Specifications

5 Arrays of LTI Models
5-8
The next figure illustrates the concepts of dimension and size for the LTI array
m2d, a 2-by-3 array of one-input, two-output transfer function models.
Figure 5-5: Dimensions and Size of m2d, an LTI Array
You can load this sample LTI array into your workspace by typing
load LTIexamples
size(m2d)
2x3 array of continuous-time transfer functions
Each transfer function has 2 outputs and 1 input.
The I/O dimensions correspond to the row and column dimensions of the
transfer matrix. The two I/O dimensions are both of length 1 for SISO models.
For MIMO models the lengths of these dimensions are given by the number of
outputs and inputs of the model.
Five related quantities are pertinent to understanding the array dimensions:
T
h
e
l
e
n
g
t
h
o
f
t
h
e
f
i
r
s
t
a
r
r
a
y
d
i
m
e
n
s
i
o
n
i
s
2
.
The length of the second array dimension is 3.
Input dimension (length 1)
Output dimension (length 2)
3.36
s 2.9+
-----------------
7.23
3.4
s 2.86+
--------------------
7.27
3.45
s 2.81+
--------------------
7.32
m2d(:,:,1,1) m2d(:,:,1,2) m2d(:,:,1,3)
m2d(:,:,2,1) m2d(:,:,2,2) m2d(:,:,2,3)
3.45
s 2.81+
--------------------
7.32
m2d(:,:,2,3)