# mne.time_frequency.tfr_array_stockwell¶

mne.time_frequency.tfr_array_stockwell(data, sfreq, fmin=None, fmax=None, n_fft=None, width=1.0, decim=1, return_itc=False, n_jobs=1)[source]

Compute power and intertrial coherence using Stockwell (S) transform.

Parameters
datandarray

The signal to transform. Any dimensionality supported as long as the last dimension is time.

sfreqfloat

The sampling frequency.

fmin

The minimum frequency to include. If None defaults to the minimum fft frequency greater than zero.

fmax

The maximum frequency to include. If None defaults to the maximum fft.

n_fft

The length of the windows used for FFT. If None, it defaults to the next power of 2 larger than the signal length.

widthfloat

The width of the Gaussian window. If < 1, increased temporal resolution, if > 1, increased frequency resolution. Defaults to 1. (classical S-Transform).

decimint

The decimation factor on the time axis. To reduce memory usage.

return_itcbool

Return intertrial coherence (ITC) as well as averaged power.

n_jobsint

The number of jobs to run in parallel (default 1). Requires the joblib package.

Returns
st_powerndarray

The multitaper power of the Stockwell transformed data. The last two dimensions are frequency and time.

itcndarray

The intertrial coherence. Only returned if return_itc is True.

freqsndarray

The frequencies.

References

1

Stockwell, R. G. “Why use the S-transform.” AMS Pseudo-differential operators: Partial differential equations and time-frequency analysis 52 (2007): 279-309.

2

Moukadem, A., Bouguila, Z., Abdeslam, D. O, and Dieterlen, A. Stockwell transform optimization applied on the detection of split in heart sounds (2014). Signal Processing Conference (EUSIPCO), 2013 Proceedings of the 22nd European, pages 2015–2019.

3

Wheat, K., Cornelissen, P. L., Frost, S.J, and Peter C. Hansen (2010). During Visual Word Recognition, Phonology Is Accessed within 100 ms and May Be Mediated by a Speech Production Code: Evidence from Magnetoencephalography. The Journal of Neuroscience, 30 (15), 5229-5233.

4

K. A. Jones and B. Porjesz and D. Chorlian and M. Rangaswamy and C. Kamarajan and A. Padmanabhapillai and A. Stimus and H. Begleiter (2006). S-transform time-frequency analysis of P300 reveals deficits in individuals diagnosed with alcoholism. Clinical Neurophysiology 117 2128–2143