The NEOS Server offers FICO Xpress for the solution of mixed-integer linear
programming (MILP), linear programming (LP), and second-order conic
programming (SOCP) problems. Problems can be
submitted to FICO Xpress on the NEOS server in AMPL, GAMS, MOSEL, or MPS
The FICO Xpress optimizer is a commercial solver for linear programming and
mixed integer linear programming. XPRESS is part of the FICO Xpress
Optimization Suite. To learn more about the FICO Xpress Optimization Suite,
visit the FICO
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.
Note: An email address is required for any submissions to FICO Xpress solvers. This email address
will be forwarded to FICO and may be used by FICO for promotional purposes. When using the XML-RPC interface,
you must add the following line into the XML file that is submitted to NEOS:
<modelname>.optfile = 1 ;
optfile = 1