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NEOS Interfaces to SNOPT

WWW Form & Sample Submissions


The NEOS Server offers SNOPT for the solution of nonlinearly constrained optimization problems in AMPL format. SNOPT is especially effective for nonlinear programs whose functions and gradients are expensive to evaluate. The functions should be smooth but do not need to be convex.

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 7.

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 nonlinear programming problem. Examples of models in AMPL format can be found in the netlib collection.

The nonlinear programming problem 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. The commands file must not contain the model or data commands. The model and data files are renamed internally by NEOS.

The commands file may contain any AMPL command or set options for SNOPT. To specify solver options, add

option snopt_options "OPTIONS";
where OPTIONS is a list of one or more of the SNOPT options, which are listed at SNOPT Directives for AMPL.

Web Submission Form
Model File
Enter the location of the AMPL model (local file)
Data File
Enter the location of the AMPL data file (local file)
Commands File
Enter the location of the AMPL commands file (local file)
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.