simple cwt (continuous wavelet transform) axis question

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Francesco
Francesco 2011-7-5
Let's load a dataset and do a cwt on it, where the dataset is a fairly sinusoidal signal with a max amplitude x. I can do cwt by the following:
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man_scale = 1:4:2048;
coefs_pp = cwt(data,man_scale,'gaus8');
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I'm only interested in picking out a particular frequency, so I find the array position corresponding to my wanted frequency, and then have:
-----------------------------------
interest = data(array_position,:);
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My question is simple: What are the units of the resulting variable "interest"?
The values that I get from this don't match at all with the range of "data" (over an order of magnitude different). Not quite sure where it's pulling the values from.
Thanks in advance,

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回答（1 个）

Ashish Uthama
Ashish Uthama 2011-7-6
This series of tutorials might be useful.
interest = data(chosen_scale,:);
I would just think of 'interest' as a measure of similarity of the wavelet at 'chosen_scale' scale at each point in the 'data' array. As the terminology suggests, they are 'coefficients' and as such might not have units associated with them.
From the CWT equation, you might see that the range of magnitudes of the coefficients depends on the signal and the range of the mother wavelet at a given scale.

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