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

[Masahiro Sakai]

Hi Victor and Timo,

Thank you very much for your quick response and help.
I'll try to follow the debugging instructions.

Best regards,

Masahiro

2013/6/1 Timo Berthold <berthold at zib.de>:
> Hi Masahiro,
>
> me and most of the SCIP team are currently on a business trip, and will
> have a look into it after our return next week.
> If you have the possibility to compile SCIP on your own, you might follow
> the instruction at http://scip.zib.de/doc/html/DEBUG.shtml
> Write out the solution with SCIP 2.1.1, compile SCIP 3.0.1 with a
> #define SCIP_DEBUG_SOLUTION "<pathtothesolfile>.sol" in debug.h
> and run SCIP 3.0.1.
>
> @Victor: Thanks for your very quick reply, that's a good hint. :-)
>
> Best regards,
> Timo
>
>> 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
>>
>> ______________________________
>>>
>>> _________________
>>> Scip mailing list
>>> Scip at zib.de
>>> http://listserv.zib.de/mailman/listinfo/scip
>>
>>
>>
>> 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
>>>
>>>
>> _______________________________________________
>> Scip mailing list
>> Scip at zib.de
>> http://listserv.zib.de/mailman/listinfo/scip
>>
>