Specifications

2 LTI Models
2-32
sys = ss(1,2,3,4,'InputName','u');
sys.a
and you get the value of the property “a” for the state-space model sys.
ans =
1
Similarly,
sys.a = –1;
resets the state transition matrix for sys to –1.
Unlike standard MATLAB structures, you do not need to type the entire field
name or use upper-case characters. You only need to type the minimum
number of characters sufficient to identify the property name uniquely. Thus
either of the commands
sys.InputName
sys.inputn
produces
ans =
'u'
Any valid syntax for structures extends to LTI objects. For example, given the
TF model
h = tf(1,[1,0],'variable','p');
you can reset the numerator to by typing
h.num{1} = [1 2];
or equivalently, with
h.num{1}(2) = 2;
Additional Insight into LTI Properties
By reading this section, you can learn more about using the Ts, InputName,
OutputName, InputGroup,andOutputGroup LTI properties through a set of
examples. For basic information on
Notes and Userdata, see “Generic
hp
()
1 p
⁄
=
p 2+