User`s guide

set
11-198
Remark For discrete-time transfer functions, the convention used to represent the
numerator anddenominatordepends onthe choice ofvariable (see the
tf entry
for details). Like
tf,thesyntaxforset changes to remain consistent with the
choice of variable. For example, if the
Variable property is set to 'z' (the
default),
set(h,'num',[1 2],'den',[1 3 4])
produces the transfer function
However, if you change the
Variable to 'z^–1' (or 'q')by
set(h,'Variable','z^–1'),
the same command
set(h,'num',[1 2],'den',[1 3 4])
now interprets the row vectors [1 2] and [1 3 4] as the polynomials
and and produces:
Table 11-19: FRD Model Properties
Property Name Admissible Property Values
Frequency
Real-valued vector of length -by-1, where is the number of
frequencies
Response
• -by- -by- -dimensional arrayof complexdata forsingle LTImodels
• -by- -by--by- -by- -by- -dimensional array for LTI arrays
Units
String 'rad/s' (default), or 'Hz'
N
f
N
f
N
y
N
u
N
f
N
y
N
u
N
f
S
1
…
S
K
hz()
z 2
+
z
2
3z 4++
----------------------------=
12z
1
–
+
13z
1
–
4z
2
–
++