[Scip] Fractional dual bound when the objective is integer

[Stefan Vigerske]

Hi,

On 07/10/2012 06:00 PM, Stefan Vigerske wrote:
> I think you should see only integral values in the dual bounds column of
> the SCIP output, because fractional optimal values from the LP
> relaxation are automatically rounded up.

I was informed that the displayed dual bound is no rounded up if the 
objective is integral.
However, for checking whether the gap is closed, the dual bound is 
rounded up.

Sorry for the confusion,
Stefan

>
> On 07/10/2012 05:47 PM, Daniel Karch wrote:
>> Hi,
>>
>> I have a short question. I am working on an ILP model (minimization) where
>> the objective value is always integer.
>> Suppose that SCIP's current dual bound is fractional, say 7.5 ... By the
>> integrality of the objective we know that
>> 8 is also a valid lower bound. Does SCIP take this into account? Would it
>> even help?
>>
>> Best regards,
>>
>>     Daniel
>>
>>
>>
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