[Clp] getPrimalRays does not return direction of unboundedness

[John Forrest]

Aykut,

Behaviour is due to a "feature".  initialSolve presolves the problem, 
solves it and finds it to be dual infeasible.  Because
ClpSimplex::moreSpecialOptions_ default has         "2 bit - if 
presolved problem infeasible return" set it does not create a ray.

So - either -

do solver->resolve() if infeasible - this will give ray as does not do 
presolve

or

add the elegant line

dynamic_cast<OsiClpSolverInterface * 
 >(solver)->getModelPtr()->setMoreSpecialOptions(0);

before initialSolve

John Forrest

On 11/09/14 22:39, Aykut Bulut wrote:
> Hi,
>
> I use OsiClp for my application and getPrimalRays() function does not 
> return any unboundedness direction when it should (when dual is 
> infeasible and primal is not). You can see the attached code and mps file.
>
> Any help would be appreciated.
>
> Best,
> Aykut
>
>
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