[Cbc] Objective value wrong

[Haroldo Santos]

It seems that there are 2 erratic cut generators here.

Running with flow off gomory off the correct solution is produced.

If flow covers are on the problem is declared infeasible.
Gomory cuts activated generate and invalid bound.

On Mon, Nov 27, 2017 at 9:54 AM, Haroldo Santos <haroldo.santos at gmail.com>
wrote:

> Hi,
>
> Tested with trunk, it appears that this problem is related to cut
> generators.
>
> Running with cuts off the solution with cost 442 is generated, but
> optimality is not proved as expected because the dual bound is weaker...
>
>
>
> On Mon, Nov 27, 2017 at 2:49 AM, Gleb Belov <gleb.belov at monash.edu> wrote:
>
>> Hi,
>>
>> on this instance: https://www.dropbox.com/s/meay5xl4op720l7/dcmst_v2
>> 0a50d4.mps.gz?dl=0 (68 KB) CBC report optimum 451 while others say 442.
>> Using stable/2.9
>>
>> Thank you,
>> Gleb
>>
>> --
>> Dr Gleb Belov       Monash University      +61 3 9903 1622
>> <+61%203%209903%201622>
>>
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>>
>
>
> --
> =============================================================
> Haroldo Gambini Santos
> Computing Department
> Universidade Federal de Ouro Preto - UFOP
> email: haroldo [at ] iceb.ufop.br
> home/research page: www.decom.ufop.br/haroldo
>
>
> It has long been an axiom of mine that the little things are infinitely
> the most important.
> -- Sir Arthur Conan Doyle, "A Case of Identity"
>



-- 
=============================================================
Haroldo Gambini Santos
Computing Department
Universidade Federal de Ouro Preto - UFOP
email: haroldo [at ] iceb.ufop.br
home/research page: www.decom.ufop.br/haroldo


It has long been an axiom of mine that the little things are infinitely
the most important.
-- Sir Arthur Conan Doyle, "A Case of Identity"
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