x = 0:0.001:1;
u = -1:0.001:1;

%f = x - exp(-x.^2/8) .* cos(6*pi*x);
%figure;
%plot(x, f);
%F = fft(f);

F = fft(x);
f = F - exp(-x.^2/8) .* cos(6*pi*x);
figure;
plot(x, abs(f));



% F1 = ((2*pi)^0.5*2*exp(-8*(pi*(u-3)).^2) + (2*pi)^0.5*2*exp(-8*(pi*(u+3)).^2))/2;
figure;
plot(x, abs(F));
F=fftshift(F);
plot(x, abs(F));