how to get the FFT of a pulse

hello, I have to simulate an experimental test that involves a hammering on an object to be tested. from it I measured the acceleration caused and the corresponding FFT, so now I have to simulate the test by creating an impulse by adding two steps (one positive and the other negative) obtained through the "stepin" function. I must then make the FFT of this signal

Answer 1

[Star Strider]

I am not familiar with the ‘stepin’ function. It might be easier to use lsim for this, and design your own input vector or vectors if you need separate positive and negative inputs. You can then calculate the fft of the input vector and the lsim output for each of them.

[Federico]

Ok, thank you for the answer. @Star strider is there another way to simulate the impulse of the hammer and then do the FFT?

[Star Strider]

I am not aware of any, however the problem as stated is a bit ambiguous, so other options may exist.