Nonlinear Optimization Models

The subdirectories below marked "gif" contain graphical 2-D depictions of the optimal solution. Those marked "vrml" have links to 3-D virtual reality models depicting the solutions. And those marked "wav" have audio snippets.

Some models (such as cute/hs06[89].mod and jeffc/antenna/*bessel*.mod) require nonlinear functions that are not included with ampl (such as the error function erf() and some Bessel functions). To run these models you need to download funcadd.c, compile it into a dll called amplfunc.dll, and set the shell environment variable AMPLFUNC to point to the directory containing this dll. Here's a sample makefile for building amplfunc.dll on an SGI machine: makefile.irix. For more information, see

Most of the models above have been ``ported'' to GAMS by Andre Savitsky ( and posted to the following gamsworld website: