string

Discrete, epistemic uncertain variable - strings within a set

Topics

discrete_variables, epistemic_uncertain_variables

Specification

• Alias: None

• Arguments: INTEGER

• Default: no discrete uncertain set string variables

Child Keywords:

Required/Optional	Description of Group	Dakota Keyword	Dakota Keyword Description
Optional		elements_per_variable	Number of admissible elements for each set variable
Required		elements	The permissible values for each discrete variable
Optional		set_probabilities	This keyword defines the probabilities for the various elements of discrete sets.
Optional		initial_point	Initial values for variables
Optional		descriptors	Labels for the variables

Description

Discrete set variables may be used to specify categorical choices which are epistemic. For example, if we have three possible forms for a physics model (model 1, 2, or 3) and there is epistemic uncertainty about which one is correct, a discrete uncertain set may be used to represent this type of uncertainty.

This variable is defined by a set of strings, in which the discrete value may take any value within the string set (for example, the set may be defined as ‘coarse’, ‘medium’, and ‘fine’)

Other epistemic types include:

• variables-continuous_interval_uncertain

• variables-discrete_interval_uncertain

• discrete_uncertain_set variables-discrete_uncertain_set-integer

• discrete_uncertain_set variables-discrete_uncertain_set-real

Examples

discrete_uncertain_set
 string
 num_set_values 2             3
 set_values     'red' 'blue'  'coarse' 'medium' 'fine'
 descriptors    'ds1'         'ds2'