ex_1.m

信号与系统分析以matlab实现

%p131 2
%(1)
clear all;
[u,k]=stepseq(-5,20,0);%u(k)
k_1=-5:20;
f_1=(-1/2).^k_1;
[f1,k1]=sigmult(u,k,f_1,k_1);%(1/2)^ku(k)
%(2)
[u_2_1,k_2_1]=stepseq(-5,10,0);%u(k)
[u_2_2,k_2_2]=stepseq(-5,10,6);%u(k-6)
k_2=-5:10;
f_2=k_2;%f=k
[u_2,k_2]=sigadd(u_2_1,k_2_1,-u_2_2,k_2_2);%u(k)-u(k-6)
[f2,k2]=sigmult(f_2,k_2,u_2,k_2);%k[u(k)-u(k-6)]
%(3)
[f_3,k_3]=stepseq(-5,10,-2);%u(k+2)
[f3,k3]=sigfold(f_3,k_3);%u(-k+2)
%(4)
[u_4,k_4]=stepseq(-5,20,0);%u(k)
k_4=-5:20;
f_4=sin(k*pi/4);
[f4,k4]=sigmult(u_4,k_4,f_4,k_4);%sin(kpi/4)u(k)
figure(1)
subplot(2,2,1),stem(k1,f1);
subplot(2,2,2),stem(k2,f2);
subplot(2,2,3),stem(k3,f3);
subplot(2,2,4),stem(k4,f4);