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Fourier Transform

Started by Jorge Enrique Prada Rojas April 7, 2005

hi everybody

I just apply a FFT with 1024 samples (k24), to
function (i.e):

y=sin(2*pi*2.48e9*x+0.1*rand(1,1025))+1

After calculating those 1024 values, how can I draw
its power spectrum? How define frequency axis?

Thanks.



Hi,
use plot(FFTSHIFT(FFT(Y)));
You have N samples which corresponds to One Fs(Smapling frequncy)
with fftshift you are displaying Spectrum from -Fs/2 to Fs/2 so your x
axis would be

samples=N/2-1:N/2;
X=samples*Fs/N ;
plot(x , FFTSHIFT(FFT(Y))); Hope this will work

Regards

Chalamala Srinivasa Rao
Tata Consultancy Services Limited

Mailto: chalamala.srao@chal...
Website: http://www.tcs.com
Jorge Enrique Prada Rojas <pradajorge@prad...>
04/07/2005 09:13 AM To
matlab@matl...
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Subject
[matlab] Fourier Transform hi everybody

I just apply a FFT with 1024 samples (k24), to
function (i.e):

y=sin(2*pi*2.48e9*x+0.1*rand(1,1025))+1

After calculating those 1024 values, how can I draw
its power spectrum? How define frequency axis?

Thanks.