The NEOS Server offers Knitro
for the solution of general nonconvex, nonlinearly constrained optimization
problems in GAMS format. Knitro also can
be used to solve simpler classes of problems such as
unconstrained problems, bound constrained problems, linear programming (LP)
problems and quadratic programming (QP) problems.
Knitro was developed by
Mary Beth Hribar,
Jorge Nocedal and
Richard Waltz with
additional help from Guanghui Liu, Marcelo Marazzi, Todd Plantenga and
Jose Luis Morales. For a detailed
description of Knitro, see
R. H. Byrd, J. Nocedal, and R. A. Waltz. 2006.
KNITRO: An Integrated Package for Nonlinear Optimization.
In: G. di Pillo and M. Roma, editors. Large-Scale Nonlinear Optimization.
Springer-Verlag, p. 35-59.
Knitro is available from Artelys. For more information on Knitro, see the Knitro website.
Using the NEOS Server with Knitro
The user must submit a model in GAMS
format to solve a nonlinearly constrained optimization problem. For security purposes, the model
submitted must adhere to the following conventions:
If you are unfamiliar with GAMS, the GAMS Documentation Center provides a GAMS User's Guide.
Examples of models in GAMS
format can be found in the
GAMS model library and an
is also available.
- It must be self contained, i.e., no $include or $batinclude statements.
- It may not execute external programs, i.e., no $call or execute statements.
- It may not create files, i.e., no put files or $echo statements.
An options file can be used to specify Knitro options. 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.
The NEOS Server initially 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 the
modeling language for further information.