Example #1
0
def cwt_morlet(y, freqs, use_fft=True, n_cycles=3.0, zero_mean=False,
               out='magnitude'):
    """Time frequency decomposition with Morlet wavelets (mne-python)

    Parameters
    ----------
    y : NDVar with time dimension
        Signal.
    freqs : scalar | array
        Frequency/ies of interest. For a scalar, the output will not contain a
        frequency dimension.
    use_fft : bool
        Compute convolution with FFT or temporal convolution.
    n_cycles: float | array of float
        Number of cycles. Fixed number or one per frequency.
    zero_mean : bool
        Make sure the wavelets are zero mean.
    out : 'complex' | 'magnitude' | 'phase'
        Format of the data in the returned NDVar.

    Returns
    -------
    tfr : NDVar
        Time frequency decompositions.
    """
    from mne.time_frequency.tfr import cwt_morlet

    if not y.get_axis('time') == y.ndim - 1:
        raise NotImplementedError
    x = y.x
    x = x.reshape((np.prod(x.shape[:-1]), x.shape[-1]))
    Fs = 1. / y.time.tstep
    if np.isscalar(freqs):
        freqs = [freqs]
        fdim = None
    else:
        fdim = Ordered("frequency", freqs, 'Hz')
        freqs = fdim.values
    x = cwt_morlet(x, Fs, freqs, use_fft, n_cycles, zero_mean)
    if out == 'magnitude':
        x = np.abs(x)
    elif out == 'complex':
        pass
    else:
        raise ValueError("out = %r" % out)

    new_shape = y.x.shape[:-1]
    dims = y.dims[:-1]
    if fdim is not None:
        new_shape += (len(freqs),)
        dims += (fdim,)
    new_shape += y.x.shape[-1:]
    dims += y.dims[-1:]

    x = x.reshape(new_shape)
    info = cs.set_info_cs(y.info, cs.default_info('A'))
    return NDVar(x, dims, info, y.name)
def band_wavelet_synchrony(epochs, start_freq, stop_freq):
    """
    Computes the phase-locking synchrony SPLV for a specific frequency band, by computing the synchrony over all
    frequencies in the [start_freq, stop_freq) band and taking the average.

    :param epochs: The Epochs object for which we compute the wavelet synchrony.
    :param start_freq: The start of the frequency band
    :param stop_freq: The end of the frequency band, excluded from the calculation
    :return: A List of (n_channels x n_channels) lower-triangular ndarrays. Each item in the list corresponds to the
    phase synchrony between the channels for an epoch/window.
    """

    freqs = range(start_freq, stop_freq)
    tf_decompositions = []
    for epoch in epochs:
        # Calculate the Wavelet transform for all freqs in the range
        tfd = cwt_morlet(epoch, epochs.info['sfreq'],
                         freqs, use_fft=True, n_cycles=2)
        n_channels, n_frequencies, n_samples = tfd.shape

        # Calculate the phase synchrony for all frequencies in the range
        av_phase_sync = np.zeros((n_channels, n_channels),
                                 dtype=np.double)
        for frequency_idx in range(n_frequencies):
            freq_tfd = tfd[:, frequency_idx, :]
            freq_phase_diff = np.zeros((n_channels, n_channels),
                                       dtype=np.double)
            for i, ch_i in enumerate(range(0, n_channels)[:-1]):
                for ch_j in range(0, n_channels)[i+1:]:
                    # Get the wavelet coefficients for each channel
                    ch_i_vals = freq_tfd[ch_i, :]
                    ch_j_vals = freq_tfd[ch_j, :]
                    # Phase difference between two channels is derived
                    # from the angle of their wavelet coefficients
                    angles = ((ch_i_vals * ch_j_vals.conjugate()) /
                              (np.absolute(ch_i_vals) * np.absolute(ch_j_vals)))
                    phase_diff = np.absolute(angles.sum() / n_samples)

                    if (phase_diff > 1.0) or (phase_diff < 0.0):
                        sys.stderr.write(("WARNING: Invalid phase difference: "
                                          "%f\n") % phase_diff)
                    # Gather the values in an lower triangular matrix
                    freq_phase_diff[ch_i, ch_j] = phase_diff

            av_phase_sync += freq_phase_diff

        # The synchrony is averaged over the synchronies in all frequencies
        # in the band
        av_phase_sync /= n_frequencies

        tf_decompositions.append(av_phase_sync)

    return tf_decompositions
Example #3
0
def test_time_frequency():
    """Test time frequency transform (PSD and phase lock)
    """
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.5

    # Setup for reading the raw data
    raw = fiff.Raw(raw_fname)
    events = read_events(event_fname)

    include = []
    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = fiff.pick_types(raw.info, meg='grad', eeg=False,
                            stim=False, include=include, exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                        baseline=(None, 0))
    data = epochs.get_data()
    times = epochs.times

    frequencies = np.arange(6, 20, 5)  # define frequencies of interest
    Fs = raw.info['sfreq']  # sampling in Hz
    n_cycles = frequencies / float(4)
    power, phase_lock = induced_power(data, Fs=Fs, frequencies=frequencies,
                                      n_cycles=n_cycles, use_fft=True)

    assert_true(power.shape == (len(picks), len(frequencies), len(times)))
    assert_true(power.shape == phase_lock.shape)
    assert_true(np.sum(phase_lock >= 1) == 0)
    assert_true(np.sum(phase_lock <= 0) == 0)

    power, phase_lock = induced_power(data, Fs=Fs, frequencies=frequencies,
                                       n_cycles=2, use_fft=False)

    assert_true(power.shape == (len(picks), len(frequencies), len(times)))
    assert_true(power.shape == phase_lock.shape)
    assert_true(np.sum(phase_lock >= 1) == 0)
    assert_true(np.sum(phase_lock <= 0) == 0)

    tfr = cwt_morlet(data[0], Fs, frequencies, use_fft=True, n_cycles=2)
    assert_true(tfr.shape == (len(picks), len(frequencies), len(times)))

    single_power = single_trial_power(data, Fs, frequencies, use_fft=False,
                                      n_cycles=2)

    assert_array_almost_equal(np.mean(single_power), power)
Example #4
0
def test_time_frequency():
    """Test time frequency transform (PSD and phase lock)
    """
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.5

    # Setup for reading the raw data
    raw = io.Raw(raw_fname)
    events = read_events(event_fname)

    include = []
    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info, meg='grad', eeg=False,
                            stim=False, include=include, exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    times = epochs.times

    frequencies = np.arange(6, 20, 5)  # define frequencies of interest
    Fs = raw.info['sfreq']  # sampling in Hz
    n_cycles = frequencies / float(4)
    power, phase_lock = induced_power(data, Fs=Fs, frequencies=frequencies,
                                      n_cycles=n_cycles, use_fft=True)

    assert_true(power.shape == (len(picks), len(frequencies), len(times)))
    assert_true(power.shape == phase_lock.shape)
    assert_true(np.sum(phase_lock >= 1) == 0)
    assert_true(np.sum(phase_lock <= 0) == 0)

    power, phase_lock = induced_power(data, Fs=Fs, frequencies=frequencies,
                                      n_cycles=2, use_fft=False)

    assert_true(power.shape == (len(picks), len(frequencies), len(times)))
    assert_true(power.shape == phase_lock.shape)
    assert_true(np.sum(phase_lock >= 1) == 0)
    assert_true(np.sum(phase_lock <= 0) == 0)

    tfr = cwt_morlet(data[0], Fs, frequencies, use_fft=True, n_cycles=2)
    assert_true(tfr.shape == (len(picks), len(frequencies), len(times)))

    single_power = single_trial_power(data, Fs, frequencies, use_fft=False,
                                      n_cycles=2)

    assert_array_almost_equal(np.mean(single_power), power)
Example #5
0
def test_time_frequency():
    """Test time frequency transform (PSD and phase lock)
    """
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.5

    # Setup for reading the raw data
    raw = io.Raw(raw_fname)
    events = read_events(event_fname)

    include = []
    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info, meg='grad', eeg=False,
                            stim=False, include=include, exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    times = epochs.times
    nave = len(data)

    freqs = np.arange(6, 20, 5)  # define frequencies of interest
    n_cycles = freqs / 4.

    # Test first with a single epoch
    power, itc = tfr_morlet(epochs[0], freqs=freqs, n_cycles=n_cycles,
                            use_fft=True, return_itc=True)

    power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=n_cycles,
                            use_fft=True, return_itc=True)

    print(itc)  # test repr
    print(itc.ch_names) # test property
    itc = itc + power # test add
    itc = itc - power # test add
    itc -= power
    itc += power

    power.apply_baseline(baseline=(-0.1, 0), mode='logratio')

    assert_true('meg' in power)
    assert_true('grad' in power)
    assert_false('mag' in power)
    assert_false('eeg' in power)

    assert_equal(power.nave, nave)
    assert_equal(itc.nave, nave)
    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=2, use_fft=False,
                            return_itc=True)

    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    Fs = raw.info['sfreq']  # sampling in Hz
    tfr = cwt_morlet(data[0], Fs, freqs, use_fft=True, n_cycles=2)
    assert_true(tfr.shape == (len(picks), len(freqs), len(times)))

    single_power = single_trial_power(data, Fs, freqs, use_fft=False,
                                      n_cycles=2)

    assert_array_almost_equal(np.mean(single_power), power.data)

    power_pick = power.pick_channels(power.ch_names[:10:2])
    assert_equal(len(power_pick.ch_names), len(power.ch_names[:10:2]))
    assert_equal(power_pick.data.shape[0], len(power.ch_names[:10:2]))
    power_drop = power.drop_channels(power.ch_names[1:10:2])
    assert_equal(power_drop.ch_names, power_pick.ch_names)
    assert_equal(power_pick.data.shape[0], len(power_drop.ch_names))

    mne.equalize_channels([power_pick, power_drop])
    assert_equal(power_pick.ch_names, power_drop.ch_names)
    assert_equal(power_pick.data.shape, power_drop.data.shape)
Example #6
0
def test_time_frequency():
    """Test time frequency transform (PSD and phase lock)
    """
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.5

    # Setup for reading the raw data
    raw = io.Raw(raw_fname)
    events = read_events(event_fname)

    include = []
    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info, meg='grad', eeg=False,
                       stim=False, include=include, exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    times = epochs.times
    nave = len(data)

    epochs_nopicks = Epochs(raw, events, event_id, tmin, tmax,
                            baseline=(None, 0))

    freqs = np.arange(6, 20, 5)  # define frequencies of interest
    n_cycles = freqs / 4.

    # Test first with a single epoch
    power, itc = tfr_morlet(epochs[0], freqs=freqs, n_cycles=n_cycles,
                            use_fft=True, return_itc=True)
    # Now compute evoked
    evoked = epochs.average()
    power_evoked = tfr_morlet(evoked, freqs, n_cycles, use_fft=True,
                              return_itc=False)
    assert_raises(ValueError, tfr_morlet, evoked, freqs, 1., return_itc=True)
    power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=n_cycles,
                            use_fft=True, return_itc=True)
    # Test picks argument
    power_picks, itc_picks = tfr_morlet(epochs_nopicks, freqs=freqs,
                                        n_cycles=n_cycles, use_fft=True,
                                        return_itc=True, picks=picks)
    # the actual data arrays here are equivalent, too...
    assert_array_almost_equal(power.data, power_picks.data)
    assert_array_almost_equal(itc.data, itc_picks.data)
    assert_array_almost_equal(power.data, power_evoked.data)

    print(itc)  # test repr
    print(itc.ch_names)  # test property
    itc += power  # test add
    itc -= power  # test add

    power.apply_baseline(baseline=(-0.1, 0), mode='logratio')

    assert_true('meg' in power)
    assert_true('grad' in power)
    assert_false('mag' in power)
    assert_false('eeg' in power)

    assert_equal(power.nave, nave)
    assert_equal(itc.nave, nave)
    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    # grand average
    itc2 = itc.copy()
    itc2.info['bads'] = [itc2.ch_names[0]]  # test channel drop
    gave = grand_average([itc2, itc])
    assert_equal(gave.data.shape, (itc2.data.shape[0] - 1,
                                   itc2.data.shape[1],
                                   itc2.data.shape[2]))
    assert_equal(itc2.ch_names[1:], gave.ch_names)
    assert_equal(gave.nave, 2)
    itc2.drop_channels(itc2.info["bads"])
    assert_array_almost_equal(gave.data, itc2.data)
    itc2.data = np.ones(itc2.data.shape)
    itc.data = np.zeros(itc.data.shape)
    itc2.nave = 2
    itc.nave = 1
    itc.drop_channels([itc.ch_names[0]])
    combined_itc = combine_tfr([itc2, itc])
    assert_array_almost_equal(combined_itc.data,
                              np.ones(combined_itc.data.shape) * 2 / 3)

    # more tests
    power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=2, use_fft=False,
                            return_itc=True)

    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    Fs = raw.info['sfreq']  # sampling in Hz
    tfr = cwt_morlet(data[0], Fs, freqs, use_fft=True, n_cycles=2)
    assert_true(tfr.shape == (len(picks), len(freqs), len(times)))

    single_power = single_trial_power(data, Fs, freqs, use_fft=False,
                                      n_cycles=2)

    assert_array_almost_equal(np.mean(single_power), power.data)

    power_pick = power.pick_channels(power.ch_names[:10:2])
    assert_equal(len(power_pick.ch_names), len(power.ch_names[:10:2]))
    assert_equal(power_pick.data.shape[0], len(power.ch_names[:10:2]))
    power_drop = power.drop_channels(power.ch_names[1:10:2])
    assert_equal(power_drop.ch_names, power_pick.ch_names)
    assert_equal(power_pick.data.shape[0], len(power_drop.ch_names))

    mne.equalize_channels([power_pick, power_drop])
    assert_equal(power_pick.ch_names, power_drop.ch_names)
    assert_equal(power_pick.data.shape, power_drop.data.shape)

    # Test decimation
    for decim in [2, 3]:
        for use_fft in [True, False]:
            power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=2,
                                    use_fft=use_fft, return_itc=True,
                                    decim=decim)
            assert_equal(power.data.shape[2],
                         np.ceil(float(len(times)) / decim))

    # Test cwt modes
    Ws = morlet(512, [10, 20], n_cycles=2)
    assert_raises(ValueError, cwt, data[0, :, :], Ws, mode='foo')
    for use_fft in [True, False]:
        for mode in ['same', 'valid', 'full']:
            # XXX JRK: full wavelet decomposition needs to be implemented
            if (not use_fft) and mode == 'full':
                assert_raises(ValueError, cwt, data[0, :, :], Ws,
                              use_fft=use_fft, mode=mode)
                continue
            cwt(data[0, :, :], Ws, use_fft=use_fft, mode=mode)
Example #7
0
def test_compute_tfr():
    """Test _compute_tfr function"""
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.498  # Allows exhaustive decimation testing

    # Setup for reading the raw data
    raw = io.read_raw_fif(raw_fname)
    events = read_events(event_fname)

    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info, meg='grad', eeg=False,
                       stim=False, include=[], exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    sfreq = epochs.info['sfreq']
    freqs = np.arange(10, 20, 3).astype(float)

    # Check all combination of options
    for method, use_fft, zero_mean, output in product(
        ('multitaper', 'morlet'), (False, True), (False, True),
        ('complex', 'power', 'phase',
         'avg_power_itc', 'avg_power', 'itc')):
        # Check exception
        if (method == 'multitaper') and (output == 'phase'):
            assert_raises(NotImplementedError, _compute_tfr, data, freqs,
                          sfreq, method=method, output=output)
            continue

        # Check runs
        out = _compute_tfr(data, freqs, sfreq, method=method,
                           use_fft=use_fft, zero_mean=zero_mean,
                           n_cycles=2., output=output)
        # Check shapes
        shape = np.r_[data.shape[:2], len(freqs), data.shape[2]]
        if ('avg' in output) or ('itc' in output):
            assert_array_equal(shape[1:], out.shape)
        else:
            assert_array_equal(shape, out.shape)

        # Check types
        if output in ('complex', 'avg_power_itc'):
            assert_equal(np.complex, out.dtype)
        else:
            assert_equal(np.float, out.dtype)
        assert_true(np.all(np.isfinite(out)))

    # Check that functions are equivalent to
    # i) single_trial_power: X, shape (n_signals, n_chans, n_times)
    old_power = single_trial_power(data, sfreq, freqs, n_cycles=2.)
    new_power = _compute_tfr(data, freqs, sfreq, n_cycles=2.,
                             method='morlet', output='power')
    assert_array_almost_equal(old_power, new_power)
    old_power = single_trial_power(data, sfreq, freqs, n_cycles=2.,
                                   times=epochs.times, baseline=(-.100, 0),
                                   baseline_mode='ratio')
    new_power = rescale(new_power, epochs.times, (-.100, 0), 'ratio')

    # ii) cwt_morlet: X, shape (n_signals, n_times)
    old_complex = cwt_morlet(data[0], sfreq, freqs, n_cycles=2.)
    new_complex = _compute_tfr(data[[0]], freqs, sfreq, n_cycles=2.,
                               method='morlet', output='complex')
    assert_array_almost_equal(old_complex, new_complex[0])

    # Check errors params
    for _data in (None, 'foo', data[0]):
        assert_raises(ValueError, _compute_tfr, _data, freqs, sfreq)
    for _freqs in (None, 'foo', [[0]]):
        assert_raises(ValueError, _compute_tfr, data, _freqs, sfreq)
    for _sfreq in (None, 'foo'):
        assert_raises(ValueError, _compute_tfr, data, freqs, _sfreq)
    for key in ('output', 'method', 'use_fft', 'decim', 'n_jobs'):
        for value in (None, 'foo'):
            kwargs = {key: value}  # FIXME pep8
            assert_raises(ValueError, _compute_tfr, data, freqs, sfreq,
                          **kwargs)

    # No time_bandwidth param in morlet
    assert_raises(ValueError, _compute_tfr, data, freqs, sfreq,
                  method='morlet', time_bandwidth=1)
    # No phase in multitaper XXX Check ?
    assert_raises(NotImplementedError, _compute_tfr, data, freqs, sfreq,
                  method='multitaper', output='phase')

    # Inter-trial coherence tests
    out = _compute_tfr(data, freqs, sfreq, output='itc', n_cycles=2.)
    assert_true(np.sum(out >= 1) == 0)
    assert_true(np.sum(out <= 0) == 0)

    # Check decim shapes
    # 2: multiple of len(times) even
    # 3: multiple odd
    # 8: not multiple, even
    # 9: not multiple, odd
    for decim in (2, 3, 8, 9, slice(0, 2), slice(1, 3), slice(2, 4)):
        _decim = slice(None, None, decim) if isinstance(decim, int) else decim
        n_time = len(np.arange(data.shape[2])[_decim])
        shape = np.r_[data.shape[:2], len(freqs), n_time]
        for method in ('multitaper', 'morlet'):
            # Single trials
            out = _compute_tfr(data, freqs, sfreq, method=method,
                               decim=decim, n_cycles=2.)
            assert_array_equal(shape, out.shape)
            # Averages
            out = _compute_tfr(data, freqs, sfreq, method=method,
                               decim=decim, output='avg_power',
                               n_cycles=2.)
            assert_array_equal(shape[1:], out.shape)
Example #8
0
def test_compute_tfr():
    """Test _compute_tfr function"""
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.498  # Allows exhaustive decimation testing

    # Setup for reading the raw data
    raw = io.read_raw_fif(raw_fname)
    events = read_events(event_fname)

    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info, meg='grad', eeg=False,
                       stim=False, include=[], exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    sfreq = epochs.info['sfreq']
    freqs = np.arange(10, 20, 3).astype(float)

    # Check all combination of options
    for method, use_fft, zero_mean, output in product(
        ('multitaper', 'morlet'), (False, True), (False, True),
        ('complex', 'power', 'phase',
         'avg_power_itc', 'avg_power', 'itc')):
        # Check exception
        if (method == 'multitaper') and (output == 'phase'):
            assert_raises(NotImplementedError, _compute_tfr, data, freqs,
                          sfreq, method=method, output=output)
            continue

        # Check runs
        out = _compute_tfr(data, freqs, sfreq, method=method,
                           use_fft=use_fft, zero_mean=zero_mean,
                           n_cycles=2., output=output)
        # Check shapes
        shape = np.r_[data.shape[:2], len(freqs), data.shape[2]]
        if ('avg' in output) or ('itc' in output):
            assert_array_equal(shape[1:], out.shape)
        else:
            assert_array_equal(shape, out.shape)

        # Check types
        if output in ('complex', 'avg_power_itc'):
            assert_equal(np.complex, out.dtype)
        else:
            assert_equal(np.float, out.dtype)
        assert_true(np.all(np.isfinite(out)))

    # Check that functions are equivalent to
    # i) single_trial_power: X, shape (n_signals, n_chans, n_times)
    old_power = single_trial_power(data, sfreq, freqs, n_cycles=2.)
    new_power = _compute_tfr(data, freqs, sfreq, n_cycles=2.,
                             method='morlet', output='power')
    assert_array_almost_equal(old_power, new_power)
    old_power = single_trial_power(data, sfreq, freqs, n_cycles=2.,
                                   times=epochs.times, baseline=(-.100, 0),
                                   baseline_mode='ratio')
    new_power = rescale(new_power, epochs.times, (-.100, 0), 'ratio')

    # ii) cwt_morlet: X, shape (n_signals, n_times)
    old_complex = cwt_morlet(data[0], sfreq, freqs, n_cycles=2.)
    new_complex = _compute_tfr(data[[0]], freqs, sfreq, n_cycles=2.,
                               method='morlet', output='complex')
    assert_array_almost_equal(old_complex, new_complex[0])

    # Check errors params
    for _data in (None, 'foo', data[0]):
        assert_raises(ValueError, _compute_tfr, _data, freqs, sfreq)
    for _freqs in (None, 'foo', [[0]]):
        assert_raises(ValueError, _compute_tfr, data, _freqs, sfreq)
    for _sfreq in (None, 'foo'):
        assert_raises(ValueError, _compute_tfr, data, freqs, _sfreq)
    for key in ('output', 'method', 'use_fft', 'decim', 'n_jobs'):
        for value in (None, 'foo'):
            kwargs = {key: value}  # FIXME pep8
            assert_raises(ValueError, _compute_tfr, data, freqs, sfreq,
                          **kwargs)

    # No time_bandwidth param in morlet
    assert_raises(ValueError, _compute_tfr, data, freqs, sfreq,
                  method='morlet', time_bandwidth=1)
    # No phase in multitaper XXX Check ?
    assert_raises(NotImplementedError, _compute_tfr, data, freqs, sfreq,
                  method='multitaper', output='phase')

    # Inter-trial coherence tests
    out = _compute_tfr(data, freqs, sfreq, output='itc', n_cycles=2.)
    assert_true(np.sum(out >= 1) == 0)
    assert_true(np.sum(out <= 0) == 0)

    # Check decim shapes
    # 2: multiple of len(times) even
    # 3: multiple odd
    # 8: not multiple, even
    # 9: not multiple, odd
    for decim in (2, 3, 8, 9, slice(0, 2), slice(1, 3), slice(2, 4)):
        _decim = slice(None, None, decim) if isinstance(decim, int) else decim
        n_time = len(np.arange(data.shape[2])[_decim])
        shape = np.r_[data.shape[:2], len(freqs), n_time]
        for method in ('multitaper', 'morlet'):
            # Single trials
            out = _compute_tfr(data, freqs, sfreq, method=method,
                               decim=decim, n_cycles=2.)
            assert_array_equal(shape, out.shape)
            # Averages
            out = _compute_tfr(data, freqs, sfreq, method=method,
                               decim=decim, output='avg_power',
                               n_cycles=2.)
            assert_array_equal(shape[1:], out.shape)
Example #9
0
def test_time_frequency():
    """Test the to-be-deprecated time frequency transform (PSD and ITC)"""
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.498  # Allows exhaustive decimation testing

    # Setup for reading the raw data
    raw = io.read_raw_fif(raw_fname)
    events = read_events(event_fname)

    include = []
    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info, meg='grad', eeg=False,
                       stim=False, include=include, exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    times = epochs.times
    nave = len(data)

    epochs_nopicks = Epochs(raw, events, event_id, tmin, tmax,
                            baseline=(None, 0))

    freqs = np.arange(6, 20, 5)  # define frequencies of interest
    n_cycles = freqs / 4.

    # Test first with a single epoch
    power, itc = tfr_morlet(epochs[0], freqs=freqs, n_cycles=n_cycles,
                            use_fft=True, return_itc=True)
    # Now compute evoked
    evoked = epochs.average()
    power_evoked = tfr_morlet(evoked, freqs, n_cycles, use_fft=True,
                              return_itc=False)
    assert_raises(ValueError, tfr_morlet, evoked, freqs, 1., return_itc=True)
    power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=n_cycles,
                            use_fft=True, return_itc=True)
    power_, itc_ = tfr_morlet(epochs, freqs=freqs, n_cycles=n_cycles,
                              use_fft=True, return_itc=True, decim=slice(0, 2))
    # Test picks argument and average parameter
    assert_raises(ValueError, tfr_morlet, epochs, freqs=freqs,
                  n_cycles=n_cycles, return_itc=True, average=False)

    power_picks, itc_picks = \
        tfr_morlet(epochs_nopicks,
                   freqs=freqs, n_cycles=n_cycles, use_fft=True,
                   return_itc=True, picks=picks, average=True)

    epochs_power_picks = \
        tfr_morlet(epochs_nopicks,
                   freqs=freqs, n_cycles=n_cycles, use_fft=True,
                   return_itc=False, picks=picks, average=False)
    power_picks_avg = epochs_power_picks.average()
    # the actual data arrays here are equivalent, too...
    assert_array_almost_equal(power.data, power_picks.data)
    assert_array_almost_equal(power.data, power_picks_avg.data)
    assert_array_almost_equal(itc.data, itc_picks.data)
    assert_array_almost_equal(power.data, power_evoked.data)

    print(itc)  # test repr
    print(itc.ch_names)  # test property
    itc += power  # test add
    itc -= power  # test add

    power.apply_baseline(baseline=(-0.1, 0), mode='logratio')

    assert_true('meg' in power)
    assert_true('grad' in power)
    assert_false('mag' in power)
    assert_false('eeg' in power)

    assert_equal(power.nave, nave)
    assert_equal(itc.nave, nave)
    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(power_.data.shape == (len(picks), len(freqs), 2))
    assert_true(power_.data.shape == itc_.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    # grand average
    itc2 = itc.copy()
    itc2.info['bads'] = [itc2.ch_names[0]]  # test channel drop
    gave = grand_average([itc2, itc])
    assert_equal(gave.data.shape, (itc2.data.shape[0] - 1,
                                   itc2.data.shape[1],
                                   itc2.data.shape[2]))
    assert_equal(itc2.ch_names[1:], gave.ch_names)
    assert_equal(gave.nave, 2)
    itc2.drop_channels(itc2.info["bads"])
    assert_array_almost_equal(gave.data, itc2.data)
    itc2.data = np.ones(itc2.data.shape)
    itc.data = np.zeros(itc.data.shape)
    itc2.nave = 2
    itc.nave = 1
    itc.drop_channels([itc.ch_names[0]])
    combined_itc = combine_tfr([itc2, itc])
    assert_array_almost_equal(combined_itc.data,
                              np.ones(combined_itc.data.shape) * 2 / 3)

    # more tests
    power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=2, use_fft=False,
                            return_itc=True)

    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    Fs = raw.info['sfreq']  # sampling in Hz
    tfr = cwt_morlet(data[0], Fs, freqs, use_fft=True, n_cycles=2)
    assert_true(tfr.shape == (len(picks), len(freqs), len(times)))
    tfr2 = cwt_morlet(data[0], Fs, freqs, use_fft=True, n_cycles=2,
                      decim=slice(0, 2))
    assert_true(tfr2.shape == (len(picks), len(freqs), 2))

    single_power = single_trial_power(data, Fs, freqs, use_fft=False,
                                      n_cycles=2)
    single_power2 = single_trial_power(data, Fs, freqs, use_fft=False,
                                       n_cycles=2, decim=slice(0, 2))
    single_power3 = single_trial_power(data, Fs, freqs, use_fft=False,
                                       n_cycles=2, decim=slice(1, 3))
    single_power4 = single_trial_power(data, Fs, freqs, use_fft=False,
                                       n_cycles=2, decim=slice(2, 4))

    assert_array_almost_equal(np.mean(single_power, axis=0), power.data)
    assert_array_almost_equal(np.mean(single_power2, axis=0),
                              power.data[:, :, :2])
    assert_array_almost_equal(np.mean(single_power3, axis=0),
                              power.data[:, :, 1:3])
    assert_array_almost_equal(np.mean(single_power4, axis=0),
                              power.data[:, :, 2:4])

    power_pick = power.pick_channels(power.ch_names[:10:2])
    assert_equal(len(power_pick.ch_names), len(power.ch_names[:10:2]))
    assert_equal(power_pick.data.shape[0], len(power.ch_names[:10:2]))
    power_drop = power.drop_channels(power.ch_names[1:10:2])
    assert_equal(power_drop.ch_names, power_pick.ch_names)
    assert_equal(power_pick.data.shape[0], len(power_drop.ch_names))

    mne.equalize_channels([power_pick, power_drop])
    assert_equal(power_pick.ch_names, power_drop.ch_names)
    assert_equal(power_pick.data.shape, power_drop.data.shape)

    # Test decimation:
    # 2: multiple of len(times) even
    # 3: multiple odd
    # 8: not multiple, even
    # 9: not multiple, odd
    for decim in [2, 3, 8, 9]:
        for use_fft in [True, False]:
            power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=2,
                                    use_fft=use_fft, return_itc=True,
                                    decim=decim)
            assert_equal(power.data.shape[2],
                         np.ceil(float(len(times)) / decim))
    freqs = range(50, 55)
    decim = 2
    _, n_chan, n_time = data.shape
    tfr = cwt_morlet(data[0, :, :], sfreq=epochs.info['sfreq'],
                     freqs=freqs, decim=decim)
    assert_equal(tfr.shape, (n_chan, len(freqs), n_time // decim))

    # Test cwt modes
    Ws = morlet(512, [10, 20], n_cycles=2)
    assert_raises(ValueError, cwt, data[0, :, :], Ws, mode='foo')
    for use_fft in [True, False]:
        for mode in ['same', 'valid', 'full']:
            # XXX JRK: full wavelet decomposition needs to be implemented
            if (not use_fft) and mode == 'full':
                assert_raises(ValueError, cwt, data[0, :, :], Ws,
                              use_fft=use_fft, mode=mode)
                continue
            cwt(data[0, :, :], Ws, use_fft=use_fft, mode=mode)

    # Test decim parameter checks
    assert_raises(TypeError, single_trial_power, data, Fs, freqs,
                  use_fft=False, n_cycles=2, decim=None)
    assert_raises(TypeError, tfr_morlet, epochs, freqs=freqs,
                  n_cycles=n_cycles, use_fft=True, return_itc=True,
                  decim='decim')
Example #10
0
def test_time_frequency():
    """Test time frequency transform (PSD and phase lock)
    """
    # Set parameters
    event_id = 1
    tmin = -0.2
    tmax = 0.5

    # Setup for reading the raw data
    raw = io.Raw(raw_fname)
    events = read_events(event_fname)

    include = []
    exclude = raw.info['bads'] + ['MEG 2443', 'EEG 053']  # bads + 2 more

    # picks MEG gradiometers
    picks = pick_types(raw.info,
                       meg='grad',
                       eeg=False,
                       stim=False,
                       include=include,
                       exclude=exclude)

    picks = picks[:2]
    epochs = Epochs(raw,
                    events,
                    event_id,
                    tmin,
                    tmax,
                    picks=picks,
                    baseline=(None, 0))
    data = epochs.get_data()
    times = epochs.times
    nave = len(data)

    epochs_nopicks = Epochs(raw,
                            events,
                            event_id,
                            tmin,
                            tmax,
                            baseline=(None, 0))

    freqs = np.arange(6, 20, 5)  # define frequencies of interest
    n_cycles = freqs / 4.

    # Test first with a single epoch
    power, itc = tfr_morlet(epochs[0],
                            freqs=freqs,
                            n_cycles=n_cycles,
                            use_fft=True,
                            return_itc=True)
    # Now compute evoked
    evoked = epochs.average()
    power_evoked = tfr_morlet(evoked,
                              freqs,
                              n_cycles,
                              use_fft=True,
                              return_itc=False)
    assert_raises(ValueError, tfr_morlet, evoked, freqs, 1., return_itc=True)
    power, itc = tfr_morlet(epochs,
                            freqs=freqs,
                            n_cycles=n_cycles,
                            use_fft=True,
                            return_itc=True)
    # Test picks argument
    power_picks, itc_picks = tfr_morlet(epochs_nopicks,
                                        freqs=freqs,
                                        n_cycles=n_cycles,
                                        use_fft=True,
                                        return_itc=True,
                                        picks=picks)
    # the actual data arrays here are equivalent, too...
    assert_array_almost_equal(power.data, power_picks.data)
    assert_array_almost_equal(itc.data, itc_picks.data)
    assert_array_almost_equal(power.data, power_evoked.data)

    print(itc)  # test repr
    print(itc.ch_names)  # test property
    itc += power  # test add
    itc -= power  # test add

    power.apply_baseline(baseline=(-0.1, 0), mode='logratio')

    assert_true('meg' in power)
    assert_true('grad' in power)
    assert_false('mag' in power)
    assert_false('eeg' in power)

    assert_equal(power.nave, nave)
    assert_equal(itc.nave, nave)
    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    # grand average
    itc2 = itc.copy()
    itc2.info['bads'] = [itc2.ch_names[0]]  # test channel drop
    gave = grand_average([itc2, itc])
    assert_equal(
        gave.data.shape,
        (itc2.data.shape[0] - 1, itc2.data.shape[1], itc2.data.shape[2]))
    assert_equal(itc2.ch_names[1:], gave.ch_names)
    assert_equal(gave.nave, 2)
    itc2.drop_channels(itc2.info["bads"])
    assert_array_almost_equal(gave.data, itc2.data)
    itc2.data = np.ones(itc2.data.shape)
    itc.data = np.zeros(itc.data.shape)
    itc2.nave = 2
    itc.nave = 1
    itc.drop_channels([itc.ch_names[0]])
    combined_itc = combine_tfr([itc2, itc])
    assert_array_almost_equal(combined_itc.data,
                              np.ones(combined_itc.data.shape) * 2 / 3)

    # more tests
    power, itc = tfr_morlet(epochs,
                            freqs=freqs,
                            n_cycles=2,
                            use_fft=False,
                            return_itc=True)

    assert_true(power.data.shape == (len(picks), len(freqs), len(times)))
    assert_true(power.data.shape == itc.data.shape)
    assert_true(np.sum(itc.data >= 1) == 0)
    assert_true(np.sum(itc.data <= 0) == 0)

    Fs = raw.info['sfreq']  # sampling in Hz
    tfr = cwt_morlet(data[0], Fs, freqs, use_fft=True, n_cycles=2)
    assert_true(tfr.shape == (len(picks), len(freqs), len(times)))

    single_power = single_trial_power(data,
                                      Fs,
                                      freqs,
                                      use_fft=False,
                                      n_cycles=2)

    assert_array_almost_equal(np.mean(single_power), power.data)

    power_pick = power.pick_channels(power.ch_names[:10:2])
    assert_equal(len(power_pick.ch_names), len(power.ch_names[:10:2]))
    assert_equal(power_pick.data.shape[0], len(power.ch_names[:10:2]))
    power_drop = power.drop_channels(power.ch_names[1:10:2])
    assert_equal(power_drop.ch_names, power_pick.ch_names)
    assert_equal(power_pick.data.shape[0], len(power_drop.ch_names))

    mne.equalize_channels([power_pick, power_drop])
    assert_equal(power_pick.ch_names, power_drop.ch_names)
    assert_equal(power_pick.data.shape, power_drop.data.shape)