You may want to write a program which controls the Data Explorer Executive. For example, you could write your own user interface, providing a custom "look and feel", and send Data Explorer script language commands to the Data Explorer executive. In this case you would get all of the functionality provided by the executive (cache management, control of execution order, and object management). You could also directly control the Data Explorer User Interface from a separate program, loading and executing visual programs. For example, you may wish to fire up Data Explorer with a "canned" visualization program once a simulation is complete, with parameters within the visual program preset to particular values.
Graphically, both of these are represented by the upper "User Program" in Figure 1, which controls the Data Explorer Executive or User Interface from the user's program. The libDXL.a library (DXLink) provides this functionality, and is discussed in Chapter 17. "DXLink Developer's Toolkit". Examples of DXLink programs can be found in /usr/local/dx/samples/dxlink.
With the functionality provided by SuperviseWindow and SuperviseState (see SuperviseWindow and SuperviseState in IBM Visualization Data Explorer User's Reference), your program does not need the Image tool (which is provided only within the Data Explorer User Interface) in order to provide direct user interaction in the image window. Thus a custom GUI communicating only with the Data Explorer Executive can implement all of the user-interaction provided by the Data Explorer User Interface. Examples of custom direct interactors can be found in /usr/local/dx/samples/supervise; while these examples are demonstrated using the Data Explorer User Interface, there is no necessity that they do so, as all of the modules used in these examples (SuperviseWindow, SuperviseState, and Display, in particular) are available directly from the Data Explorer Executive.