MATLAB: How to use frequency as input for ifft

Question

I find that I cannot input frequency as input for the funciton ifft. However, my frequency range is really large and my Y vector are corresponding to specific frequencies. How can I also include frequency as a input. Thanks

Answer 1

If you don't have uniformly-spaced frequency sampling, then the IDFT (and in particular the IFFT) doesn't make sense. Its theory is predicated on uniform sampling.

You could always use the integral() command to implement a discretized inverse Fourier transform integral. Alternatively, you could use interp1 to resample the spectrum at uniformly spaced sample locations - then the IDFT/IFFT could be applied.