# VARIABLE

Expressions are used to define a quantity in terms of variables that are defined using the VARIABLE command or in terms of built in math functions (sin, cos, tan, and so on). The order in which commands appear is not important. Variable x could be a function of variable y, even though it appears afterwards in the input file.

## Syntax

VARIABLE{ parameters}

## Qualifier

This command has no qualifier.

## Parameters

- variable_name (string)
- Given name of the variable
- expression (string)
- Number or mathematical expression that defines this variable
- active_flag (boolean)
- Read and process the command or ignore it

## Example

```
VARIABLE{
variable_name = meanVel
expression = 0.2265
}
VARIABLE{
variable_name = nSeeds
expression = 15
}
```