User`s guide

Estimating Nonlinear G rey-Box Models
• Order — Vector with three entries [Ny Nu Nx], specifying the number of
model outputs
Ny, the number of inputs Nu, and the number of states Nx.
•
Parameters — Parameters, specified as struct arrays, cell arrays, or
double arrays.
•
InitialStates —Specifiedinthesamewayasparameters. Mustbethe
fourth input to the
idnlgrey constructor.
For detailed information about thisobjectanditsproperties,seethe
idnlgrey
reference page.
Use
pem to estimate your grey-box model.
Using pem to Estimate Nonlinear Grey-Box Models
You can use the pem command to estimate the unknown idnlgrey model
parameters and initial states using measured data.
The input-output dimensions of the data must be compatible with the input
and output orders you specified for the
idnlgrey model.
Use the following general estimation syntax:
m = pem(data,m)
where data is the estim ation d ata and m is the idnlgrey model object you
constructed.
You can pass additional property-value pairs to
pem to specify the properties
of the model or the estimation algorithm. Assignable properties include
the ones returned by the
get(idnlgrey) command and the algorithm
properties returned by the
get(idnlgrey, ' Algo rithm'),suchasMaxIter
and Tolerance. For detailed information about the se m o del properties, see
the
idnlgrey reference page.
For more information about validating your models, see Chapter 8, “Model
Analysis”.
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