program3_4.m

经典《信号与系统》教程的matlab例程,对深入理解信号与系统相关概念有很大帮助

t=-6:0.01:6;
w1=2*pi/5;T=5;tao=2;
f=u(t+T+tao/2)-u(t+T-tao/2)+u(t+tao/2)-u(t-tao/2)+u(t-T+tao/2)-u(t-T-tao/2);
f1=0;
N=input('Type in N:=');
for n=-N:N;
    f1=f1+2*((sin(n*w1*tao/2)+eps)/(n*w1*tao/2+eps)*exp(j*n*w1*t))/5;
end
subplot(311)
plot(t,f,'r:');hold on;title('The approximate curves of f(t)')
plot(t,f1);%text(5,1.5,'N=9');
subplot(312)
n=-N:N;
stem(n,2*((sin(n*w1*tao/2)+eps)./(n*w1*tao/2+eps)/5))