How to save final states with simout

Question

The simout function description (html and manual) indicates that it is capable of saving initial or final states, however it does not say how to save the final states or indicate to the function how to do this. How do I indicate that I want the final states? (When I run simout, it acts like its assuming initial states).

Answer 1

When you use the Simout function you are quirying the state of the model as it exists. If you did not immediately prior run a simulation then you will have the output as the initial conditions. If you want the final states then you will have to run a simulation.
If you are doing this you may want to incorporate into your reportior the use of the resumeto and resumefrom keywords. See the following from the manual:
Linearizing About a Final Operating Point
To linearize a single-rate system at a certain operating point, you must first perform:
y = sim(model,t,u)
sys = lin(model,{resume});
The resume keyword indicates that the linearization operating point will be the final operating point of the previous simulation. To save the operating point at th
e end of the simulation specify the lin options resumeto=filename and resumefrom=filename.
Alternatively, you can simulate the model until you reach the desired operating point:
y = sim(model,t,u);
Find the state at that operating point:
[x] = simout(model);
Linearize around the operating point:
sys = lin(model,{u0=u(length(t),,x0=x})
Now it sometimes becomes useful to obtain the operating point without running a simulation for this purpose there is a full featured trim function that is documented pretty well in the online manual... Search "trim"
Garrett Thurston
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