k1=10;
k2=3;
kt = 9;
m1=5;
m2=9;
tp = 0.4

A = [ 0 1 0 0; (-k1-k2)/m1 0 k2/m1 0; 0 0 0 1; k2/m2 0 -k2/m2 -kt/m2]
B = [0; 1/m1; 0; 0]
C=[1 0 0 0;0 1 0 0;0 0 1 0;0 0 0 1]
D=[0;0;0;0]
% Q = [ 0 1 0 0; (-k1-k2)/m1 0 k2/m1 0; 0 0 0 1; k2/m2 0 -k2/m2 -kt/m2]
% W = [0; 1/m1; 0; 0]
% E = [ 1 0 0 0; 0 0 1 0]
% R = 0;


[Q, W, E, R] = c2dm(A,B,C,D,tp, 'zoh');