The COIN-OR Branch and Cut (Cbc) solver is an open-source mixed-integer
linear programming solver written in C++. Problems for Cbc can be submitted
on the NEOS server in AMPL, GAMS, or MPS format.
Cbc is intended to be used primarily as a callable library to create
customized branch-and-cut solvers, however, a basic stand-alone executable
is used to solve problems submitted to the NEOS Server.
Cbc utilizes other COIN-OR projects Cgl (Cut Generation Library) to generate
cutting planes and Cpl to solve the linear programs at each node of the tree.
Cbc was developed by John Forrest, now retired from IBM Research. The project
is currently managed by John Forrest and Ted Ralphs.
For more information on Cbc and the COIN-OR initiative, please visit the Cbc COIN-OR website.
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
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.
<modelname>.optfile = 1 ;
optfile = 1