clear all;
t=-2:1:6;
x=[0,0,1,1,1,1,1,0,0];

subplot(4,1,1);
stem(t,x);
hold on;
grid on;
axis equal;

tt=-2:1:9;
y=[0,0,0,1,2,3,2.5,2,1.5,1,0.5,0]

subplot(4,1,2);
stem(tt,y);
grid on;
axis equal;

N = length(x) + length(y) -1

subplot(4,1,3);

for n=1:N
    z(n)=0;
    for k=1:n-1

        if k > length(x)
            x(k)=0;
        end
        if n-k > length(y)
                y(n-k)=0;
        end
            z(n)=z(n) + x(k) *y(n-k)
    end
pause;
stem(z);
axis([0,20,0,20]);
hold on;
    end


% subplot(4,1,3);
% stem(z);

z1=conv(x,y);
subplot(4,1,4);
stem(z1);
axis([0,20,0,20]);