matlab离散傅里叶变换

N=128;w=8*pi/N;
n=0:N-1;
x=exp(-n*w/16).*sin(n*w);
k=linspace(-8,8,100);
for t=1:length(k)
X(t)=sum(x.*(exp(-j*k(t).*n)));
end
subplot(1,1,1);
plot(k,abs(X));
傅里叶变换是时域x的累加和,故需要sum(x.*(exp(-j*k(t).*n)))