LTI s domian to z domain tranformation

clc
clear all
A=[-0.0295 0.0478 0 -9.81;-0.1777 -1.4411 120 0;0.0005 -0.033 -1.5345 0;0 0 1 0]
B=[0;-12.81;-6.59;0]
C=[0 0 0 1]
D=[0]
[num ,dem]=ss2tf(A,B,C,D)
[z,p,k]=tf2zp(num,dem)
t=linspace(0,100,100)
sys=tf(num,dem)
% w=0.1 radian/sec
w=0.1;
ztrans(f,sys)

i want to transform sys to z domain .how i can do it

Answer 1

[Paul]

The c2d() function offers several options

doc c2d