User`s guide

Extracting and Modifying Subsystems
3-7
To extract the transfer function from the first input to the first output,
type
T(1,1)
Transfer function:
1
-------
s + 0.1
Next reassign to and modify the second input channel of T
by typing
T(1,1) = tf(1,[1 0.5]);
T(:,2) = [ 1 ; tf(0.4,[1 0]) ]
Transfer function from input 1 to output...
1
#1: -------
s + 0.5
s – 1
#2: -------------
s^2 + 2 s + 2
Transfer function from input 2 to output...
#1: 1
0.4
#2: ---
s
Referencing FRD Models Through Frequencies
You can extract subsystems from FRD models, as you do with other LTI model
types, by indexing into input a nd output (I/O) d imensions. You can also extract
subsyste ms by indexing into the frequencies of an FRD model.
To index into the frequencies of an FRD model, use the string
'Frequency' (or
any abbreviation, such as,
'freq', as long as it does not conflict with existing
T
11
s
()
T
11
s
()
1 s 0.5
+()⁄