Specifications

tf
16-222
To do this, type
sys = ss([-2 -1;1 -2],[1 1;2 -1],[1 0],[0 1])
tf(sys)
Transfer function from input 1 to output:
s
-------------
s^2 + 4 s + 5
Transfer function from input 2 to output:
s^2 + 5 s + 8
-------------
s^2 + 4 s + 5
Example 5
You can use a
for loop to specify a 10-by-1 array of SISO TF models.
s = tf('s')
H = tf(zeros(1,1,10));
for k=1:10,
H(:,:,k) = k/(s^2+s+k);
end
The first statement pre-allocates the TF array and fills it with zero transfer
functions.
Discrete-Time
Conventions
The control and digital signal processing (DSP) communities tend to use
different conventions to specify discrete transfer functions. Most control
engineers use the variable and order the numerator and denominator terms
in descending powers of , for example,
A
2– 1–
12–
,= B
11
21–
,= C
10
,= D
01
=
z
z
hz()
z
2
z
2
2z 3++
----------------------------
=