Re: Simple Fourier help
- To: mathgroup at smc.vnet.net
- Subject: [mg53258] Re: [mg53237] Simple Fourier help
- From: yehuda ben-shimol <benshimo at bgu.ac.il>
- Date: Mon, 3 Jan 2005 04:29:34 -0500 (EST)
- References: <200501020912.EAA27755@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
This should be s rather simple task, but I need to know the source. Is it a composition of pure sine harmonic functions well separated in frequency, or a more complicated signal? And what is the sampling frequency? Are you sure that you are keeping the Nyquist condition for sampling (at least twice the maximal frequency) in order to avoid the aliasing effect? If all these are met, you need to take the Abs[Fourier[signal-Mean[signal]]]. I order to see it nicely you need to RotateLeft [] (or RotateRight it) according to the number of samples you have. Then you need to find the first five local maxima (that are, point that are larger then both their left and right neighbors), assuming that there are such five harmonic components. If you send me your conditions I'll send you an exact code that generates it yehuda james wrote: >Somebody knows how is possible to find frequency and amplitude for the >most important waves of a primary wave with no complicated >calculation? I need to find at max the first five subwaves. In anyway >there is in the web a software or a site that do that? Thanks > > >
- References:
- Simple Fourier help
- From: attackack@yahoo.com (james)
- Simple Fourier help