The NEOS Server offers IPOPT for the solution of nonlinear programs in
format. IPOPT is an open source software package for large-scale nonlinear
optimization. It implements a primal-dual interior point algorithm,
which uses a filter line search method to ensure global convergence.
IPOPT was developed by Andreas Wächter, Lorenz T. Biegler, Arvind
Raghunathan, and Yi-Dong Lang. For more information, see the
IPOPT home page.
A list of papers and publications describing the algorithm is available
Using the NEOS Server with IPOPT
The user must submit a model in AMPL
format to solve a nonlinear programming problem. The
examples section of the AMPL website provides examples of models in AMPL format.
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
The commands file may include AMPL commands and option settings for IPOPT.
To specify solver options, add
option ipopt_options "OPTIONS";
where OPTIONS is a list of one or more of the IPOPT options. See the
options available via the AMPL interface.