User Defined Functions

You can create and use these types of custom functions in the same manner as the system defined functions provided by iGrafx:

Distribution Function - Takes no arguments, but returns a value statistically distributed over a range or one of the discrete values defined.
Mapping Function - Matches one set of values to another. An argument is passed to the function which maps it to a new value and returns that value.
Visual Basic for Applications - If you check this box for a function named, for example, F1, whenever the expression evaluator needs a result for that function, it fires the FunctionValue event on the Document object. That event takes the name of the function and its argument (if any) as parameters and returns a double value.

The VBA functions and use of iGrafx objects require advanced programming knowledge.

After you define a function, you then describe its behavior, which depends on whether it is a distribution function or a mapping function.