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The NEOS Server offers MINOS for the solution of nonlinearly constrained optimization problems in AMPL format. MINOS is suitable for large constrained problems with a linear or nonlinear objective function and a mixture of linear and nonlinear constraints. It is most efficient if the constraints are linear and there are not too many degrees of freedom (say up to 1000).

For linear programs, MINOS uses a stable implementation of the primal simplex method. (Basis factors are maintained by LUSOL, a sparse LU package with Markowitz factorizations and Bartels-Golub updating.) For linearly constrained problems, a reduced-gradient method is employed with quasi-Newton approximations to the reduced Hessian. For nonlinear constraints, MINOS implements an SLC (sequential linearly constrained) algorithm derived from Robinson's method. Steplength control is heuristic (for want of a suitable merit function), but superlinear convergence is often achieved. Additional information on MINOS can be found in the AMPL/MINOS User's Guide.

MINOS was developed by Bruce A. Murtagh and Michael Saunders.

Using the NEOS Server for MINOS

The user must submit a model in AMPL format to solve a nonlinearly constrained optimization problem. Examples of models in 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 MINOS with, for example,
option minos_options "timing=3 outlev=2";
Printing directed to standard out is returned to the user with the output.

This NEOS solver executes on a Sun workstation. Sun, Sun Microsystems, the Sun Logo and the Powered by Sun Logo are trademarks or registered trademarks of Sun Microsystems, Inc. in the U.S. and other countries.

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:

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Please do not click the 'Submit to NEOS' button more than once.

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