FFT of Signal doesn´t work well

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Cedric Burkhart on 30 Aug 2021
Edited: Cedric Burkhart on 30 Aug 2021
Hi,
I would like to have a FFT of a constant signal with two Dirac jumps.
My signal is correct, but my FFT shows nothing. May somebody could help me?
It´s the following code:
t = [1:361] ; % in Grad, Gesamtumdrehung sind 360°
f(t(1):t(end)) = 0; % f = Signal
% Magnets
N = 23; % Amount of magnets
n = 2; % selected magnets
a = 360/n ; % distance between magnets
% Signal 1 = Dirac
tsprung = 20;
tsprung2 = tsprung + a;
f(tsprung)= 1;
f(tsprung2)= f(tsprung);
subplot(211);
plot (t,f);
xft = fft(f);
xabs = abs(xft);
subplot(212);
plot (xabs);
set(gca, 'XTick',[0:20:360])
set(gca, 'YTick',[0:0.1:1])
xlabel ('Position der Magneten in Grad');
ylabel ('Stoß');
legend ('Signal');
THANKS A LOT !

KALYAN ACHARJYA on 30 Aug 2021
xabs(2nd Plot) is the absolute of fft ?? Cedric Burkhart on 30 Aug 2021
Yes it should show the absolut numbers of the fft, but if it works without the abs then it will be good as well.
I just wanna see how the frequency-spectrum is before and after the dirac jump.