User`s guide

Identifying Input-Output Polynomial Models
• Blue minimizes Akaike AIC criterion.
In the AR X M odel Structure Selection window, click any bar to view the
orders that give the best fit. The area on the right is dynamically updated to
show the orders a nd delays that give the best fit.
For m ore information about t he AIC crite rio n, see “Using Akaike’s Criteria to
Validate Models” on page 8-61.
How to Estimate Polynomial Models in the GUI
• “Before You Be gin” on page 3-57
• “Estimating P olyn omial Models in the GUI” on page 3-57
Before You Begin
Before you estimate polynomial models, you must have already imported your
data into the GUI and performed any necessary preprocessing operations. For
more information, see Chapter 1, “Data Processing”.
This procedure also requires that you select a model structure and specify
model orders and delays. For more information about how to estimate model
orders and delays, see “Estimating Orders and Delays in the GUI” on page
3-50.
If you are estimating a multiple-output ARX model, you must specify order
matrices in the MATL AB workspace before estimation, as described in
“Options for Multip le -In put and Mu ltiple-Outpu t ARX Orde rs” on page 3-64.
Estimating Polynomia l Models in the G UI
To estimate a polynomial model in the System Ide ntification To ol GUI.
1 In the System Identification Tool GUI, select Estimate > Linear
parametric models to open the Linear Parametric Models dialog box.
3-57