Forword

The General Algebraic Modeling System (GAMS) is a high-level modeling system for mathematical programming problems. This document is a guide to GAMS language elements.  The coverage in this document is as complete as possible for developments up to GAMS release 22.7.  GAMS generated information on subsequent releases can be found on http://www.gams.com/docs/release/release.htm.

The guide is designed to provide a smart document with many hyperlinks.  When you click on those they will move you to related places in the document or open up example GMS files.

The document is organized into the sections identified below; an index is also present.  For those wishing a printable copy it is typically on c:\program files\C:\Program Files\GAMS22.7\docs\bigdocs\gams2002\mccarlgamsuserguide.pdf or here.

The overall contents of the document are as follows

Quick Start Tutorial

Sets

Data Entry

Variables, Equations, Models and Solvers

Model Types and Solvers

Standard Output

Writing Models and Good Modeling Practices

Running Jobs with GAMS and the GAMS IDE

Fixing Compilation Errors

Rules for Item Names, Element Names and Explanatory Text

Including Comments

Calculating Items

Improving Output via Report Writing

Rules for Item Capitalization and Ordering

Conditionals

Control Structures

Doing a Comparative Analysis with GAMS

GAMS Command Line Parameters

Saves and Restarts

Customizing GAMS

Fixing Execution Errors

Scaling GAMS Models

Small to Large: Aid in Development and Debugging

Speeding up GAMS

Memory Use Reduction in GAMS

Including External Files

Dollar Commands

The Option Command

Output via Put Commands

Acronyms

Conditional Compilation

Using GAMS Data Exchange or GDX Files

Links to Other Programs Including Spreadsheets

Controlling GAMS from External Programs

Solver Option Files

Advanced Basis Usage

Mixed Integer, Semi, and SOS Programming

NLP and MCP Model Types

Model Attributes

Application Help: Model Library, Web Sites, Documentation

Many have contributed to this document beyond the authors.  Erwin Kalvelagen wrote visual Basic Macros used in forming the complete document.  Armin Pruessner provided comments and aid in the GDX chapter.  Tony Brooke, David Kenderick, Alex Meeraus and later Ramesh Raman wrote and rewrote the earlier GAMS Users Guide which provided a foundation for this document.  In addition, outside of GAMS Arne Drud of ARKI Consulting provided a number of insightful comments on the NLP chapter helping improve its contents.  Gideon Kruseman of Wageningen University provided several useful comments.  Rich Benjamin of FERC identified a number of errors or unclear sections in the text that we have fixed.  McCarl's many students at Texas A&M and in commercial GAMS classes have also made contributions.