mne.time_frequency.tfr_array_morlet

mne.time_frequency.tfr_array_morlet(epoch_data, sfreq, freqs, n_cycles=7.0, zero_mean=False, use_fft=True, decim=1, output='complex', n_jobs=1, verbose=None)[source]

Compute time-frequency transform using Morlet wavelets.

Convolves epoch data with selected Morlet wavelets.

Parameters
epoch_dataarray of shape (n_epochs, n_channels, n_times)

The epochs.

sfreqfloat | int

Sampling frequency of the data.

freqsarray_like of float, shape (n_freqs,)

The frequencies.

n_cyclesfloat | array of float, default 7.0

Number of cycles in the Morlet wavelet. Fixed number or one per frequency.

zero_meanbool | False

If True, make sure the wavelets have a mean of zero. default False.

use_fftbool

Use the FFT for convolutions or not. default True.

decimint | slice

To reduce memory usage, decimation factor after time-frequency decomposition. default 1 If int, returns tfr[…, ::decim]. If slice, returns tfr[…, decim].

Note

Decimation may create aliasing artifacts, yet decimation is done after the convolutions.

outputstr, default ‘complex’
  • ‘complex’ : single trial complex.

  • ‘power’ : single trial power.

  • ‘phase’ : single trial phase.

  • ‘avg_power’ : average of single trial power.

  • ‘itc’ : inter-trial coherence.

  • ‘avg_power_itc’ : average of single trial power and inter-trial coherence across trials.

n_jobsint

The number of epochs to process at the same time. The parallelization is implemented across channels. default 1

verbosebool, str, int, or None

If not None, override default verbose level (see mne.verbose() and Logging documentation for more).

Returns
outarray

Time frequency transform of epoch_data. If output is in [‘complex’, ‘phase’, ‘power’], then shape of out is (n_epochs, n_chans, n_freqs, n_times), else it is (n_chans, n_freqs, n_times). If output is ‘avg_power_itc’, the real values code for ‘avg_power’ and the imaginary values code for the ‘itc’: out = avg_power + i * itc

Notes

New in version 0.14.0.

Examples using mne.time_frequency.tfr_array_morlet