COPS: Large-Scale Optimization Problems

We are continuing the development of COPS, a collection of large-scale Constrained Optimization ProblemS. 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, 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. We currently have results for LANCELOT, MINOS, SNOPT, and LOQO.

Each problem has been implemented in AMPL and (courtesy of GAMS Development Corp.) in GAMS. The report

Benchmarking Optimization Software with COPS, Mathematics and Computer Science Division, Argonne National Laboratory, Technical Report ANL/MCS-246, November 2000 (Revised December 20), Postscript version

contains descriptions of the problems, notes on the formulation, graphs of the solutions, and the results of computational experiments. The article

Benchmarking Optimization Software with Performance Profiles, Mathematics and Computer Science Division, Argonne National Laboratory, Preprint ANL/MCS-P861-1200, January 2001, Postscript version

discusses the analysis and interpretation of benchmarking data. The companion Perl script, perf.pl, 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 current collection (Version 2.0) of COPS 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 or the compressed tar file of GAMS models.

COPS: Keeping optimization software honest.

COPS Developers

Michael Merritt

Benchmarking Report (HTML version)
Electrons on a Sphere	Flow in a Channel	Goddard Rocket
Hang Glider	Hanging Chain	Isometrization of Alpha-Pinene
Largest Small Polygon	Linear Tangent Particle Steering	Marine Population Dynamics
Non-inertial Robot Arm		Optimal Cam Shape
Elastic Plastic Torsion	Pressure Distribution in Journal Bearing	Minimal Surface with Obstacle
Catalytic Cracking of Gas Oil	Methanol to Hydrocarbons	Catalyst Mixing

Other Benchmarks

Benchmarks for optimization software.
- Including: DONLP2 on COPS 2.0
MINOS, LANCELOT, and LOQO with the Vanderbei problems.
LANCELOT and MINOS with the CUTE problems.

Argonne National Laboratory / more@mcs.anl.gov