About

SoPlex is an optimization package for solving linear programming problems (LPs) based on an advanced implementation of the primal and dual revised simplex algorithm. It provides special support for the exact solution of LPs with rational input data. It can be used as a standalone solver reading MPS or LP format files via a command line interface as well as embedded into other programs via a C++ class library. The main features of SoPlex are:

• presolving, scaling, exploitation of sparsity, hot-starting from any regular basis,
• column- and row-oriented form of the simplex algorithm,
• an object-oriented software design written in C++,
• a compile-time option to use 80bit extended ("quad") precision for numerically difficult LPs,
• an LP iterative refinement procedure to compute high-precision solution, and
• routines for an exact rational LU factorization and continued fraction approximations in order to compute exact solutions.

SoPlex has been used in numerous research and industry projects and is the standard LP solver linked to the mixed-integer nonlinear programming and constraint integer programming solver SCIP.

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License

Since November 4, SoPlex is licensed under the Apache 2.0 License.

Releases up to and including Version 6.0.2 remain under the ZIB Academic License as indicated by the files contained in the releases. The new license applies from Version 6.0.3 onwards.

Any publication for which SoPlex is used must include an acknowledgement and a reference to one of the following articles, depending on the version used:

The SCIP Optimization Suite 7.0
Gerald Gamrath, Daniel Anderson, Ksenia Bestuzheva, Wei-Kun Chen, Leon Eifler, Maxim Gasse, Patrick Gemander, Ambros Gleixner, Leona Gottwald, Katrin Halbig, Gregor Hendel, Christopher Hojny, Thorsten Koch, Pierre Le Bodic, Stephen J. Maher, Frederic Matter, Matthias Miltenberger, Erik Mühmer, Benjamin Müller, Marc E. Pfetsch, Franziska Schlösser, Felipe Serrano, Shinano Yuji, Christine Tawfik, Stefan Vigerske, Fabian Wegscheider, Dieter Weninger, Jakob Witzig
Available at Optimization Online and as ZIB-Report 20-10, March 2020
BibTeX

The SCIP Optimization Suite 6.0
Ambros Gleixner, Michael Bastubbe, Leon Eifler, Tristan Gally, Gerald Gamrath, Robert Lion Gottwald, Gregor Hendel, Christopher Hojny, Thorsten Koch, Marco E. Lübbecke, Stephen J. Maher, Matthias Miltenberger, Benjamin Müller, Marc E. Pfetsch, Christian Puchert, Daniel Rehfeldt, Franziska Schlösser, Christoph Schubert, Felipe Serrano, Yuji Shinano, Jan Merlin Viernickel, Matthias Walter, Fabian Wegscheider, Jonas T. Witt, Jakob Witzig
Available at Optimization Online and as ZIB-Report 18-26, July 2018
BibTeX

The SCIP Optimization Suite 5.0
Ambros Gleixner, Leon Eifler, Tristan Gally, Gerald Gamrath, Patrick Gemander, Robert Lion Gottwald, Gregor Hendel, Christopher Hojny, Thorsten Koch, Matthias Miltenberger, Benjamin Müller, Marc E. Pfetsch, Christian Puchert, Daniel Rehfeldt, Franziska Schlösser, Felipe Serrano, Yuji Shinano, Jan Merlin Viernickel, Stefan Vigerske, Dieter Weninger, Jonas T. Witt, Jakob Witzig
ZIB-Report 17-61, Zuse Institute Berlin, December 2017
Bibtex

The SCIP Optimization Suite 4.0
Stephen J. Maher, Tobias Fischer, Tristan Gally, Gerald Gamrath, Ambros Gleixner, Robert Lion Gottwald, Gregor Hendel, Thorsten Koch, Marco E. Lübbecke, Matthias Miltenberger, Benjamin Müller, Marc E. Pfetsch, Christian Puchert, Daniel Rehfeldt, Sebastian Schenker, Robert Schwarz, Felipe Serrano, Yuji Shinano, Dieter Weninger, Jonas T. Witt, Jakob Witzig
ZIB-Report 17-12, Zuse Institute Berlin, March 2017
Bibtex

The SCIP Optimization Suite 3.2
Gerald Gamrath, Tobias Fischer, Tristan Gally, Ambros M. Gleixner, Gregor Hendel, Thorsten Koch, Stephen J. Maher, Matthias Miltenberger, Benjamin Müller, Marc E. Pfetsch, Christian Puchert, Daniel Rehfeldt, Sebastian Schenker, Robert Schwarz, Felipe Serrano, Yuji Shinano, Stefan Vigerske, Dieter Weninger, Michael Winkler, Jonas T. Witt, Jakob Witzig
ZIB-Report 15-60, Zuse Institute Berlin, February 2016
Bibtex

If you use SoPlex as an exact rational LP solver, please cite the references

Iterative Refinement for Linear Programming
Ambros M. Gleixner, Daniel E. Steffy, Kati Wolter
INFORMS Journal on Computing 28(3):449-464, 2016,
preprint available as ZIB-Report 15-15

Linear programming using limited-precision oracles
Ambros M. Gleixner, Daniel E. Steffy
Math. Program. 183, 525–554, 2020,
preprint available as ZIB-Report 19-57

Combining Precision Boosting with LP Iterative Refinement for Exact Linear Optimization
Leon Eifler, Jules Nicolas-Thouvenin, Ambros M. Gleixner
under review, preprint available as ZIB-Report 23-26

Download

The source code of soplex is available on github. The releases are also available as tarballs. The files you can download there come without warranty. Use at your own risk!

If you use conda, you can install soplex using the conda packages.

Platforms

SoPlex is implemented in C++. The code should be compliant with the current ANSI standard. With a modern C++ compiler you should be able to compile the code on any platform.

More details can be found in the Doxygen documentation.

SoPlex is also available on the NEOS Server, where you can post your model in LP or MPS format to solve it.

Contact

For questions about SoPlex or to report a bug, please write to the SoPlex mailing list soplex@zib.de after subscribing to it at the SoPlex mailing list page.

Developers

Main developers

Further and former developers

Contributors

Cooperation

SoPlex is developed in cooperation with

Imprint and privacy statement

© 2024 by Zuse Institute Berlin (ZIB). For the imprint and privacy statement we refer to the Imprint of ZIB with the following additions and modifications:

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The sharing and storage of this information is necessary due to the contract between ZIB and I2DAMO GmbH that allows I2DAMO GmbH to issue commercial SoPlex licenses. Furthermore the number of SoPlex downloads is tracked and used to generate statistics about the downloads and to generate the world map of download locations. The personal information is used to distinguish the number of downloads from the number of users per year, that might download more than one version or archive. In addition to the privacy statements of ZIB and I2DAMO GmbH we hereby declare that your name and affiliation recorded for the SoPlex download

• is shared with I2DAMO GmbH in this context.
• is used for purposes of granting licenses and for statistics about software downloads.
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