ILOG OPL syntax highlighting for gEdit

This article offers the syntax highlighting definition file for gEdit 2.16.

ILOG OPL cannot distinguish apples from oranges

I used to think about OPL that promotes obligatorily mathematical rigor as one would expect from a mathematical modeling language. I was misunderstood: it seems that OPL deludes itself when comparing apples and oranges. OPL still requires enhancements that address serious idiosyncrasies how the model is handled.

On fixing CPLEX variable names generated by OPL

You wrote your OPL model for your important mathematical programming problem. But the result looks weird: the model just cannot produce such solution. The most desperate approach consists in diving though the mathematical programming model generated by OPL, checking each (in)equation one by one.

Here I describe some issues that happened while using the OPL Java interface to create the CPLEX model and to print out the mathematical programming model as a .lp file. And after days of frustration with this .lp printout, I found myself writing my own Java class that renames all CPLEX variables generated by OPL…

OPL and Java: loading dynamic Linux libraries

When calling IBM ILOG OPL (Optimization Programming Language) from a Java application running on Linux, one will face some issues regarding loading dynamic OPL libraries. Typical error messages look like:

Native code library failed to load: ensure the appropriate library (oplXXX.dll/.so) is in your path.

java.lang.UnsatisfiedLinkError: no opl63 in java.library.path
java.lang.UnsatisfiedLinkError: no opl_lang_wrap_cpp in java.library.path
java.lang.UnsatisfiedLinkError: no cp_wrap_cpp_java63 in java.library.path
java.lang.UnsatisfiedLinkError: no concert_wrap_cpp_java63 in java.library.path

This article explains my considerations and some approaches how to fix it.

OPL language: the battle of array declarations

The OPL Development Studio, created by ILOG (and recently acquired by IBM), provides tools based on the Optimization Programming Language. This tool intends to simplify the process of feeding data and model formulae to other ILOG optimization tools for mathematical programming and constraint programming.

Experience has been proven OPL to be extremely helpful as a compact and high level language for both data and model. Nevertheless, this language still reveals some constructs that are not well understood nor well documented.

For example, there are many pitfalls a novice developer will face on OPL while working with arrays. Here, and on subsequente articles, I will share some advices that would have been useful while I learned OPL.