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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 can be found in the LOQO User's Manual (Version 4.05).

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

Using the NEOS Server for LOQO

The user must submit a model in AMPL format to solve a nonlinearly constrained optimization problem. Sample models in the AMPL format can be found in the netlib collection.

The model is specified by a model file, and optionally, a data file and a commands file. If the command file is specified it must contain the AMPL solve command.

The commands file can contain any AMPL command or set options for LOQO with, for example,
option loqo_options "maxit=50 epssol=10e-05";
Printing directed to standard out is returned to the user with the output.
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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