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NEOS Interfaces to LOQO

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The NEOS Server offers LOQO for the solution of nonlinearly constrained optimization problems in AMPL format. LOQO is based on an infeasible primal-dual interior-point method and solves both convex and nonconvex optimization problems. Additional information for LOQO is available in the LOQO User's Manual (Version 4.05).

LOQO was developed by Robert J. Vanderbei and Hande Y. Benson.

Using the NEOS Server with LOQO

The user must submit a model in AMPL format to solve a nonlinear problem. Examples of models in AMPL format can be found in the netlib collection.

The nonlinear program 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. It must not contain the model or data commands. The model and data files are renamed internally by NEOS.

The commands file may include AMPL commands or set solver options for LOQO. To specify solver options, add

option loqo_options "OPTIONS";
where OPTIONS is a list of one or more of the LOQO options, which are listed in the LOQO Options for AMPL.

Enter the location of the AMPL model (local file)
Model File:

Enter the location of the AMPL data file (local file)
Data File:

Enter the location of the AMPL commands file (local file)
Commands File:


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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