Using equations defined by external programs

GAMS permits one to supply model constraint equations using an external custom written program.  Here I will introduce the topic but note that there are a number of programming issues that are beyond the scope of this manual.  Users wishing more details should consult the source document on the GAMS web site called External Functions that is located at http://www.gams.com/docs/extfunc.htm plus the example and explanation in the document Interfacing GAMS with other applications at http://www.gams.com/~erwin/interface/interface.html

Identifying the equations and their contents: =X=

Building the external function evaluator