%Matlab Program 1-15
%Create transfer function model 
num=[2 5 1];
den=conv([1 1],conv([1 2],[1 3]));
sys_tf=tf(num,den)
disp('Model Cconvertion with tf2ss')
[A,B,C,D]=tf2ss(num,den);
sys_ss1=ss(A,B,C,D)
disp('Model Convertion with ss')
sys_ss2=ss(sys_tf)
disp('Model Canonical convertion with canon')
sys_ss3=canon(sys_tf,'model')
disp('Model Companion canonical convertion with canon')
sys_ss4=canon(sys_tf,'companion')
%Check step response of all models
step(sys_tf,sys_ss1,sys_ss2,sys_ss3,sys_ss4)
%step(sys_tf,sys_ss1)
%step(sys_tf,sys_ss4)