[R] Fourier Analysis Help

[Murray Cooper]

Just a word of caution. Having done a lot of work with 24 hour blood 
pressure and ecg recordings, these series are seldom stationary which 
presents problems with spectral analysis. I don't know what your ultimate 
goal is, but in my work I found it often better to work with subsets, of the 
series, chosen according to the needs of the study. There is an extensive 
literature, on this type of study. If you haven't done so, I encourage you 
to do a literature search.

Murray

----- Original Message ----- 
From: "Vittorio Colagrande" <colavittorio at virgilio.it>
To: <r-help at r-project.org>
Sent: Friday, March 13, 2009 2:46 PM
Subject: [R] Fourier Analysis Help


> Dear R-help members,
>
> To whom it may concern, our research group is conducting a study to 
> evaluate the predictive
> value of 24 hour blood pressure variability.
> We are looking for an R routine that performs a fast Fourier transform 
> spectral analysis
> (with an output of the approximation function of the Fourier and estimates 
> the validity
> of the model for the various harmonics).
> Thanks
> Vittorio Colagrande
> [[alternative HTML version deleted]]
>
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