Is there a way to customize the default Morelet coefficient \omega_0 of 0.6 when using cwtft and wcohrence?

According to the documentation on cwtft at https://ch.mathworks.com/help/wavelet/ref/cwtft.html#bsuadvo "The default value of ω0 is 6." I am trying to replicate a result from a paper, for which I need ω0 to be 20 when using wcoherence. Is there a way to change the default value? I have not been able to find anything in the Matlab documentation.

Answer 1

[Maneet Kaur Bagga]

Hi,

As per my understanding you want to change the default value of the Morelet wavelet's central frequency "w0" from "6" to "20".

Referring to the MATLAB documentation of "wcoherence" function, it does not allow direct modification of "w0".

https://in.mathworks.com/help/wavelet/ref/wcoherence.html

As a possible workaround you can design the wavelet transform using "cwtft" function and then compute coherence. Please refer to the following code snippet as an example:

S = struct('name','morl', 'param', 20);  % Custom Morelet wavelet with ω0 = 20
cwtStruct = cwtft({signal, 'scales', 1:64, 'wavelet', S});

You can then perform the wavelet transform separately for both the signals and then use the outputs to compute coherence.

Please refer to the following Mathworks documentation of the "cwtft" function for more information:

https://in.mathworks.com/help/wavelet/ref/cwtft2.html

Hope this helps!