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NEOS Interfaces to LANCELOT

WWW Form & Sample Submissions


The NEOS Server offers LANCELOT for the solution of nonlinearly constrained optimization problems in AMPL format. LANCELOT is suitable for large nonlinearly constrained problems and implements an augmented Lagrangian algorithm. Additional information on LANCELOT is available in the User's Guide for LANCELOT.

LANCELOT was developed by Andy Conn, Nick Gould, and Philippe Toint.

Using the NEOS Server with LANCELOT

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 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 LANCELOT. To specify solver options, add

option lancelot_options "OPTIONS";
where OPTIONS is one or more of the LANCELOT options, which are listed in the LANCELOT 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.