User`s guide

Representing Time- and Frequency-Domain Data Using iddata Objects
For example, suppose the iddata object data contains three output channels
(named
y1, y2,andy3 ), and four input channels (named u1, u2, u3,andu4).
To select all d a ta samples in
y3, u1,andu4, type the following command at
the prompt:
% Use a ce ll array to reference
% input channels 'u1' and 'u4'
data_sub = data(:,'y3',{'u1','u4'})
or equivalently
% Use channel indexes 1 and 4
% to reference the input channels
data_sub = data(:,3,[1 4])
Tip Use a colon (:) to specify all samples or all channels, and the empty
matrix (
[]) to specify no samples or no channels.
If you want to create a time-series object by extracting only the output data
from an
iddata object, type the follow ing command:
data_ts = data(:,:,[])
You can assign new values to subreferenced variables. For example, the
following command assigns the first10valuesofoutputchannel
1 of data to
values i n samples
101 through 110 in the output channel 2 of data1 .Italso
assigns the first 10 values of input channel
1 of data to values in samples 101
through 110 in the input channel 3 of data1.
data(1:10,1,1) = data1(101:110,2, 3)
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