NEOS Server Home

NEOS Interfaces to SoPlex80bit

WWW Form & Sample Submissions


The NEOS Server offers SoPlex80bit for the exact solution of linear programming problems. SoPlex is a linear programming solver based on the revised simplex algorithm. Beyond standard floating-point computation it can solve LPs exactly over the rational numbers using a high-level iterative refinement procedure combined with a rational LU factorization and continued fraction approximations.

SoPlex was originally written by Roland Wunderling and is actively developed by the Department of Optimization at Zuse Institute Berlin. The exact functionality is mainly due to Ambros Gleixner and Daniel Steffy.

For added numerical robustness the NEOS installation uses 80bit extended-precision for the floating-point routines. Documentation of the floating-point routines and further information can be found on the SoPlex homepage.

This solver was implemented by Hans Mittelmann and executes at

Using the NEOS Server for SoPlex80bit

The user must submit an LP problem with either rational or real data in either MPS or (CPLEX-) LP format.

The user may submit a modified version of this parameter file to customize settings.

Web Submission Form
SoPlex80bit data (MPS or LP format file)
Enter the complete path to the input file
Parsing mode
Should data be parsed as floating-point numbers or exactly?
Solving mode
In which mode is the problem to be solved?
exact with rational factorization
exact without rational factorization
floating point
User parameter settings
Enter the complete path to the settings file (optional)
Basis file for warmstart (CPLEX format)
Enter the complete path to the basis file (optional)
Additional Settings
Dry run: generate job XML instead of submitting it to NEOS
Short Priority: submit to higher priority queue with maximum CPU time of 5 minutes
E-Mail address:
Please do not click the 'Submit to NEOS' button more than once.