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Re: [Tftb-help] problem with TFTB
From: |
Alessandra Iacobucci |
Subject: |
Re: [Tftb-help] problem with TFTB |
Date: |
Tue, 21 Mar 2006 18:11:36 +0100 |
Thank you for your fast answer.
the nonstationarity of the series (which is exactly what I want to
study, that is, the evolution of its frequency content) is another
problem.
What I am trying to say is that the software gives an energy spectral
density (well-defined or not) with peaks only at low frequencies
while the contour plot of the spectrogram distribution (well defined
or not) shows component only around the Nyquist frequency, so it
seems to me that there is an incoherence.
If the use of a non analytic signal disturbs you, you may check this
example (p. 56 of the tutorial)
>> sig2=fmconst(128,.15)+fmconst(128,.35);
>> tfrscalo(sig2,1:128,6,0.05,0.45,128,1);
the right results should be the one in Fig 3.20, p.56, but I got the
following:
untitled.pdf
Description: Adobe PDF document
So in my opinion there might be a problem.
Thanks,
Alessandra
On Mar 21, 2006, at 7:36 PM, George A. Bertos wrote:
In the same topic, is the spectral density calculated legitimate ?
- since
it is using the fft() - which is not applicable for non-stationary
signals.
I think one should use integrate in time and frequency domain based
on the
distribution.
George.
-----Original Message-----
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[mailto:address@hidden On
Behalf Of
Alessandra Iacobucci
Sent: Tuesday, March 21, 2006 7:27 AM
To: address@hidden
Subject: [Tftb-help] problem with TFTB
Hi,
I used previous versions of this toolbox and I am starting to use its
last version.
I obtained the picture I am sending you by the comand:
tfrsp(nameofseries);
I think that either the contour or the energy spectral density plot
is upside down.
I tried also the demos and the same thing happens with command like
tfrwv():
the plot that is produced differs from that shown in the tutorial.
Is this a bug?
Many thanks for you help,
Alessandra
- Re: [Tftb-help] problem with TFTB,
Alessandra Iacobucci <=