XINPUT: a program to edit "DOSRZ" input files

The DOSRZ user code, which is part of the EGS4 standard distribution, is widely used in medical physics for the calculation of dose deposition in cylindrical geometries. The code provides the use of advanced Monte-Carlo techniques (PRESTA) and variance reduction methods. In the case of complex cylinder geometries the input of coordinates and radii is not only tedious but also prone to a high error rate. Coordinates are to be stated in absolute numbers. A change of one number, e.g., the slab thickness, requires the change of all subsequent numbers. Furthermore, parameters are only stated as numbers with no indication of their meaning. Obviously, there is a need for a user interface to facilitate the input for DOSRZ and to largely reduce the possibility for errors. We, therefore, wrote a graphical user interface (GUI) consisting of an input mask, a coordinate input interpreter, and a two-dimensional and/or pseudo-three-dimensional display section. The GUI is based on the scripting language Tcl/Tk, which runs under various platforms such as UNIX (LINUX), w95, and WIN NT. It consists of a main window which provides common-style menus and buttons to navigate through the edit dialog boxes. The most important tools are the region input, which enables the user to create the simulation geometry, and the graphics section where the scaled output can be displayed. Different media are shown in different colors which are user defined. Furthermore, the program contains some tools to reduce the probability of an erroneous input in the EGS4 input file. Since Tcl/Tk is a modern scripting language, it offers advanced tools to create the GUI and to "glue" different applications to it. XINPUT may also be considered as a model program for the development of a more general interface to other input areas of the EGS4 simulation code.