Re: Fourier transform
- To: mathgroup at smc.vnet.net
- Subject: [mg43521] Re: Fourier transform
- From: "Robert Nowak" <robert.nowak at ims.co.at>
- Date: Fri, 19 Sep 2003 03:41:46 -0400 (EDT)
- References: <bk9jb2$t8b$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
hopefuly im not wrong but i think there exist at least two spektra i.) the amplitude spektrum A ii.) the power spektrum P with simply P=A*A so you might just try: Abs[Fourier[]]^2 regards robert "Ch akpovo" <akpovo at lmfp.nhmfl.gov> wrote in message news:bk9jb2$t8b$1 at smc.vnet.net... > I'm using Time Series Package and I noticed that there is a difference > between the power spectrum computed from the command Spectrum[] and that > using Abs[Fourier[]. I would like to know why that difference and which > method is the best as far as deriving the energy (parseval's theorem) > carried in the data is concerned. > Can anyone help? > -- > ch akpovo > Laboratory for Modern Fluid Physics > Florida A & M University > Phone: 850 561 2473 > Fax: 850 561 2474 > > >