Dakota Reference Manual: variable_neighborhood_search

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variable_neighborhood_search

Percentage of evaluations to do to escape local minima.

## Specification

Alias: none

Argument(s): REAL

Default: 0.0

## Description

The `variable_neighborhood_search` keyword is used to set the percentage (in decimal form) of function evaluations used to escape local minima. The mesh adaptive direct search method will try to perform a maximum of that percentage of the function evaluations within this more extensive search.

Default Behavior

By default, `variable_neighborhood_search` is not used.

Usage Tips

Using `variable_neighborhood_search` results in an increased number of function evaluations. If the desired result is a local minimum, the added cost is of little or no value, so the recommendation is not to use it. If the desired result is the best local minimum possible within a computational budget, then there is value in setting this parameter. Note that the higher the value, the greater the computational cost. The value should be no greater than 1.0.

## Examples

The following example shows the syntax used to set `variable_neighborhood_search`.

    method
      mesh_adaptive_search
        seed = 1234
        variable_neighborhood_search = 0.1