Quick start - Gams

The IDE contains a powerful navigation aid which helps users directly jump from error
messages into the place in the GMS code where the error message occurs as discussed in
the Running Jobs with GAMS and the GAMS IDE chapter.
When multiple errors occur in a single position, GAMS cannot always locate the $ just in
the right spot as that spot may be occupied.
New users may find desirable to reposition the error message locations so the messages
appear just below the error markings as discussed in the Fixing Compilation Errors
chapter.
Here I have only presented a brief introduction to compilation error discovery. The
chapter on Fixing Compilation Errors goes substantially further and covers through
example a number of common error messages received and their causes.
Symbol list and cross reference maps
The next component of the LST file is the symbol list and cross-reference map. These may or
not be present as determined by the default settings of GAMS on your system. In particular,
while these items appear by default when running command line GAMS they are suppressed by
default when running the IDE.
The more useful of these outputs is the symbol list that contains an alphabetical order all the
variables, equations, models and some other categories of GAMS language classifications that I
have not yet discussed along with their optional explanatory text. These output items will not be
further covered in its tutorial but are covered in the Standard Output chapter.
Execution output
The next, usually minor, element of the GAMS LST file is execution report. Typically this will
involve
A report of the time it takes GAMS to execute any statements between the beginning of
the program and the first solve (or in general between solves),
Any user generated displays of data; and
If present, a list of numerical execution errors that arose.
I will not discuss the nature of this output here, as it is typically not a large concern of new users.
Display statements will be discussed later within this tutorial and are discussed in the Improving
Output via Report Writing chapter. Execution errors and their markings are discussed in the
Fixing Execution Errors chapter.
Generation listing
Once GAMS has successfully compiled and executed then any solve statements that are present
Courtesy of B.A. McCarl, October 2002 16