ex5p2.m

关于数字信号处理的一些matlab例程

L=5;
N=20;
k=[-N/2:N/2];
xn=[ones(1,L),zeros(1,N-L)];
Xk=dfs(xn,N);
magXk=abs([Xk(N/2+1:N) Xk(1:N/2+1)]);
subplot(2,2,1);stem(k,magXk);axis([-N/2,N/2,-0.5,5.5])
xlabel('k');ylabel('Xtilde(k)')
title('DFS of SQ.wave:L=5,N=20')
L=5;
N=40;
k=[-N/2:N/2];
xn=[ones(1,L),zeros(1,N-L)];
Xk=dfs(xn,N);
magXk=abs([Xk(N/2+1:N) Xk(1:N/2+1)]);
subplot(2,2,2);stem(k,magXk);axis([-N/2,N/2,-0.5,5.5])
xlabel('k');ylabel('Xtilde(k)')
title('DFS of SQ.wave:L=5,N=40')
L=5;
N=60;
k=[-N/2:N/2];
xn=[ones(1,L),zeros(1,N-L)];
Xk=dfs(xn,N);
magXk=abs([Xk(N/2+1:N) Xk(1:N/2+1)]);
subplot(2,2,3);stem(k,magXk);axis([-N/2,N/2,-0.5,5.5])
xlabel('k');ylabel('Xtilde(k)')
title('DFS of SQ.wave:L=5,N=60')
L=7;
N=60;
k=[-N/2:N/2];
xn=[ones(1,L),zeros(1,N-L)];
Xk=dfs(xn,N);
magXk=abs([Xk(N/2+1:N) Xk(1:N/2+1)]);
subplot(2,2,4);stem(k,magXk);axis([-N/2,N/2,-0.5,7.5])
xlabel('k');ylabel('Xtilde(k)')
title('DFS of SQ.wave:L=7,N=60')