close;
clc;
clear;
n=0:3;
x=cos(%pi*n/2);
subplot(4,1,1)
plot2d3(n,x)
xtitle('x[n]','n')
a=gca();
a.x_location="origin";
a.y_location="right";
poly1=a.children.children;
poly1.thickness=3;
poly1.foreground=2;
plot(n,x,'r.')
subplot(4,1,2)
h=.5^n;
plot2d3(n,h);
xtitle('h[n]','n')
a=gca();
a.x_location="origin";
a.y_location="right";
poly1=a.children.children;
poly1.thickness=3;
poly1.foreground=2;
plot(n,h,'r.')
y=convol(x,h)
subplot(4,1,3)
plot2d3(n,y(1:4));
xtitle('y[n]','n')
plot(n,y(1:4),'r.')
a=gca();
a.x_location="origin";
a.y_location="right";
poly1=a.children.children;
poly1.thickness=3;
poly1.foreground=2;
clear y;
X=fft(x,-1);
H=fft(h,-1);
Y=H.*X;
y=fft(Y,1);
subplot(4,1,4)
plot2d3(n,y);
xtitle('y[n]','n')
plot(n,y,'r.')
a=gca();
a.x_location="origin";
a.y_location="right";
poly1=a.children.children;
poly1.thickness=3;
poly1.foreground=2;
plot(n,x,'r.')