[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Tftb-help] tfrscalo help
From: |
Eric Chassande-Mottin |
Subject: |
Re: [Tftb-help] tfrscalo help |
Date: |
Mon, 30 Mar 2009 10:29:30 +0200 (CEST) |
User-agent: |
Alpine 2.00 (DEB 1167 2008-08-23) |
"2 * log (10)" in ha =
exp(-(2*log(10)/nha^2)*tha.^2).*exp(i*2*pi*f(ptr)*tha)
in the tfrscalo function.
Why not simply ha = exp (-tha. ^2 /nha^2).*exp (i*2*pi*f (ptr)*tha)?
hi,
I think this makes the wavelet approximately zero mean.
(i.e., integral ha(t) dt ~ 0). this property ensures
that the underlying wavelet transform (= wavelet coefficients
before taking the square modulus to get the scalogram) is
invertible. for a discussion, Flandrin "Temps-frequence"
Hermes, p 83 sec 223 Des exemples temps-echelle.
cheers,
eric
- [Tftb-help] tfrscalo help, MAZUEL Mathieu 222354, 2009/03/27
- Re: [Tftb-help] tfrscalo help,
Eric Chassande-Mottin <=
- Message not available