Spectrum difference - different number of points

Hi everyone,

I have two signals with two diffrent sampling frequencies. Hence, my frequency vector is diffrent for each fft. I would like to have the diffrence between the two Spectrums i have. However i can not simply substract one result to the other one, since calulcation of fft is not preformed at exactly the same frequencies.

Is there a way to interpolate fft results on a choosen number of points, to be able to do this operation ?

Answer 1

[the cyclist]

You could use interp1 to interpolate one (or both) signals after the fft.

[Benoit Meriot]

Thanks a lot ! i feel ashamed of not finding such a simple solution... In fact i was trying to use interp, and not interp1. That's why it wasn't working...