The Curve Fitting (
) study node provides a simplified interface for performing least-squares parameter estimation. It can be used when the reference data is a function of time or a single parameter, and the multiphysics model result expected to match the data is a single global expression evaluated for a selected study step in the same study.
Choose one of the allowed study steps from the Study step list. Only time dependent study steps are supported. Click the
Go to Source button
) to move to the
Settings window for the selected study node. Enter a global
Model expression, which is evaluated at each time or parameter step where it is compared to the corresponding reference data. You can also click the
Add Expression (
) and
Replace Expression (
) buttons to search through a list of predefined expressions.
Select a Reference data source:
Interpolation function or
User defined. If you choose an interpolation function as data source, its argument column will decide at which time or parameter values the difference between model and reference data is evaluated. When the data source is set to
User defined, enter a
Reference expression or click the
Replace Expression (
) buttons to search through a list of predefined expressions. You can also press Ctrl+Space to add a predefined expression to the text field. The difference between the
Model expression and the
Reference expression is then evaluated at output time steps or parameter values as specified in the selected
Study step.