Dakota Reference Manual: uniform_uncertain

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uniform_uncertain

Aleatory uncertain variable - uniform

## Topics

This keyword is related to the topics:

- continuous_variables
- aleatory_uncertain_variables

## Specification

Alias: none

Argument(s): INTEGER

Default: no uniform uncertain variables

Child Keywords:

| Required/Optional | Description of Group | Dakota Keyword | Dakota Keyword Description
--- | --- | --- | --- | ---
| Required | lower_bounds | Specify minimum values
| Required | upper_bounds | Specify maximium values
| Optional | initial_point | Initial values for variables
| Optional | descriptors | Labels for the variables

## Description

The number of uniform uncertain variables and their distribution lower and upper bounds are required specifications, while variable descriptors is an optional specification. The uniform distribution has the density function:

where and are the upper and lower bounds of the uniform distribution, respectively. The mean of the uniform distribution is and the variance is .

## Theory

This distribution is a special case of the more general beta distribution.

For some methods, including vector and centered parameter studies, an initial point is needed for the uncertain variables. When not given explicitly, these variables are initialized to their means.