COPS: Large-Scale Optimization Problems

We are continuing the development of COPS, a large-scale Constrained Optimization Problem Set. The primary purpose of this collection is to provide difficult test cases for optimization software. Problems in the current version of the collection come from fluid dynamics, population dynamics, optimal design, mesh smoothing, and optimal control.

For each problem we provide a short description of the problem, notes on the formulation of the problem, and results of computational experiments with general optimization solvers. Each problem has been implemented in AMPL. The models from COPS 2.0 are also available in GAMS, courtesy of GAMS Development Corporation.

The current version of the test set are documented in the report

which contains descriptions of the problems, notes on the formulation, graphs of the solutions, and the results of computational experiments. The article discusses the analysis and interpretation of benchmarking data. The MATLAB script perf.m can be used to create performance profiles for MATLAB. The header of the script contains documentation on its use. Michael Friedlander has also written a performance profiling script in Python that uses gnuplot to create encapsulated post-script files. The article examines the importance of optimality measures when benchmarking a set of solvers.

The COPS collection of problems can be obtained by entering your email address below (so that you can be informed of future software updates) and downloading the compressed tar file that contains the AMPL model and data files (Version 3.0) or the compressed tar file of GAMS models (Version 2.0).


COPS: Keeping optimization software honest.

COPS Developers

Alexander Bondarenko
David Bortz
Liz Dolan
Michael Merritt
Jorge Moré
Todd Munson

Related Efforts

Argonne National Laboratory /