Re: Fourier frequencies
- To: mathgroup at smc.vnet.net
- Subject: [mg43457] Re: Fourier frequencies
- From: "Robert Nowak" <robert.nowak at ims.co.at>
- Date: Wed, 17 Sep 2003 07:59:30 -0400 (EDT)
- References: <bk6imh$gqp$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
hi,
if you have equaly spaced samples x={x1,x2,x3......xn} you simply apply
Fourier[x] the result you get is {f1,f2,f3,....fn} where f1 gives the
constant term f2,fn give the basic frequency, f3,fn-1 give the harmonic with
twice the basic frequency and so on, ...
if you have unevenly spaced samples s={{t1,x1},{t2,x2},.....{tn,xn}} then
you will have to do some nonlinaer fitting, perhaps using NonliearFit[]
regards robert
"akpovo" <akpovo at lmfp.nhmfl.gov> wrote in message
news:bk6imh$gqp$1 at smc.vnet.net...
> Hello to all,
> How possible is it to compute a fourier transform of a data set {t,x} in
> order to have the fourier coefficient and the corresponding frequency?
> Tahnks
>