**Sedona
XPRESSion Evaluator Reference Guide**

**Built-In
Functions**

The XPRESSion Evaluator comes with a powerful set of built-in functions for performing both numerical computations and for array manipulation. Most of these built-in functions are implemented in LabVIEW as primitives, Formula Node functions, or Advanced Analysis VIs. For functions that behave identically in the XPRESSion Evaluator and in LabVIEW, the user will be refered to their LabVIEW documentation for detailed descriptions.

In defining the proper call syntax for XPRESSion Evaluator functions, the following notation will be used:

*FuncName***(***a,
s1 ***[***, s2 ...***])**

where the square brackets ‘[‘ and ‘]’ enclose optional elements. Arguments that begin with an "a" must be array types. Arguments that begin with an "s" must be scalar types. Arguments that begin with any other letter can be of type array or scalar. For example:

*BuiltInFunc***(***a,
s, ***[***, x1 ***[***,
x2***]])**

This denotes a function named *BuiltInFunc*
whose first argument must be an array and whose second argument
must be a scalar. The function can also be passed two optional
arguments, each of which can be scalar or array variables.

The XPRESSion Evaluator employs a powerful type checker to ensure that arguments passed to built-in functions are of the appropriate type, even when those arguments are themselves complex expressions. This checking is done at "compile" time when the Compile Expr VI is executed, so that the user is alerted of any errors before expression calculations are performed.

**Supported Functions**** ****for a listing of built-in functions**