# Variables

Variables are parameters that help to create easily adjustable models such as the investigation of structures with varying geometry.

Variables are parameters that help to create easily adjustable models such as the investigation of structures with varying geometry.

**Symbolic Variables**

Symbolic variables can contain expressions to calculate specific parameters of the model and have specific syntax requirements.**Variable Editor**

The # card presents a list of supported functions and operations. Use this card to calculate the value of the variable as it would be evaluated by PREFEKO at this point.**Arrays**

Arrays provide functionality to allocate a series of numbers to a parameter.**Predefined Variables**

The PREFEKO language includes a number of predefined variables. Generally, these variables remain constant but may be overwritten by re-assignments.**Logical and Mathematical Operators**

Logical operations are supported and a specific order of precedence is followed.**Mathematical Functions**

Various trigonometric, Bessel and miscellaneous functions are built into Feko to help construct geometry, expressions and calculate parameters.