Introduction to Sunsort

The aim of the Sunsort package is to provide software to replay event-by-event data produced during Charissa experiments.

The design goals which were used to frame the evolution of this package were:

• Provide as `user friendly' a package as possible.
• Attempt to exploit the benefits of the UNIX programming environment.
• Modularise the tasks required of the package into several distinct objects.
• Reduce the overheads involved in producing a working sorting process.
• Incorporate other useful physics programs directly into the reduction package, for example, the fast fitting routine BUFFIT written by N.M. Clarke.
• Maintain backward compatibility with S.J. Bennett's earlier version of Sunsort.

Sunsort in its present incarnation is made up of several cooperative processes which interact with one another through various UNIX IPCs.

At the heart of the Sunsort package is a library of C functions which provides the user with facilities to access data from one of four possible sources (disk, exabyte, Ethernet or the DEMON DA system) and to decode this data into a simple array of ADC values. A user provided FORTRAN or C subroutine is linked to this library to form the core sort process. During sorting, the user's subroutine is called once per event and is passed the array containing the ADC values. The user, through his/her coding of this subroutine, is therefore left to decide how to manipulate the experimental data. Within the subroutine the user can call upon various Sunsort library utility routines in order to, almost other things, increment spectra, perform windowing operations and filter selected events back to a storage medium.