The code below uses the signal below as an example:
y=5*sin(10*2*pi*x)+3*sin(22*2*pi*x)+cos(13*2*pi*x)+7;
Now the Code:
Now the result:
Hope you find this useful.
Thursday, October 8, 2009
Matlab FFT Frequency Axis Reconstruction
Time and time again, I find myself needing to remember how to accurately reconstruct the frequency axis of an FFT in Matlab. This is one of the ways that I have documented as being a pretty close approximation of the frequency axis. This code will also properly compute the magnitude of each frequency component.
The code below uses the signal below as an example:
Now the Code:
Now the result:
Hope you find this useful.
The code below uses the signal below as an example:
Now the Code:
Now the result:
Hope you find this useful.
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I don't have matlab installed so I cannot verify... But I believe this also works for getting the frequency axis:
ReplyDeletedeltat = x(2)-x(1);
fmax = 1/(2*deltat);
deltaf = 1/(N*deltat);
f_axix = -fmax:deltaf:fmax;