Transform function model and Zero-pole-gain model

Note:Define the matrices,num and den,at first

num=[0 2 7 3];

den=[1 6 11 6];

sys=tf(num,den)                                //transform function

[z,p,k]=tf2zp(num,den)                    //transform function to zero-point-gain  function

sys=zpk(z,p,k)                                    //zero-point-gain function

[a,b]=zp2tf(z,p,k)                              //zero-point-gain function to transform function