TWIST MOFIA MANUAL

Introduction

The framework of MOFIA has been adapted from KOFIA, the software
package developed for BNL experiment E787. The first version, MOFIA
1.0 contains the code used to analyze the test data acquired with 5
x-planes and 2 y-planes in the test run of August 1997. MOFIA 1.0
contains a full software analysis package of this test data,
including: calibrations, efficiency and tracking. The second version,
MOFIA 1.5, includes a "skeleton" that would allow the user to access
the Monte Carlo data for purposes of developing the remaining software
packages for TWIST. Both MOFIA 1.0 and MOFIA 1.5 are written in
FORTRAN 77. Since then the collaboration have decided to adopt a more
modern language, FORTRAN 90, due to many attractive features in this
language. This lead to the development of MOFIA 2.0. Since FORTRAN 90
compilers are able to compile FORTRAN 77 code, we decided to keep as
much as we can of the MOFIA main framework code (the code adapted from
E787) in FORTRAN 77. This was mainly done for two reasons: first, the
code adapted from E787 is well written and tested so that changing it
will unnecessarily consume too much manpower; and second,
compatibility with E787 is desired since it will allow us to benefit
from E787 modifications to the code. For the same reasons, we decided
not to modify any of the other packages that we adapted, namely: CFM,
YBOS, GPLOT, BRU and CERN libraries. On the ALPHA, these packages are
compiled using the f77 compiler. On LINUX, however, it was necessary
to recompile them with f90, due to incompatibilities between our
compiler of choice for LINUX f90, ABSOFT, and the g77 compiler. Only
minor changes, however, were made to these packages.

All the TWIST code written for MOFIA 1.5 was completely rewritten and
reorganized in MOFIA 2.0 in order to utilize the nice features of
FORTRAN 90, including the data structures. MOFIA 2.0 also includes the
geometry structures and the TDC unpacking for the proportional
chambers. In addition, MOFIA 2.0 is capable of analyzing the test data
of August 1999, for the UV prototype chamber pair. This last feature
allowed us to test MOFIA 2.0 with real data and compare directly the
results from MOFIA 2.0 and MOFIA 1.5. While the collaboration has
initially decided to support four computer platforms, only the LINUX
and ALPHA platforms have been used since the release of MOFIA
2.0. While the TWIST cluster will consist entirely of LINUX boxes, the
continuing support of the ALPHA platform is considered beneficial
since it might reveal code (or even compiler) bugs that may otherwise
go undetected by the LINUX ABSOFT compiler. MOFIA 2.0 has been tested
on ALPHA and LINUX, and the analysis results from both Monte Carlo and
real data were identical.

Since then another version, MOFIA 2.1, has been released but the MOFIA
2.0 manual has not been updated to reflect the modifications in that
version. This manual will be entirely focused on the current version,
MOFIA 2.2.

In the discussion below, some knowledge of FORTRAN 90 is assumed. We
found that the book "Upgrading to FORTRAN 90" by Cooper Redwine
provides a good introduction to FORTRAN 90, at least for those
familiar with FORTRAN 77. Specific documents for the ALPHA and the
ABSOFT compilers and debuggers are also useful references. For ABSOFT,
this documentation may be found on any machine where ABSOFT is
installed in the directory /usr/absoft/doc. In particular, the file
FxUserGuide.pdf provides information on the ABSOFT Fx multi-language
debugger, and the file F90_Reference.pdf provides information on the
FORTRAN 90 compiler. Information on our debugger of choice for the
ALPHA, ladebug, is on the web at

http://www.compaq.com/products/software/ladebug

and information on DEC FORTRAN 90 is at

http://www.triumf.ca/internal/internal-links/df90/dfau.htm