[Scip] SCIP-2.1.1 and SCIP-3.0.1 give different optimal values

[Victor Miller]

This looks like it might be a bug in presolve.  As a guess I set maxrounds
to 3 in 3.0.1 and then it found the right optimal solution.

Victor


On Fri, May 31, 2013 at 10:39 AM, Masahiro Sakai
<masahiro.sakai at gmail.com>wrote:
Hi,

I solved a minimization MILP problem attached as rand717_l2.wcnf.lp.gz
using SCIP-2.1.1 and SCIP-3.0.1, but they delivered differenct results:

* SCIP-2.1.1 returned 2205487 as the optimal value, while
* SCIP-3.0.1 returned 2223207 as the optimal value.

I'm wondering whether it is a bug of SCIP-3.0.1 or just a numerical
problem.

The problem rand717_l2.wcnf.lp is converted from a weighted partial
Max-SAT problem rand717_l2.wcnf.gz. And I used SCIP binaries
downloaded from the SCIP website: scip-2.1.1.linux.x86_64.gnu.opt.spx.zip
and scip-3.0.1.linux.x86_64.gnu.opt.spx.zip.

Thanks in advance,

Masahiro

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On Fri, May 31, 2013 at 10:39 AM, Masahiro Sakai
<masahiro.sakai at gmail.com>wrote:

> Hi,
>
> I solved a minimization MILP problem attached as rand717_l2.wcnf.lp.gz
> using SCIP-2.1.1 and SCIP-3.0.1, but they delivered differenct results:
>
> * SCIP-2.1.1 returned 2205487 as the optimal value, while
> * SCIP-3.0.1 returned 2223207 as the optimal value.
>
> I'm wondering whether it is a bug of SCIP-3.0.1 or just a numerical
> problem.
>
> The problem rand717_l2.wcnf.lp is converted from a weighted partial
> Max-SAT problem rand717_l2.wcnf.gz. And I used SCIP binaries
> downloaded from the SCIP website: scip-2.1.1.linux.x86_64.gnu.opt.spx.zip
> and scip-3.0.1.linux.x86_64.gnu.opt.spx.zip.
>
> Thanks in advance,
>
> Masahiro
>
> _______________________________________________
> Scip mailing list
> Scip at zib.de
> http://listserv.zib.de/mailman/listinfo/scip
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>
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