I want to ask~ if use linear model
"bar" means steady state~
should i need to use other .mod file to solve steady state?
or I can solve in the same .mod file?
thanks for everyone ^^
For a linear model, where your equations are written in deviations, you need to calculate your steady state separately. Either by hand (analytically or numerically) or alternatively using another MOD-file where you write the full nonlinear model (the save_params_and_steady_state and load_params_and_steady_state commands can help you to transfer the data from one MOD-file to the other).
If your model is not written in deviation, then you can replace the "bar"s by the STEADY_STATE operator.