Stand Management Assistant (SMA)

3. Software Tools

The SMA system consists of three types of elements: Tcl (Tool command language) and Tk (a toolkit for X Window System) form a development environment for creating user interfaces. They were developed by Ousterhout (1994) at the University of California, Berkeley, USA, and have gained popularity both in academia/research and businesses with tens of thousands of estimated users (Strand 1994). Tcl is a scripting language for controlling and extending applications. A Tcl script is interpreted during program execution. Tcl structure allows dynamic user interfaces where, for example, the layouts of the windows can react to user input. The windows in SMA change during a session according to what treatments are defined (the number of thinnings, the number of thinning points).

Tcl is available for most unix platforms, VAX/VMS, Macintosh, DOS, MS-Windows, OS/2, AmigaDOS and NeXT.

 The user interface calls FORTRAN language routines for optimization and stand simulation. C language routines could be used as well. The optimization routines are adopted from Osyczka (1984) and they are described in Valsta (1992a and 1992b). The optimization method is a modification of the Hooke and Jeeves' direct search algorithm which is classified as a derivative-free nonlinear programming algorithm

 Stand simulation routines depend on the purpose of the tool. Two case studies are described below. Necessary parameters for optimization and simulation are passed as argument lists to called routines.

 The user interface also calls the visualization routines for two and three dimensional graphs produced by the Khoros system, developed at the University of New Mexico, USA (Rasure and Williams 1991). The Khoros consortium has established a company, Khoral Research, Inc. to continue system development. The next version of the system will be made publicly available in August 1994.

 Graphing information is obtained from disk files and argument lists. Once a graph is formed by Khoros programs, it can be extensively customized with the options provided in the programs. Printing options are also well developed. The Khoros system is available on most unix platforms for mainframe and micro computers.

 

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