The NEOS Server offers IPOPT for the solution of nonlinear programs.
Problems can be submitted to IPOPT on the NEOS server in AMPL or GAMS
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.
The main authors of IPOPT are Andreas Wächter and Carl Laird, with
additional development by Lorenz T. Biegler, Arvind Raghunathan, and Yi-Dong
For more information, see the IPOPT home page. A list of
papers and publications describing the algorithm is available here.
The user must submit a model in GAMS
format to solve an optimization problem. For security purposes, the model
submitted must adhere to the following conventions:
If you are unfamiliar with GAMS, the
GAMS Documentation includes a
GAMS Tutorial and
Examples of models in GAMS format can be found in the
GAMS model library.
By default, the NEOS Server limits the amount of output generated in the listing
file by turning off the symbol and unique element list, symbol cross references,
and restricting the rows and columns listed to zero. This behavior can be changed
by specifying the appropriate options in the model file. See the
documentation on GAMS output
for further information.
You may optionally submit an options file if you wish to override the default parameter settings for the solver.
Currently, the NEOS Server can only use optfile=1 with GAMS input. Therefore, any model that specifies a different options file will not work as intended.
<modelname>.optfile = 1 ;
optfile = 1