User`s guide

Specifying Initial States
You can use the following shortcut syntax for setting initial states to zero:
y=sim(model,data,'InitialState','z')
y=predict(model,data,'InitialState','z ')
Setting Initial States to Equilibrium Values
If you have physical ins ig ht about the starting point of the system, create a
vector of specific initial states at the command line.
Use the followin g syntax to specify initial states for simulation or prediction:
y=sim(model,data,'InitialState',S)
y=predict(model,data,'InitialState',S)
where S represents a vector of initial states.
If you are working with multiexperiment data, specify
S as a matrix
containing as many columns as there are experiments.
Estimating Initial States from the Data
• “How to Estimate States for Simulation ” on pa ge 9-9
• “How to Estimate States for Prediction” on page 9-10
How to Estimate States for Simulation
Simulation using data from a different experiment than the data used to
estimate the m odel requires the correspon d in g initial states.
To use
sim with a data set that differs from the data you used to estimate the
model, first estimate the new initial states
Sest using find stat es:
X0est = findstates(model,data)
Next, specify the estimated initial states Sest as an argument in sim.For
example:
y = sim(model,data,'InitialState',SestX0est)
9-9