Dakota Reference Manual: algebraic_mappings

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algebraic_mappings

Use AMPL to define algebraic input-output mappings

## Specification

Alias: none

Argument(s): STRING

Default: no algebraic mappings

## Description

Dakota can evaluate algebraic input-output mappings using AMPL [25]. The mappings are expressed in 3 files: `stub.nl`, `stub.col`, and `stub.row`, where `stub` is a particular root name describing a particular problem. The file names are communicated to Dakota using the `algebraic_mappings` keyword. It may either specify the full `stub.nl` filename, or alternatively, just the `stub` basename.

Dakota then extracts the input and output identifier strings from `stub.col` and `stub.row` and employs the AMPL solver library[28] to process the directed acyclic graphc (DAG) specification in `stub.nl`. The variable and objective function names declared within AMPL should be a subset of the variable and response descriptors specified in the variables and responses blocks. Ordering is not important, as Dakota will reorder data as needed.

## Examples

An interface employing both algebraic and simulation-based mappings. The results from the individual algebraic and simulation mappings are overlaid based on the variable and response descriptors used by the individual mappings.

    interface,
        algebraic_mappings = 'ampl/fma.nl'
        fork
          analysis_driver = 'text_book'
          parameters_file = 'tb.in'
          results_file    = 'tb.out'