[Scip] How good are SCIP solutions?

[michael.winkler@zib.de]

Hi Ina,

for minimization problems the solution with the smaller value is the
better solution. But, it might happen, that due to numerics, some solution
are not feasible in the original problem.

If you run SCIP from command line with the "-f" option, the last solution
is checked in the original problem and if it violates some constraints or
bounds then there will be a message about it.
If you run SCIP from the interactive shell or with the "-c" option (from
command line) you need to call "checksol" after "optimize", to check the
best known solution in the original problem.

I don't know the tolerances that were used to check the solutions, for
which the solutionvalues on the MINLPlib are given.

Best,
Michael

> Dear All,
>
> I'm using SCIP to solve MINLPs. I tried to solve some instances from
> libraries such as the MINLPLib.
> In these libraries the best solutions are usually given. But how do I know
> which solution is the better one, the given solution or the solution I got
> from solving the instance with SCIP? Suppose I have a minimization
> problem, can I then always assume that the smaller objective value is the
> better one?
>
> Regards,
> Ina
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