Prediction_Estimates_mapping

Prediction Estimates mapping panel

Specify initial estimates, lower boundaries, and upper boundaries for test formulation parameters. In addition, indicate whether a parameter is fixed or estimated. See “Prediction settings tab” for initial value, lower bound, and upper bound options.

All iterative estimation procedures require initial estimates of the parameters. Phoenix can generate initial estimates for built-in models or the values can be entered manually.

For IVIVC models only, some parameters can be assigned fixed values while others are estimated. The fixed command can be used for both modeling and simulating. Fixed parameters use a set value, so are no longer considered parameters. This reduces the number of parameters in the model. As an example, the fraction dissolved (Fdiss) can be fixed to 1.0 to prevent incomplete measurements from biasing other parameter estimates. Note that statistics such as VIF are not computed for fixed parameters.

Note: If the Prediction Estimates data source is an external worksheet, be sure to complete the mapping of Prediction Data prior to mapping Prediction Estimates. Otherwise, the validation fails.

Depending on the selections made in the Prediction tab, context associations for Prediction Estimates can include the following. Required input is highlighted orange in the interface.

None: Columns mapped to this context are not included in any analysis or output.

Sort: The test formulation names that are listed in the Prediction dataset. There can be multiple test formulations used as sort values. This mapping is required. Note that formulation names must be mapped to the Sort context.

Parameter: Test formulation parameters.

Initial: Initial estimates for the parameter.

Fixed or Estimated: Whether the initial parameter is fixed or estimated.

Lower: Lower boundary used for parameter estimates.

Upper: Upper boundary used for parameter estimates.