The NEOS Server offers Bonmin (Basic Open-source
Nonlinear Mixed INteger programming)
for the solution of mixed-integer nonlinearly constrained optimization problems in AMPL format. Bonmin is also
available open source under the
Common Public License.
Bonmin was developed by a large team of researchers at IBM and
- Pierre Bonami
- Lorenz Biegler
- Andrew Conn
- Gerard Cornuejols
- Ignacio Grossmann
- Carl Laird
- Jon Lee
- Andrea Lodi
- Francois Margot
- Nicolas Sawaya
- Andreas Waechter
Information about Bonmin can be found on the Bonmin homepage on
the COIN-OR website. 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.
Using the NEOS Server with Bonmin
The user must submit a model in AMPL
format to solve a mixed-integer nonlinearly constrained optimization problem.
Examples of models in AMPL format are available from the
The mixed-integer nonlinear programming problem must be specified by a
model file with the options of a data file and a commands file.
If the commands file is specified, it must contain the AMPL solve
command. The commands file must not contain the AMPL model
or data commands. The model and data files are renamed internally
Bonmin has a variety of options that can be set to alter the behavior of
the algorithm. The Bonmin User's Manual describes all the solver options available to
the user. There are two ways to set options for Bonmin: