iCOs (Interval COnstraints Solver)


lebbah*essi.fr / ylebbah*yahoo.fr


This site is under construction. I am not sure that I have put everything to make the installation easy. But, if you are interested, don't hesitate to contact me.

What's ICOS ?

ICOS (Interval COnstraints Solver) is a software package for continuous optimization and solving nonlinear and continuous constraints. It is based on constraint programming, interval analysis and global optimization techniques. ICOS handles the standard form AMPL.


AMPL and ipopt solvers




COCONUT optimization benchmarks

COCONUT Satisfiability benchrmarks

How to use ?

  1. Go to the ICOS directory
    1. % cd icos
  2. Test the program by typing:
    1. % icos-clp-? benchs/alkyl.mod C=configurations/2b-borsuk3.cfg A="../ampl" G="logs"
    2. * where "benchs/alkyl.mod" is the optimization problem to solve, "C=configurations/2b-borsuk3.cfg" contains some tuning and parameters of the branch and bound algorithm, "A="../ampl"" fixes the AMPL solver path, and finaly "G="logs"" fixes the path where results will be stored.

Some configuration files

  • Optimization
    • "opt.cfg" is the default configuration file to solve optimization problems.
    • "opt-quad.cfg" uses the Quad-filtering algorithm in the reduction step.
  • Satisfaction
    • "search.cfg" is the default configuration to solve satisfaction problems.
    • "search-quad.cfg" uses the Quad-filtering algorithm in the reduction step.

Some tips

  • Don't forget to put "solve;" at the end of your mod file. (This is justified by the semantics of AMPL ...)


To come soon ...


Many thanks to Claude Michel, Michel Rueher, Olivier Lhomme, Arnold Neumaier and Oleg Shcherbina for many interesting discussions and feedback.