clear

x1 = [2,3,4];
x2 = [3,4,5,6];
x3 = conv(x1,x2)

[x,r] = deconv(x3,x1)

b = [0,1];
a = [3,-4,1];
[R,p,C] = residuez(b,a)



[b,a] = residuez(R,p,C)


stop = 1, pause

b = 1;
a = poly([0.9, 0.9, -0.9]);
[R,p,C] = residuez(b,a)



b = [1,0]; 
a = [1,-0.9];
zplane(b,a)


[H,w] = freqz(b,a,100);

figure(2)
subplot(2,1,1)
plot(w,abs(H))
grid on
ylabel('Magnitude Response')
subplot(2,1,2)
plot(w,angle(H))
grid on



[H,w] = freqz(b,a,200,'whole');

figure(3)
subplot(2,1,1)
plot(w,abs(H))
grid on
ylabel('Magnitude Response')
subplot(2,1,2)
plot(w,angle(H))
grid on
ylabel('Phase')

stop = 2, pause

b = [1,0,0,0,0,0,0,0,-1];
a = 1;
figure(4)
zplane(b,a)

[H,w] = freqz(b,a,200,'whole');

figure(5)
subplot(2,1,1)
plot(w,abs(H))
grid on
ylabel('Magnitude Response')
subplot(2,1,2)
plot(w,angle(H))
grid on
ylabel('Phase')

stop = 3, pause

b = 1;
a = [1,0,0,0,0,0,0,0,-.9];
figure(6)
zplane(b,a)

[H,w] = freqz(b,a,200,'whole');

figure(7)
subplot(2,1,1)
plot(w,abs(H))
grid on
ylabel('Magnitude Response')
subplot(2,1,2)
plot(w,angle(H))
grid on
ylabel('Phase')