NEOS Interfaces to feaspump

Sample Submissions


The NEOS Server offers FEASPUMP2 for the solution of mixed-integer linear feasibility problems in AMPL format.

The feasibility pump (FP) algorithm was originally developed by Fischetti, Glover, and Lodi for finding feasible points of binary LPs. It was then generalized to mixed-integer LPs by Bertacco, Fischetti, and Lodi ("BFL"). Achterberg and Berthold ("AB"; ZIB Berlin) developed this algorithm further. FEASPUMP2 is a further development of both variants by Fischetti and Salvagnin. FP2 uses the CPLEX library.

This solver was implemented by Hans Mittelmann and runs at under

Using the NEOS Server for FEASPUMP2

The user must submit a mixed-integer linear programming problem in AMPL format. Examples of models in AMPL format can be found in the MIPLIB 2003 library.

Only a model and a datafile may be submitted no command file. The reason is that an MPS file is produced from the AMPL model and a file is put out that shows the correspondence of the variable names in the AMPL script and the MPS file respectively.
Note: Do not use an "end" at the end of the model file!

The administrator of FEASPUMP reserves the right to keep and use problem instances submitted through NEOS for testing and debugging purposes.

Using the NEOS Server for feaspump/AMPL

The user must submit a model in AMPL format. Examples are provided in the examples section of the AMPL website.

The problem must be specified in a model file. A data file and commands files may also be provided. If the commands file is specified, it must contain the AMPL solve command; however, it must not contain the model or data commands. The model and data files are renamed internally by NEOS.

The commands file may include option settings for the solver. To specify solver options, add

  option feaspump_options 'OPTIONS';
where OPTIONS is a list of one or more of the available solver options for AMPL.

Web Submission Form
AMPL model
Enter the complete path to the AMPL model file (linear, minimization, no commands, no "end")
AMPL data
Enter the complete path to the AMPL data file (optional, no commands)
FP version
Choose the FP version (ab, bfl)

Additional Settings

E-Mail address:
Please do not click the 'Submit to NEOS' button more than once.