After filtering a Fourier Transform, how can I integrate it?

If I want to get a t vs V graph from a Fourier Transform, how can i integrate it?

Answer 1

[Star Strider]

To filter a signal in the frequency domain, use the Signal Processing Toolbox fftfilt function. (Filtering in frequency space requires that you do the same operation on both the positive and negative frequencies, since the transform is symmetrical. If you only ‘filter’ half of it, the result will be meaningless.)

After you have completed the filtering, use the ifft (inverse Fourier transform) function to transform it back to the time domain.