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From:  "A.E lover" <aelover11@gmail.com>
Newsgroups: comp.dsp,comp.soft-sys.matlab
Subject: Re: Normalization for DFT (fft in MATLAB)
Date: Tue, 10 Jul 2007 21:31:32 -0700
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On Jul 10, 11:01 pm, Jerry Avins <j...@ieee.org> wrote:
> A.E lover wrote:
I am using fft of MATLAB,  I am still confused with Tim's method.
In Tim 's method, the testing input is a vector of ones. I am
confused,  I guess it should  be a sinusoidal with amplitude of 1
because my objective is to normalize fft such that the sinusoidal with
applitude of 1 in time domain will correspond with fft amplitude of
unity.
I have tested two cases, using Tim's method, the scale value is the
length of the input vector. while if  the input is a sinusoidal
signal, the scale value is half of signal length. So which one is
correct for my case?



Thanks



> > Thanks Wescott,  however I have a specific requirement to normalize
> > fft: " normalize the FFT output such that a sinusoid with amplitude 1
> > will correspond to an FFT magnitude of unity". I think for this
> > specific requirement we will have unique way to do that, right? So in
> > your opinion, in this case, how should I do to normalize FFT output?
>
> That depends on the details of the FFT routine you use. Write your own
> and know, or use Tim's approach to find out.
>
> Jerry
> --
> Engineering is the art of making what you want from things you can get.
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