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Re: fft, sampling frequency, wavelength
Posted:
Apr 12, 2012 4:59 AM
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> Given the fft of a real-valued waveform with a length of N evenly
> spaced points, the frequency of a peak at the ith point 1<= i <=
> ceil((N+1)/2) will be a fixed fraction of the the sampling frequency
> Fs.
>
> f = (Fs/N)*[ 0:ceil( (N-1)/2 ) ];
> f0 = (Fs/N)(i-1) ;
>
> So, doubling Fs doubles f0, etc.
>
> Greg
Hi Greg,
shouldn't the frequency peaks not change their position on the frequency-axis !?
Could you do fft of the wave (vector a) and tell me what you get? Please!!!
here the needed facts again:
The data genarator produces 61 elements in a second. So the whole length of the vector "a" represent a total time of 50/61=0.82 seconds.
I am grateful for your help.
Solbohak
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