[Scip] add constraints while solver is running?

[Ambros Gleixner]

Hi Sandy,

both local and global constraints can be created and added during the 
solution process as usual via SCIPcreateCons...() and SCIPaddCons().

However, you do not have to/should not add the upper bound as a 
constraint, but can use the parameter "limits/objective"; this can be 
changed at any time during the solution process via

    SCIP_CALL( SCIPsetRealParam(scip, "limits/objective", value) );

Also, you might consider transferring the solutions themselves via 
SCIPtrySol() or SCIPaddSol() because this can improve the performance of 
some primal heuristics; but then again the solution from one subproblem 
may not be feasible for the others and hence be rejected.

Hope this helps,

Ambros




Am 29.03.2013 19:25, schrieb Sandy Ryza:
> Hi All,
>
> Is there an easy way in SCIP to add constraints while the solver is
> running?  My use case is that I want to try running multiple solvers in
> parallel on different subproblems, and if one of the solvers comes
> across a good solution I want to be able to set the upper bound on the
> other ones for better pruning.
>
> thanks for any guidance,
> Sandy
>
>
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-- 
____________________________________________________________
Ambros M. Gleixner
Zuse Institute Berlin - Matheon - Berlin Mathematical School
http://www.zib.de/gleixner