Execute an OpenDX program.
file_prefix: The file name prefix. For example if file is set to `temp', then the OpenDX program temp.net will be loaded.
dir: The directory to change to for running OpenDX. If this is set to None, OpenDX will be run in the current directory.
dx_exe: The OpenDX executable file.
vp_exec: A flag specifying whether to execute the visual program automatically at start-up. The default of True causes the program to be executed.
This will execute OpenDX to display the space maps created previously by the δx.map user function. This will work for any type of OpenDX map.