% Convolution Program
%
% Input sequences f and h, determine Lf, Lh, and specify T
% f=input('first signal f = ')
% h=input('second signal h = ')
% T=input('sampling period T = ')T=0.1
clear all
T=0.1
t=0:T:10;
f=sin(t);
h=0.5*(exp(-t)+exp(-3*t));
Lf=length(f)
Lh=length(h)
for k=1:Lf+Lh-1
    y(k)=0;
    for i=max(1,k-(Lh-1)):min(k,Lf)
        y(k)=y(k)+f(i)*h(k-i+1);
    end
yzsappr(k)=T*y(k);
end
plot(t,yzsappr(1:length(t)))
title('Approximative evaluation of the convolution (zero-state response)')
xlabel('Time')
ylabel('Zero-state approximative response')