Dilation and translation coefficients in CWT
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Oleg Fedkevich
May 31, 2023, 6:49:36 PM5/31/23
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Dear PyWavelets experts,
I am very new to PyWavelet so I apologize if I missed something in the manual.
For my research I would like to use scalograms produced by CWT.
The example in the PyWavelet manual suggest to use something like
# Decompose our signal
coef, freqs=pywt.cwt(sig, np.arange(1,40), 'mexh', method='conv')
where sig is a 1-D signal given by 1-D array.
This returns me a tuple of coefficients (39 coefficients per each point in my signal).
Now I am getting to the point which confuses me a bit:
when I set np.arange(1,40) do I specify only a number of dilation scales (those which are typically called "a" in the textbook). If it is correct how the translation scale (those which are typically called "b") are chosen? Does the code use 1 translation in time per each point in the signal? Say, if my signal has 128 points does each point define a translation scale ?
Many thanks for your help!
With best regards,
Oleg
I am very new to PyWavelet so I apologize if I missed something in the manual.
For my research I would like to use scalograms produced by CWT.
The example in the PyWavelet manual suggest to use something like
# Decompose our signal
coef, freqs=pywt.cwt(sig, np.arange(1,40), 'mexh', method='conv')
where sig is a 1-D signal given by 1-D array.
This returns me a tuple of coefficients (39 coefficients per each point in my signal).
Now I am getting to the point which confuses me a bit:
when I set np.arange(1,40) do I specify only a number of dilation scales (those which are typically called "a" in the textbook). If it is correct how the translation scale (those which are typically called "b") are chosen? Does the code use 1 translation in time per each point in the signal? Say, if my signal has 128 points does each point define a translation scale ?
Many thanks for your help!
With best regards,
Oleg
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