NEOS Server Home

NEOS Interfaces to Bonmin

Sample Submissions
WWW Form - Email - XML-RPC


The NEOS Server offers Bonmin (Basic Open-source Nonlinear Mixed INteger programming) for the solution of mixed-integer nonlinearly-constrained optimization problems. Bonmin is also available open source under the Common Public License. Problems for Bonmin can be submitted on the NEOS server in AMPL or GAMS format.

Bonmin is an experimental open-source C++ code for solving general mixed-integer nonlinearly constrained problems. Bonmin features several algorithms

The algorithms in Bonmin are exact when the objective and constraint functions are convex; in the case the functions are non-convex, they are heuristics.

Bonmin is a hybrid between two classical algorithms for mixed-integer nonlinear programming: an outer-approximation-based branch-and-cut-based algorithm and a pure branch-and-bound algorithm. The user can set options to declare which version of the algorithm should be employed through NEOS.

Bonmin was developed by a large team of researchers at IBM and Carnegie Mellon:

Information about Bonmin can be found on the Bonmin homepage on the COIN-OR website.

Using the NEOS Server for Bonmin/GAMS

The user must submit a model in GAMS format to solve an optimization problem. For security purposes, the model submitted must adhere to the following conventions:

If you are unfamiliar with GAMS, the GAMS Documentation includes a GAMS Tutorial and User's Guide. Examples of models in GAMS format can be found in the GAMS model library.

By default, the NEOS Server limits the amount of output generated in the listing file by turning off the symbol and unique element list, symbol cross references, and restricting the rows and columns listed to zero. This behavior can be changed by specifying the appropriate options in the model file. See the documentation on GAMS output for further information.

You may optionally submit an options file if you wish to override the default parameter settings for the solver. Currently, the NEOS Server can only use optfile=1 with GAMS input. Therefore, any model that specifies a different options file will not work as intended.

Documentation for GAMS/CoinBonmin is available in PDF format.

Web Submission Form
Model File
You can submit an optimization problem specified in the GAMS modeling language to be solved using the optimization tools on the NEOS Server. You need to specify the absolute path to a GAMS file on your system.
Options File
The Options file is optional and requires that the statement <modelname>.optfile = 1 ; exist before the solve statement in your model file. At this time, only optfile = 1 is supported; however, options may also be specified within the model input file (see the GAMS documentation).
GDX File
Optional GDX file for inputs. This file will be renamed to in.gdx. The model must include "$GDXIN in.gdx" to load this file.
Return GDX output
Return log file
Enter any additional comments here (e.g. to identify the data for your own information). These comments will be returned with your results.
Additional Settings

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