[Cbc] Wrong answer on pk1 with CBC 2.5.0

[John Forrest]

Emilie,

Somehow with the combination of those primal and dual tolerances, Clp
was managing to get a solution with objective less than 0.0 (which is
not really possible) and oscillating.  It got confused.  I have put a
patch in, which can't do any harm and solves immediate problem.  Not the
best solution.

John Forrest


On Mon, 2010-10-11 at 18:50 -0700, Emilie Danna wrote:
> Hi,
> 
> I tried to submit a bug at https://projects.coin-or.org/Cbc/newticket
> but I get an error ("TICKET_CREATE privileges are required to perform
> this operation", and I don't have a login) so I guess I'll just send
> it here.
> 
> On pk1 from MIPLIB, CBC 2.5.0 claims the optimal value is 22, whereas
> the true optimal value indicated on the MIPLIB website is 11. See the
> log attached, it also contains the parameter values I have used.
> I'm on x86_64. I built CBC without any non-default options.
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