User Library Functions

DPL provides an extensive modeling environment and, with links to other applications, has almost everything you need to complete your decision problem model. In some cases, however, you may need to do something that DPL cannot do by itself, either because it requires procedural control, it requires access to data not available through Excel or OLE, an existing program is too large or complex to rewrite easily in DPL or spreadsheet format, or other environments or languages offer better performance.

In these cases, you need to create a user-defined library which contains the functions or program you wish to run and language that allows the library to communicate with DPL. This user-defined library is a Dynamic Link Library (DLL).

To call an external program from within a DPL program, you define a function reference like this:

extprog.main(p1, p2, p3)

extprog - The name of the library (EXTPROG.DLL).

main - The name of a function within the library.

p1, p2, p3 - Parameters for the function. These parameter values may depend on the path through the tree. This argument list may contain strings and may include up to 127 arguments.

A call to an external program is a function, so it will always return a single value after execution.

DPL requires that a user-defined library conform to a number of interface conventions. If you think you may be interested in creating a dynamic link library for use with DPL, contact Technical Support.

Versions: DPL Enterprise, DPL Portfolio