Use N4sid for system identification (for new data estimation)

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Hi,
I am using N4sid toolbox to do a system identification problem. I used the command: "m = n4sid(z, 5,'Form','free', opt);" to create the system based on measured "input" and "output" (contains in z=z = iddata(y', u', 0.2, 'Name', 'heating/cooling load', 'TimeUnit', 's');".
However,I still want to use this model to predict some unmeasured cases. To be more specific, I have a new input measurement U2, I want to used to model to predict the output from U2. How can I realize that? What is command for this estimation using the model from N4sid?
Thanks very much.

Accepted Answer

Rajiv Singh
Rajiv Singh on 3 Jul 2013
Edited: Rajiv Singh on 3 Jul 2013
Computing response of a model to a given input is called simulation. Use the idParametric/sim command for that as in:
Ud = iddata([], U2, .2);
Yd = sim(m, Ud);
Y2 = Yd.y; % the raw response data
See:
  1 Comment
Xiwang
Xiwang on 7 Jul 2013
Thanks very much. Rajiv. Another questions. If I use "ident" tool, and use the "state space model" to train the model, how can I code it in my "mfile"? And how can I apply the model to simulate the new data.
Thanks again.
Xiwang Li

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