how to use "ss2tf" in matlab?

[gxangel]

matlab ss2tf

hi hi, i'm a beginner in matlab and have been having problems regarding the "ss2tf" function. i type in:
A=[-2 -2;2 -2]
B=[2;0]
C=eye(2)
D=zeros(2,1)

find ss2tf
and it gives me:
ans: 1 2 3 4 5
instead of:
NUM= 2 2
DEN= 4
which i'm expecting as the ans. can anyone out there help me?

 

[fath]

ss2tf

Help ss2tf

SS2TF State-space to transfer function conversion.
[NUM,DEN] = SS2TF(A,B,C,D,iu) calculates the transfer function:

NUM(s) -1
H(s) = -------- = C(sI-A) B + D
DEN(s)
of the system:
.
x = Ax + Bu
y = Cx + Du

from the iu'th input. Vector DEN contains the coefficients of the
denominator in descending powers of s. The numerator coefficients
are returned in matrix NUM with as many rows as there are
outputs y.