GAMS: Modeling and Optimization Software
The General Algebraic Modeling System (GAMS release 2.25) is a software system designed for modeling linear, nonlinear and mixed integer optimization problems. The system, available on Strauss and Mahler, is especially useful for large complex models. GAMS allows you to model problems in a highly compact and natural way. After formulating the model, you can easily invoke several solvers to determine the solution to the problem. GAMS also provides an easytouse report writer to display the results of the solver in a useful format. At the University of Delaware, you can use any of three solvers:
 BDMLP: a builtin linear
programming solver
 MINOS: the widelyused Modular Incore Nonlinear Optimization System
 ZOOM: an integrated ZeroOne Optimization Method and XMP implementation for solving mixedinteger problems.
How to Run GAMS
 Construct a GAMS model by typing the GAMS commands into a file having the filename extension ".gms". For example, a transportation model might be stored in a file named transport.gms. The library of online sample models is described in a subsequent section.
 To run GAMS on this model,
type:
gams filename
where "filename" is replaced by the name of the file without the .gms extension. For the transport.gms example, type:
gams transport
 The output file will have the
extension ".lst". For the transport.gms
example, the output file is named
transport.lst.
(The "gams" command is stored in the directory /opt/bin.)
The GAMS Sample Model Library
The GAMS documentation describes approximately 100 models that serve as examples of simple and complex linear, nonlinear, and mixed integer formulations. These are stored online and can be copied and modified if you know either the name or the reference number of the model. For example, there is a blending problem known by the name "blend" and the reference number 47, in the GAMS printed documentation. To copy this model to your current working directory, type either of the following:
gamslib blendor
gamslib 47(The "gamslib" command is stored in the directory "/opt/bin".)
Additional Documentation
 The online documentation is in the
directory /opt/lib/gams/doc.

gamsinfo is a general
introduction to the package.

gams.doc is a complete
description of the commands and
optional keywords that can be
used on the command line or in
the command file.

gamsparm.doc is a list of
GAMS parameters that can be used
on the GAMS command line or
included in the
GAMSPARM.TXT file to
customize the default values for
GAMS.

gamsinfo is a general
introduction to the package.
 To obtain online help, type:
gams h
 Before using the "man gams" command
to view the man pages, you must first
add the following command to your
.localenv file.
setenv MANPATH ${MANPATH}:/opt/lib/gams/doc/man
The .localenv file is a special configuration file (dotfile) like .cshrc and .login that is stored in your home directory.
 The manual for the package is "GAMS: A User's Guide", by A. Brooke and A. Meeraus. It is available from the University Bookstore and the Client Support & Services Reference Library (in the RDMS Lab, Smith Hall).