ms12_6.m

《数字信号处理实验(MATLAB版)》这

n=0:7;xn=[0,1,2,3,4,5,6,7];
w=linspace(0,2*pi,500);
X=xn*exp(-j*n'*w);            %离散时间傅里叶变换
subplot(3,1,1),stem(n,xn,'k');
ylabel('x(n)');
subplot(3,1,2),plot(w,abs(X),'k');  %显示序列的幅度谱
axis([0,2*pi,1.1*min(abs(X)),1.1*max(abs(X))]);
ylabel('|X(k)|');
subplot(3,1,3),plot(w,angle(X),'k');%显示序列的相位谱
axis([0,2*pi,1.1*min(angle(X)),1.1*max(angle(X))]);
ylabel('angle[X(k)]');