Introduction
        This interactive graphical user interface for  PHOBOS  is a prototype which will likely change a lot during the next year. It was developed during the Mock Data Challenge 1 at BNL in September 1998; its main use was as a batch script combining common functions such as input file opening, detector geometry and so on for a number of "tasks" used to simulate real data analysis on multiple farm processors controlled by HPSS. Its interactive form is designed as a test especially for online monitoring in the "real" runs. It is intended to remain a CINT script, fast enough to handle an event loop but easily edited. This appears to be feasible for reconstruction and lengthy analysis, but it now appears that for data mining/physics analysis the loop may run so fast that at least the event loop part should be compiled. No attempt has been made at complete generality because it is easy to edit, for example to change the names of the "tasks" and the corresponding buttons.

 The interface consists of a general script phat.C which has (editable) user includes such as Mul.h and calls user routines e.g. Mul.C. In its interactive mode it is supported by phatic.C, which puts up the button panels, and phatset.C, which executes some of the button actions. There is a fairly clean separation of GUI functions from phat.C; in principle one could make a ROOT dialog window interface for controls not using X windows (maybe of interest if one is working through a modem). As of 9/17/98 in fact the planned GUI functions using TG*** widgets from (ROOT tutorials) dialogs.C are not implemented; these work in development tests but cause segment violations in combination with phat code. Until this is solved a temporary interface using dialogs via the ROOT script window is used for setting numbers of events etc.

 The "user" scripts e.g. Mul.C and Mul.h are obtained by editing stand-alone scripts into the form of a macro function of a form described in "Rules for generating user scripts" in the main directory. The changes are minimal but care must be taken with the scope of variables.  Other
tasks used in the MDC1 as of 9/17/98 are Vtx.CSpc.C and Spc.h,  and Out.C.   (When you read this we hope Onl.C and perhaps a task (A.T.)  for stopping particles may also have been implemented.)

 This HELP is an illustration of what will become more general help having to do with the analysis routines, with this phat.C-relevant help becoming just one of the subtopics in the general help.

Donald W. McLeod   Professor of Physics    High Energy Heavy Ion
e-mail: mcleod@uic.edu, phone: (312)996-5358, fax: (312)996-9016
surface mail:       D. McLeod, University of Illinois at Chicago
Physics dept. M/C 273  845 W. Taylor St.  Chicago Il  60607-7059