Creating and Manipulating Models

Reassigning Parts of an LTI Array

You can reassign entire models or portions of models in an LTI array. For example,

• sys = rss(4,3,2,5,2); % 5X2 array of state-space models
  H = rss(4,1,1,5,2);   % 5X2 array of SISO models
  sys(1,2) = H
  

reassigns the subsystem from input two to output one, for all models in the LTI array sys. This SISO subsystem of each model in the LTI array is replaced with the LTI array H of SISO models. This one-line assignment command is equivalent to the following 10-step nested for loop.

• for k = 1:5
    for j = 1:2
      sys(1,2,k,j) = H(:,:,k,j);
    end
  end
  

Notice that you don't have to use the array dimensions with this assignment. This is because I/O selection applies to all models in the array when the array indices are omitted.

Similarly, the commands

• sys(:,:,3,2) = sys(:,:,4,1);
  sys(1,2,3,2) = 0;
  

reassign the entire model in the (3,2) position of the LTI array sys and the (1,2) subsystem of this model, respectively.

Extracting LTI Arrays of Subsystems

Deleting Parts of an LTI Array