[r1,p1,k1] = residuez(-4, [16 16 4]);
[r2,p2,k2] = residuez(6, [4 2]);
[r3,p3,k3] = residuez(-4, [1 0 0.64]);

r = [r1' r2' r3'];
p = [p1' p2' p3'];
k = [];

[num,den] = residuez(r,p,k);
tf(num,den,0.1,'variable','z^-1')