Does the wsst() (Wavelet sychrosqueezed transform) function include normalization?

Hi,

I want to aggregate (group mean) wavelet synchrosqueezed transform data from many different sources. I would therefore like some information about whether normalization is performed during this function?

The following link gives some info for the cwt() function. Is it the same with wsst()?

https://uk.mathworks.com/matlabcentral/answers/339748-cwt-m-normalization?s_tid=ans_recom_leaf

Thanks for your help,

Tom

Answer 1

[Sudarsanan A K]

Hello Thomas,

I understand that you are interested in knowing if the normalization is applied in the "wsst()" function in MATLAB.

Here are some points regarding the normalization in "wsst()":

• The "wsst()" function normalizes the analyzing wavelets to preserve the L1 norm.
• An equivalent way to state this is that "wsst()" does not multiply the Fourier transforms of the wavelet bandpass filters by the square root of the scale, as it would result in unequal weighting of different bandpass contributions.

If you want to delve into the functional-level implementation of the "wsst()" function in MATLAB, you can open the function definition using the command:

open wsst

You can additionally refer to the MathWorks documentation for the “wsst()” function in the link:

https://mathworks.com/help/wavelet/ref/wsst.html#responsive_offcanvas

I hope this helps!