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Subject: Re: FFT,IFFT, and NDFT,NFFT
Date: Sat, 27 Jun 2009 21:27:01 +0000 (UTC)
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"guj " <gulatiakshay@gmail.com> wrote in message <h25v6u$5ia$1@fred.mathworks.com>...
> 1. When we have irregular sampling, we can use NDFT on it instead of FFT 
> NDFT equation
> f_j = \sum_{k=-N/2}^{N/2-1} \hat f_k e^{(-2 *pi*i*k*x_j)}
> 
> k= (-N/2:N/2-1)
> x_j=time domain (j=0,1,2____M-1)
> 
> So what my question is, whenever we have non uniform sampling in the one domain will we get uniform sampling in another domain. For ex if my time domain is irregular, will i be getting regular sampling in frequency domain
> 
> 
> 2. Inverting NDFT is not a easy task as in FFT, In ifft A inverse is equal to A conjugate, because of uniform sampling or fixed sampling in time domain that why IFFT is easy to apply. Please correct me if am wrong.
> 
> If any one interested in non uniform sampling, here is one good article
> http://www.mathematik.tu-chemnitz.de/preprint/quellen/2006/PREPRINT_01.pdf
> I didnt understand quiet few things in it, if any one wana discuss..:) will be happy




And Matlab peoples please install latex on server, it will be good to post equations on these threads