Is it possible to modify the matrices in a genss ?

Hello everybody!

Do you know if it's possible to change one of the matrices componing a genss (not only the tunable parameter) ?

For example the following system:

a = realp('a', 10); % The tunable parameter
A = [ 0 1; 1 a];
B1 = [1; 0];
B2 = [1 2; 0 1];
C = [1 1];
D = 0;

G = ss(A, B1, C, D);

Now I want to change the B matrix (to cope with more inputs for example) but I don't want to create a new genss (maybe I can't access A, C and D matrices, which could be much more complicated).

My question is: is it possible to change the B1 matrix by the B2 matrix in G ?

It's seems it's not even possible to access the A, B, C and D matrices of G except for the current value (but A won't be a genmat).

Does anybody have any idea ?

Thank you ! Stéphane

Answer 1

[Jon Boerner]

I don't know if you can change the size, but I think you could create some more tunable parameters to fill B, but make sure they are not free:

b = realp('b',[1; 0]);
b.Free = [0;0];
B1 = b;

That way you could change the value of b by hand, and it wouldn't be tuned by whatever you are using the system for.

[Stephen23]

Stephane's "Answer" moved here:

Thank you for your answer, that's a good idea !