ms11_3.m

《数字信号处理实验(MATLAB版)》这

xn=[ones(1,5),zeros(1,5)];
Nx=length(xn);
Nw=1000;dw=2*pi/Nw;
k=floor((-Nw/2+0.5):(Nw/2+0.5));
for r=0:3
    K=3*r+1;
    nx=0:(K*Nx-1);
    x=xn(mod(nx,Nx)+1)
    Xk=x*(exp(-j*dw*nx'*k))/K;
subplot(4,2,2*r+1),stem(nx,x,'k');
axis([0,K*Nx-1,0,1.1]);
ylabel('x(n)');
subplot(4,2,2*r+2),plot(k*dw,abs(Xk),'k');
axis([-4,4,0,1.1*max(abs(Xk))]);
ylabel('X(k)');
end