Introduction to the HUGIN ActiveX Server API for Visual Basic

Startpage

The HUGIN API (application programming interface) is a library that allows a programmer to use Bayesian belief networks with both discrete and continuous variables and influence diagrams in their own applications. It is used as a library where the programmer invokes API functions from the application program whenever the application wants to have belief network operations performed. This enforces a strong layering between the application program and the HUGIN API. Typically the application program handles a graphical user interface - e.g the HUGIN tool is built upon the HUGIN API.

Figure 1: Strong layering between the application program and the HUGIN API. The arrow indicates the direction of function invocation between the layers.

Previously the HUGIN API came only as a C library, but by creating a Visual Basic ActiveX server it is possible to use the API when creating a Visual Basic application. Besides simply supporting Bbn programming in yet another language, the Visual Basic interface enables the interaction between Bbns and applications such as Microsoft Word, Excel or Access. E.g you can use Excel to calculate the probability tables for the nodes in your network or extract evidence from patient records stored in Access.

Programming the HUGIN API ActiveX Server in Visual Basic

To help you get started programming the HUGIN API ActiveX Server, a lightweight tutorial containing two small examples has been written. One illustrates how one would use Visual Basic as just another language to program Bbn applications while the other shows how to exploit the many potential possibilities by integrating with Excel.

As you move on, you can find information about all the classes modules, properties, subs, functions etc. of the API in the API reference manual.

In case you discover a bug og have some comments about the ActiveX Server please send an email to activex@hugin.com.


HUGIN Expert A/S, 2008 - comments to activex@hugin.com