Dakota Reference Manual: triangular_uncertain

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triangular_uncertain

Aleatory uncertain variable - triangular

## Topics

This keyword is related to the topics:

- continuous_variables
- aleatory_uncertain_variables

## Specification

Alias: none

Argument(s): INTEGER

Default: no triangular uncertain variables

Child Keywords:

| Required/Optional | Description of Group | Dakota Keyword | Dakota Keyword Description
--- | --- | --- | --- | ---
| Required | modes | Distribution parameter
| 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 triangular distribution is often used when one does not have much data or information, but does have an estimate of the most likely value and the lower and upper bounds. The number of triangular uncertain variables, the modes, and the distribution lower and upper bounds are required specifications, whilevariable descriptors is an optional specification.

The density function for the triangular distribution is:

if , and

if , and 0 elsewhere. In these equations, is the lower bound, is the upper bound, and is the mode of the triangular distribution.