# DESIGN VARIABLE

Specifies design optimization variables.

## Type

AcuSolve Command

## Syntax

DESIGN_VARIABLE {parameters}

## Qualifier

This command has no qualifier.

## Parameters

- initial_value (real) [=0.0]
- Initial value assigned to the design variable.
- lower_bound (real) [=-1.0]
- Lower bound of design variable.
- upper_bound (real) [=1.0]
- Upper bound of design variable.
- max_update_factor (real) [=0.05]
- Max relative step change allowed for the design variable to change between iterations. The max update factor is relative to the upper_bound and the lower_bound difference.
- supervised_training (array) [={1.0}]
- Manual supervised training is used as input data to create a so called response surface. The corresponding response function values are computed by AcuSolve for the given input training data. The response surface is constructed using a Gaussian Process, which essentially is a function approximating the response values as a function of the design variables.

## Description

The shape of the deformed geometry is controlled by design variable commands. For
each variable a specified shape is defined, for example using mesh displacements
defined in a nodal boundary condition command. Design variables may also control
parameters by using multiplier functions of type set to
design_variable.

```
DESIGN_VARIABLE(“DV1”) {
initial_value = 0.0
lower_bound = -1.0
upper_bound = 1.0
max_update_factor = 0.05
supervised_training = {0.1,0.2,0.5,…. }
}
```