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The NEOS Server offers SNOPT for the solution of nonlinearly constrained optimization problems in AMPL format. SNOPT is suitable for large nonlinearly constrained problems with a modest number of degrees of freedom.

SNOPT implements a sequential programming algorithm that uses a smooth augmented Lagrangian merit function and makes explicit provision for infeasibility in the original problem and in the quadratic programming subproblems. Additional information on SNOPT can be found in the User's Guide for SNOPT (Version 5.3)

SNOPT was developed by Philip E. Gill, Walter Murray, and Michael Saunders.

Using the NEOS Server for SNOPT

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 SNOPT with, for example,
option snopt_options "timing=3 outlev=2";
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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