User`s guide

Building LTI Arrays
4-17
% Set up the LTI array using stack.
COL1 = stack(1,H11,H21); % The first column of the 2-by-2 array
COL2 = stack(1,H12,H22); % The second column of the 2-by-2 array
H = stack(2, COL1, COL2); % Concatenate the two columns of models.
Notice that this result is very different from the single MIMO LTI model
returned by
H = [H11,H12;H21,H22];
Building LTI Arrays Using tf, zpk, ss, and frd
You can also build LTI arrays using the tf, zpk, ss,andfrd constructors. You
do this by using multidimensional arrays in the input arguments for these
functions.
Specifying Arrays of TF models tf
For TF models, use
sys = tf(num,den)
where
• Both
num and den are multidimensional cell arrays the same s ize as sys (see
“size and nd ims” on p age 4-9).
•
sys(i,j,n1,...,nK) is the (i, j) entry of the transfer matrix for the model
located i n the position of the array.
•
num(i,j,n1,...,nK) is a rowvector representing thenumeratorpolynomial
of
sys(i,j,n1,...,nK).
•
den(i,j,n1,...,nK) is a row vector representing denominator polynomial
of
sys(i,j,n1,...,nK).
See “MIM O T ransf er F unction Models” on page 2- 10 f or related information o n
the specification of single TF models.
Specifying Arrays of ZPK Models Using zpk
For ZPK models, use
sys = zpk(zeros,poles,gains)
n
1
…
n
K
,,()