Dakota Reference Manual: centered_parameter_study

| Dakota Reference Manual Version 6.15 Explore and Predict with Confidence

- Main Page
- Related Pages

All Pages
centered_parameter_study

Samples variables along points moving out from a center point

## Topics

This keyword is related to the topics:

- parameter_studies

## Specification

Alias: none

Argument(s): none

Child Keywords:

| Required/Optional | Description of Group | Dakota Keyword | Dakota Keyword Description
--- | --- | --- | --- | ---
| Required | step_vector | Size of steps to be taken in each dimension of a centered parameter study
| Required | steps_per_variable | Number of steps to take in each dimension of a centered parameter study
| Optional | model_pointer | Identifier for model block to be used by a method

## Description

Dakota's centered parameter study computes response data sets along multiple coordinate-based vectors, one per parameter, centered about the initial values from the variables specification. This is useful for investigation of function contours with respect to each parameter individually in the vicinity of a specific point (e.g., post-optimality analysis for verification of a minimum), thereby avoiding the cost associated with a multidimensional grid.

Default Behavior

By default, the centered parameter study operates over all types of variables.

The `centered_parameter_study` takes steps along each orthogonal dimension. Each dimension is treated independently. The number of steps are taken in each direction, so that the total number of points in the parameter study is .

Expected Outputs

A centered parameter study produces a set of responses for each parameter set that is generated.

Expected HDF5 Output

If Dakota was built with HDF5 support and run with the hdf5 keyword, this method writes the following results to HDF5:

- Parameter Sets
- Variable Slices

## Examples

The following example is a good comparison to the examples on multidim_parameter_study and vector_parameter_study.

    # tested on Dakota 6.0 on 140501
    environment
      tabular_data
        tabular_data_file = 'rosen_centered.dat'

    method
      centered_parameter_study
        steps_per_variable = 5 4
        step_vector = 0.4 0.5

    model
      single

    variables
      continuous_design = 2
        initial_point =   0        0
        descriptors =     'x1'     "x2"

    interface
      analysis_driver = 'rosenbrock'
        fork

    responses
      response_functions = 1
      no_gradients
      no_hessians

## See Also

These keywords may also be of interest:

- multidim_parameter_study
- list_parameter_study
- vector_parameter_study