subject)

# make matrix plot and save it
fig = gat.plot(cmap="viridis", title="Temporal Gen for subject: %s" % subject)
示例#38
0
def simulate_model(sources, mixin, background, snr=.5, n_trial=100):
    """Run simulations :
    1. Takes source activations in two visibility conditions:
        dict(high=(n_sources * n_times), low=(n_sources * n_times))
    2. Target presence/absence is coded in y vector and corresponds to the
       reverse activation in source space.
    3. Takes a mixin matrix that project the data from source space to sensor
        space
    4. Generates multiple low and high visibility trials.
    5. Fit target presence (y) across all trials (both high and low visiblity),
    6. Score target presence separately for high and low visibility trials
    7. Fit and score target visibility (for simplicity reasons, we only have 2
       visibility conditions. Consequently, we will fit a logistic regression
       and not a ridge like the one used for in empirical part of the paper.)
    """
    n_source, n_chan = mixin.shape

    # add information
    X, y, visibility = list(), list(), list()
    for vis, source in sources.iteritems():
        n_source, n_time = source.shape
        # define present and absent in source space
        present = np.stack([source + background] * (n_trial // 2))
        absent = np.stack([background] * (n_trial // 2))
        source = np.vstack((present, absent))
        y_ = np.hstack((np.ones(n_trial // 2), -1 * np.ones(n_trial // 2)))

        # transform in sensor space
        sensor = np.dot(mixin.T, np.hstack((source)))
        sensor = np.reshape(sensor, [n_chan, -1, n_time]).transpose(1, 0, 2)

        # add sensor specific  noise
        sensor += np.random.randn(n_trial, n_chan, n_time) / snr
        X.append(sensor)
        y.append(y_)
        visibility.append(int(vis == 'high') * np.ones(n_trial))
    X = np.concatenate(X, axis=0)
    y = np.concatenate(y, axis=0)
    visibility = np.concatenate(visibility, axis=0)

    # shuffle trials
    idx = range(n_trial * 2)
    np.random.shuffle(idx)
    X, y, visibility = X[idx], y[idx], visibility[idx]

    # format to MNE epochs
    epochs = EpochsArray(X, create_info(n_chan, sfreq, 'mag'), tmin=times[0],
                         proj=False, baseline=None)

    # Temporal generalization pipeline
    gat = GeneralizationAcrossTime(clf=analysis['clf'], cv=8,
                                   scorer=scorer_auc, n_jobs=-1,
                                   score_mode='mean-sample-wise')

    gat.fit(epochs, y=y)
    y_pred = gat.predict(epochs)
    y_pred = y_pred[:, :, :, 0].transpose(2, 0, 1)

    score = list()
    for vis in range(2):
        # select all absent trials + present at a given visibility
        sel = np.unique(np.hstack((np.where(y == -1)[0],
                        np.where(visibility == vis)[0])))
        score_ = scorer_auc(y[sel], y_pred[sel], n_jobs=-1)
        score.append(score_)

    # correlation with visibility
    sel = np.where(y == 1)[0]
    corr_vis = scorer_spearman(visibility[sel], y_pred[sel], n_jobs=-1)

    # decode visibility
    sel = np.where(y == 1)[0]  # present trials only
    gat.fit(epochs[sel], y=visibility[sel])
    score_vis = gat.score(epochs[sel], y=visibility[sel])
    return np.array(score), np.squeeze(score_vis), np.squeeze(corr_vis)
示例#39
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC
    from sklearn.preprocessing import LabelEncoder
    from sklearn.metrics import mean_squared_error

    raw = io.Raw(raw_fname, preload=False)
    events = read_events(event_name)
    picks = pick_types(raw.info, meg='mag', stim=False, ecg=False,
                       eog=False, exclude='bads')
    picks = picks[0:2]
    decim = 30

    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                        baseline=(None, 0), preload=True, decim=decim)
    # Test default running
    gat = GeneralizationAcrossTime()
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    assert_raises(ValueError, gat.fit, epochs, picks='foo')
    with warnings.catch_warnings(record=True):
        # check classic fit + check manual picks
        gat.fit(epochs, picks=[0])
        # check optional y as array
        gat.fit(epochs, y=epochs.events[:, 2])
        # check optional y as list
        gat.fit(epochs, y=epochs.events[:, 2].tolist())
    assert_equal(len(gat.picks_), len(gat.ch_names), 1)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
                 "prediction, no score>", '%s' % gat)
    assert_equal(gat.ch_names, epochs.ch_names)
    gat.predict(epochs)
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predicted 14 epochs, no score>",
                 "%s" % gat)
    gat.score(epochs)
    gat.score(epochs, y=epochs.events[:, 2])
    gat.score(epochs, y=epochs.events[:, 2].tolist())
    assert_equal("<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
                 "predicted 14 epochs,\n scored "
                 "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.047 (s), length: 0.047 (s), n_time_windows: 15>",
                 "%s" % gat.train_times)
    assert_equal("<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
                 "0.047 (s), length: 0.047 (s), n_time_windows: 15 x 15>",
                 "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    gat_ = copy.deepcopy(gat)
    assert_raises(ValueError, gat_.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] ==
                gat.y_true_.shape[0] ==
                len(gat.y_pred_[0][0]) == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(len(gat.train_times['slices']) == 15 ==
                np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(len(gat.test_times_['slices']) == 15 ==
                np.shape(gat.scores_)[0])
    assert_true(len(gat.test_times_['slices'][0]) == 15 ==
                np.shape(gat.scores_)[1])

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    scores = gat.score(epochs)
    assert_true(isinstance(scores, list))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check

    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.score(epochs)
    assert_true(len(gat.scores_) == len(gat.estimators_) == 8)  # training time
    assert_equal(len(gat.scores_[0]), 15)  # testing time

    # Test start stop training
    gat = GeneralizationAcrossTime(train_times={'start': 0.090,
                                                'stop': 0.250})
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times['times_'][0], epochs.times[6])
    assert_equal(gat.train_times['times_'][-1], epochs.times[9])

    # Test score without passing epochs
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    assert_raises(RuntimeError, gat.score)
    gat.predict(epochs, test_times='diagonal')  # Test diagonal decoding
    scores = gat.score()
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))

    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    gat.predict(epochs[7:])
    assert_raises(ValueError, gat.predict, epochs, test_times='hahahaha')
    assert_raises(RuntimeError, gat.score)
    gat.score(epochs[7:])

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc, predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    assert_raises(ValueError, gat.score, epochs2)
    gat.score(epochs)
    scores = sum(scores, [])  # flatten
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    assert_raises(ValueError, gat.predict, epochs[:10])

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2, 4]  # 4 tested
    # nicely ordered labels or not
    le = LabelEncoder()
    y = le.fit_transform(epochs.events[:, 2])
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Univariate and multivariate prediction
    svc = SVC(C=1, kernel='linear')

    class SVC_proba(SVC):
        def predict(self, x):
            probas = super(SVC_proba, self).predict_proba(x)
            return probas[:, 0]

    svcp = SVC_proba(C=1, kernel='linear', probability=True)
    clfs = [svc, svcp]
    scorers = [None, mean_squared_error]
    # Test all combinations
    for clf, scorer in zip(clfs, scorers):
        for y in ys:
            for n_class in n_classes:
                y_ = y % n_class
                with warnings.catch_warnings(record=True):
                    gat = GeneralizationAcrossTime(cv=2, clf=clf)
                    gat.fit(epochs, y=y_)
                    gat.score(epochs, y=y_, scorer=scorer)
示例#40
0
def test_circular_classifiers():
    from mne.decoding import GeneralizationAcrossTime
    from ..scorers import scorer_angle
    from sklearn.linear_model import Ridge, RidgeCV
    epochs, angles = make_circular_data()
    clf_list = [PolarRegression, AngularRegression,
                SVR_polar, SVR_angle]  # XXX will be deprecated
    for clf_init in clf_list:
        for independent in [False, True]:
            if clf_init in [SVR_polar, SVR_angle]:
                if (not independent):
                    continue
                clf = clf_init(clf=Ridge(random_state=0))
            else:
                clf = clf_init(clf=Ridge(random_state=0),
                               independent=independent)
            print clf_init, independent
            gat = GeneralizationAcrossTime(clf=clf, scorer=scorer_angle)
            gat.fit(epochs, y=angles)
            gat.predict(epochs)
            gat.score(y=angles)
            assert_true(np.abs(gat.scores_[0][0]) < .5)  # chance level
            assert_true(gat.scores_[1][1] > 1.)  # decode
            assert_true(gat.scores_[2][2] > 1.)  # decode
            assert_true(gat.scores_[1][2] < -1.)  # anti-generalize
    # Test args
    gat = GeneralizationAcrossTime(clf=RidgeCV(alphas=[1., 2.]),
                                   scorer=scorer_angle)
    gat.fit(epochs, y=angles)
    gat = GeneralizationAcrossTime(clf=RidgeCV(), scorer=scorer_angle)
    gat.fit(epochs, y=angles)
        # linear regression
        reg = linear_regression(epochs, design_matrix, reg_names)
        reg[c_name].beta.save(fname_reg)

        print 'get ready for decoding ;)'

        train_times = {
            'start': tmin,
            'stop': tmax,
            'length': length,
            'step': step
        }
        cv = KFold(n=len(y), n_folds=n_folds, random_state=random_state)
        gat = GeneralizationAcrossTime(predict_mode='cross-validation',
                                       n_jobs=-1,
                                       train_times=train_times,
                                       scorer=rank_scorer,
                                       clf=clf,
                                       cv=cv)
        gat.fit(epochs, y=y)
        gat.score(epochs, y=y)
        print gat.scores_.shape
        np.save(fname_gat, gat.scores_)

        # store weights
        weights = list()
        for fold in range(n_folds):
            # weights explained: gat.estimator_[time_point][fold].steps[-1][-1].coef_
            weights.append(
                np.vstack([
                    gat.estimators_[idx][fold].steps[-1][-1].coef_
                    for idx in range(len(epochs.times))
# Create epochs to use for classification
n_trial, n_chan, n_time = X.shape
events = np.vstack((range(n_trial), np.zeros(n_trial, int), y.astype(int))).T
chan_names = ['MEG %i' % chan for chan in range(n_chan)]
chan_types = ['mag'] * n_chan
sfreq = 250
info = create_info(chan_names, sfreq, chan_types)
epochs = EpochsArray(data=X, info=info, events=events, verbose=False)
epochs.times = selected_times[:n_time]

# make classifier
clf = LogisticRegression(C=0.0001)

# fit model and score
gat = GeneralizationAcrossTime(
    clf=clf, scorer="roc_auc", cv=cv, predict_method="predict")
gat.fit(epochs, y=y)
gat.score(epochs, y=y)

# Save model
joblib.dump(gat, data_path + "decode_time_gen/gat_ge.jl")

# make matrix plot and save it
fig = gat.plot(
    cmap="viridis", title="Temporal Gen (Classic vs planning) for Global Eff.")
fig.savefig(data_path + "decode_time_gen/gat_matrix_ge.png")

fig = gat.plot_diagonal(
    chance=0.5, title="Temporal Gen (Classic vs planning) for Global eff.")
fig.savefig(data_path + "decode_time_gen/gat_diagonal_ge.png")
示例#43
0
# Create epochs to use for classification
n_trial, n_chan, n_time = X.shape
events = np.vstack((range(n_trial), np.zeros(n_trial, int), y.astype(int))).T
chan_names = ['MEG %i' % chan for chan in range(n_chan)]
chan_types = ['mag'] * n_chan
sfreq = 250
info = create_info(chan_names, sfreq, chan_types)
epochs = EpochsArray(data=X, info=info, events=events, verbose=False)
epochs.times = selected_times[:n_time]

# make classifier
clf = LogisticRegression(C=0.0001)

# fit model and score
gat = GeneralizationAcrossTime(clf=clf,
                               scorer="roc_auc",
                               cv=cv,
                               predict_method="predict")
gat.fit(epochs, y=y)
gat.score(epochs, y=y)

# Save model
joblib.dump(gat, data_path + "decode_time_gen/gat_ge.jl")

# make matrix plot and save it
fig = gat.plot(cmap="viridis",
               title="Temporal Gen (Classic vs planning) for Global Eff.")
fig.savefig(data_path + "decode_time_gen/gat_matrix_ge.png")

fig = gat.plot_diagonal(
    chance=0.5, title="Temporal Gen (Classic vs planning) for Global eff.")
fig.savefig(data_path + "decode_time_gen/gat_diagonal_ge.png")
示例#44
0
def test_generalization_across_time():
    """Test time generalization decoding
    """
    from sklearn.svm import SVC

    raw = io.Raw(raw_fname, preload=False)
    events = read_events(event_name)
    picks = pick_types(raw.info,
                       meg='mag',
                       stim=False,
                       ecg=False,
                       eog=False,
                       exclude='bads')
    picks = picks[0:2]
    decim = 30

    # Test on time generalization within one condition
    with warnings.catch_warnings(record=True):
        epochs = Epochs(raw,
                        events,
                        event_id,
                        tmin,
                        tmax,
                        picks=picks,
                        baseline=(None, 0),
                        preload=True,
                        decim=decim)
    # Test default running
    gat = GeneralizationAcrossTime()
    assert_equal("<GAT | no fit, no prediction, no score>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), no "
        "prediction, no score>", '%s' % gat)
    gat.predict(epochs)
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
        "predict_type : 'predict' on 15 epochs, no score>", "%s" % gat)
    gat.score(epochs)
    assert_equal(
        "<GAT | fitted, start : -0.200 (s), stop : 0.499 (s), "
        "predict_type : 'predict' on 15 epochs,\n scored "
        "(accuracy_score)>", "%s" % gat)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs, y=epochs.events[:, 2])

    old_type = gat.predict_type
    gat.predict_type = 'foo'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_type = old_type

    old_mode = gat.predict_mode
    gat.predict_mode = 'super-foo-mode'
    assert_raises(ValueError, gat.predict, epochs)
    gat.predict_mode = old_mode

    gat.score(epochs, y=epochs.events[:, 2])
    assert_true("accuracy_score" in '%s' % gat.scorer_)
    epochs2 = epochs.copy()

    # check _DecodingTime class
    assert_equal(
        "<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
        "0.047 (s), length: 0.047 (s), n_time_windows: 15>",
        "%s" % gat.train_times)
    assert_equal(
        "<DecodingTime | start: -0.200 (s), stop: 0.499 (s), step: "
        "0.047 (s), length: 0.047 (s), n_time_windows: 15 x 15>",
        "%s" % gat.test_times_)

    # the y-check
    gat.predict_mode = 'mean-prediction'
    epochs2.events[:, 2] += 10
    assert_raises(ValueError, gat.score, epochs2)
    gat.predict_mode = 'cross-validation'

    # Test basics
    # --- number of trials
    assert_true(gat.y_train_.shape[0] == gat.y_true_.shape[0] ==
                gat.y_pred_.shape[2] == 14)
    # ---  number of folds
    assert_true(np.shape(gat.estimators_)[1] == gat.cv)
    # ---  length training size
    assert_true(
        len(gat.train_times['slices']) == 15 == np.shape(gat.estimators_)[0])
    # ---  length testing sizes
    assert_true(
        len(gat.test_times_['slices']) == 15 == np.shape(gat.scores_)[0])
    assert_true(
        len(gat.test_times_['slices'][0]) == 15 == np.shape(gat.scores_)[1])

    # Test longer time window
    gat = GeneralizationAcrossTime(train_times={'length': .100})
    with warnings.catch_warnings(record=True):
        gat2 = gat.fit(epochs)
    assert_true(gat is gat2)  # return self
    assert_true(hasattr(gat2, 'cv_'))
    assert_true(gat2.cv_ != gat.cv)
    scores = gat.score(epochs)
    assert_true(isinstance(scores, list))  # type check
    assert_equal(len(scores[0]), len(scores))  # shape check

    assert_equal(len(gat.test_times_['slices'][0][0]), 2)
    # Decim training steps
    gat = GeneralizationAcrossTime(train_times={'step': .100})
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    gat.score(epochs)
    assert_equal(len(gat.scores_), 8)

    # Test start stop training
    gat = GeneralizationAcrossTime(train_times={'start': 0.090, 'stop': 0.250})
    # predict without fit
    assert_raises(RuntimeError, gat.predict, epochs)
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.score(epochs)
    assert_equal(len(gat.scores_), 4)
    assert_equal(gat.train_times['times_'][0], epochs.times[6])
    assert_equal(gat.train_times['times_'][-1], epochs.times[9])

    # Test diagonal decoding
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    scores = gat.score(epochs, test_times='diagonal')
    assert_true(scores is gat.scores_)
    assert_equal(np.shape(gat.scores_), (15, 1))

    # Test generalization across conditions
    gat = GeneralizationAcrossTime(predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs[0:6])
    gat.predict(epochs[7:])
    assert_raises(ValueError, gat.predict, epochs, test_times='hahahaha')
    gat.score(epochs[7:])

    svc = SVC(C=1, kernel='linear', probability=True)
    gat = GeneralizationAcrossTime(clf=svc,
                                   predict_type='predict_proba',
                                   predict_mode='mean-prediction')
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)

    # sklearn needs it: c.f.
    # https://github.com/scikit-learn/scikit-learn/issues/2723
    # and http://bit.ly/1u7t8UT
    assert_raises(ValueError, gat.score, epochs2)
    gat.score(epochs)
    scores = sum(scores, [])  # flatten
    assert_true(0.0 <= np.min(scores) <= 1.0)
    assert_true(0.0 <= np.max(scores) <= 1.0)

    # test various predict_type
    gat = GeneralizationAcrossTime(clf=svc, predict_type="predict_proba")
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    # check that 2 class probabilistic estimates are [p, 1-p]
    assert_true(gat.y_pred_.shape[3] == 2)
    gat.score(epochs)
    # check that continuous prediction leads to AUC rather than accuracy
    assert_true("roc_auc_score" in '%s' % gat.scorer_)

    gat = GeneralizationAcrossTime(predict_type="decision_function")
    # XXX Sklearn doesn't like non-binary inputs. We could binarize the data,
    # or change Sklearn default behavior
    epochs.events[:, 2][epochs.events[:, 2] == 3] = 0
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    # check that 2 class non-probabilistic continuous estimates are [distance]
    assert_true(gat.y_pred_.shape[3] == 1)
    gat.score(epochs)
    # check that continuous prediction leads to AUC rather than accuracy
    assert_true("roc_auc_score" in '%s' % gat.scorer_)

    # Test that gets error if train on one dataset, test on another, and don't
    # specify appropriate cv:
    gat = GeneralizationAcrossTime()
    with warnings.catch_warnings(record=True):
        gat.fit(epochs)
    gat.predict(epochs)
    assert_raises(ValueError, gat.predict, epochs[:10])

    # Test combinations of complex scenarios
    # 2 or more distinct classes
    n_classes = [2]  # 4 tested
    # nicely ordered labels or not
    y = epochs.events[:, 2]
    y[len(y) // 2:] += 2
    ys = (y, y + 1000)
    # Classifier and regressor
    svc = SVC(C=1, kernel='linear', probability=True)
    clfs = [svc]  # SVR tested
    # Continuous, and probabilistic estimate
    predict_types = ['predict_proba', 'decision_function']
    # Test all combinations
    for clf_n, clf in enumerate(clfs):
        for y in ys:
            for n_class in n_classes:
                for pt in predict_types:
                    y_ = y % n_class
                    with warnings.catch_warnings(record=True):
                        gat = GeneralizationAcrossTime(cv=2,
                                                       clf=clf,
                                                       predict_type=pt)
                        gat.fit(epochs, y=y_)
                        gat.score(epochs, y=y_)