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NEOS Interfaces to BARON

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The NEOS Server offers BARON for the solution of global optimization problems in 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 its 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 is developed 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 (CPLEX and MINOS are the default BARON solvers for LP and NLP subproblems, respectively).

Using the NEOS Server for BARON

The user must submit a model in GAMS format to solve a global 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 must not execute external program, i.e., no $call or execute statements.
  • It must not create files, i.e. no put files or $echo statements.
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 and an alphabetical index is also available.

The NEOS Server initially 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 the modeling language for further information.

To submit a global optimization problem specified in the GAMS modeling language, you need to specify the absolute path to a GAMS file on your system.
Model File:

The Options file is optional and requires that the statement <modelname>.optfile = 1 ; exist before the solve statement in your model file. Only optfile = 1 is supported, however, options also may be specified within the model input file (see the GAMS documentation).

Options File:

The GDX file is an optional file for inputs. It will be renamed in.gdx. The model must include "$GDXIN in.gdx" to load this file.
GDX File:

If the box is checked, the solver will return a compressed GDX file that contains all symbols in the model.
Return GDX output:

If the box is checked, the log file containing information generated by the solver will be returned with the output.
Return log file:

You may enter any additional comments here, for example, to identify the data for your own information. These comments will be returned with your results.

Dry run: generate job XML instead of submitting it to NEOS
Short Priority: submit to higher priority queue with maximum CPU time of 5 minutes
e-mail address:

By submitting a job, you have accepted the Terms of Use
Please do not click the 'Submit to NEOS' button more than once.

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