The Tree parameter subsystem was originally developed by Daniel Bazin. It has since been reimplemented and incorporated into SpecTcl. The tree parameter subsystem provides two facilities for SpecTcl parameters and Tcl variables;
The ability to structure parameter space in to more convenient organizations than the flat array that SpecTcl uses internally, as well as to associate metadata with SpecTcl parameters.
The ability to bind Tcl variables to metadata (e.g. units of measurement) and to allow access to those data without the need to understand how to program the Tcl or Tcl++ libraries. This, along with the user interface elements that support tree parameters makes steering computation performed by event pipeline elements much simpler than it otherwise might be.
In this part we will provide reference information for the tree parameter subsystem. This information will be limited to the public interfaces of the classes intended for use by SpecTcl programmers.