dt=0.01; iter=10000;
[x y z]=lorenzo(iter,0.01);
my=z;
Fs=1/dt;
L=length(my);
NFFT = 2^nextpow2(L); % Next power of 2 from length of y
Y = fft(my,NFFT)/L;
f = Fs/2*linspace(0,1,NFFT/2);

% Plot single-sided amplitude spectrum.
st=6;
plot(f(st:NFFT/4),2*abs(Y(st:NFFT/4))) 
title('Single-Sided Amplitude Spectrum of y(t)')
xlabel('Frequency (Hz)')
ylabel('|Y(f)|')