The NEOS Server offers SCIP for the solution of mixed-integer linear and nonlinear programming problems in AMPL format. Not all elements of AMPL have been implmented, yet.
SCIP is a framework for Constraint Integer Programming oriented towards the needs of Mathematical Programming experts who want to have total control of the solution process and access detailed information. SCIP can also be used as pure MIP solver or as framework for branch-cut-and-price.
SCIP can be linked with a number of LP solvers and the NLP solver IPOPT. See this benchmark for the relative performance of SCIP and a shared-memory parallel version FiberSCIP.
Source and documentation are available from the SCIP Homepage
This solver was implemented by Hans Mittelmann and executes at
If non-standard SCIP parameter settings are required, the user may also submit changes from this default parameter file. Only the line(s) in which a parameter is changed from default should be submitted such as limits/solutions = 1 if SCIP should stop when the first feasible solution has been found. When submitting via e-mail or XML-RPC delete empty tokens!
The administrator of SCIP reserves the right to keep and use problem instances submitted through NEOS for testing and debugging purposes.
The user must submit a model in AMPL format. Examples are provided in the examples section of the AMPL website.
The problem must be specified in a model file. A data file and commands files may also be provided. If the commands file is specified, it must contain the AMPL solve command; however, it must not contain the model or data commands. The model and data files are renamed internally by NEOS. The commands file may include option settings for the solver. To specify solver options, add
solve
model
data
option scip_options 'OPTIONS';