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NEOS Interfaces to Couenne

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Couenne

The NEOS Server offers Couenne for the solution of global optimization problems in GAMS format. Couenne solves global optimization problems using a reformulation-based branch-and-bound algorithm for a globally optimum solution. Additional details and options are available in the Couenne user's manual.

Couenne is developed and maintained by Pietro Belotti and others. Visit the Couenne page at COIN-OR for more details.


Using the NEOS Server with Couenne

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 may not execute external programs, i.e., no $call or execute statements.
  • It may 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 Libraries.

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.


Web Submission Form
Model File
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.
Options 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).
GDX 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.
Return GDX output
If the box is checked, the solver will return a compressed GDX file that contains all symbols in the model.
Return log file
If the box is checked, the log file containing information generated by the solver will be returned with the output.
Comments
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.
Additional Settings
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:
Please do not click the 'Submit to NEOS' button more than once.