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.

See [R61], [R62], [R63], [R64] for more information.

Parameters:

data : ndarray

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

sfreq : float

The sampling frequency.

fmin : None, float

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

fmax : None, float

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

n_fft : int | None

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

width : float

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

decim : int

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

return_itc : bool

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

n_jobs : int

Number of parallel jobs to use.
Returns:

st_power : ndarray

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

itc : ndarray

The intertrial coherence. Only returned if return_itc is True.

freqs : ndarray

The frequencies.

See also

mne.time_frequency.tfr_stockwell, mne.time_frequency.tfr_multitaper, mne.time_frequency.tfr_array_multitaper, mne.time_frequency.tfr_morlet, mne.time_frequency.tfr_array_morlet

References

[R61](1, 2) Stockwell, R. G. “Why use the S-transform.” AMS Pseudo-differential operators: Partial differential equations and time-frequency analysis 52 (2007): 279-309.
[R62](1, 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.
[R63](1, 2) 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.
[R64](1, 2) 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