BARON

The NEOS Server offers BARON for the solution of mixed integer nonlinearly constrained optimization problems and global optimization problems. Problems for BARON can be submitted on NEOS in AMPL or GAMS format.

BARON is a computational system for solving nonconvex optimization problems to global optimality. Purely continuous, purely integer, and mixed-integer nonlinear problems can be solved with the software. The Branch And Reduce Optimization Navigator derives its name from combining constraint propagation, interval analysis, and duality in its reduce arsenal with enhanced branch and bound concepts as it winds its way through the hills and valleys of complex optimization problems in search of global solutions.

BARON was developed and is currently maintained by Nick Sahinidis.

Availability of BARON on the NEOS Server is possible thanks to the generosity of The GAMS Development Corporation and the providers of software for the solution of the LP and NLP subproblems solved by BARON.

Using the NEOS Server for BARON/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:

• It must be self contained, i.e., no $include or $batinclude statements.
• It may not execute external programs, i.e., no $call or execute statements.
• No file creation, i.e. no put files or $echo except for a file named 'results.txt'. Other files created in the GAMS model file will be deleted.

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.

Please see the GAMS/BARON webpage for more information.