Time wrapping spectrogram or time frequency maps .

I have a EEG signal , where I have located the heel strike location and then epoched it , I did the time frequency decomposition of the each epoch and have to do the time wapping of the time frequency maps . I dont understand how to do it ?

[Shubham]

Hey Celestie,

You can try these steps:

After obtaining the time frequency maps, choose one of them as the reference to which other maps will be aligned. Determine a warping function that describes the transformation or alignment of the time-frequency maps to the reference. There are various warping functions available, such as dynamic time warping, time-frequency reassignment, etc. Apply the warping function to each time-frequency map, transforming its time and frequency coordinates to align with the reference map. This involves shifting and stretching the time and frequency axes of each map to match the reference. Once all the time-frequency maps are aligned to the reference, you can combine them by averaging, summing, or performing statistical analysis to obtain a single time-frequency map representing the average or combined information across epochs.

Useful resourses:

https://in.mathworks.com/help/signal/time-frequency-analysis.html

https://in.mathworks.com/matlabcentral/fileexchange/43156-dynamic-time-warping-dtw

Hope this helps !