[Cbc] Cbc with a linear solver using dual simplex

[Mathieu LACROIX]

Hi,
I am using cbc to solve a branch and cut with clp as linear solver. The 
code works fine but the problem is that the linear relaxation takes a 
long time to be solved. I changed my code to compute the linear 
relaxation using the dual simplex algorithm
(  dynamic_cast<OsiClpSolverInterface*> 
(osiLPsolver)->getModelPtr()->initialDualSolve(); instead of 
osiLPsolver->initialSolve() ) and the linear relaxation was computed 
really faster (3 minutes instead of 50 minutes). If I tried to then 
solve the problem (and not the linear relaxation) to optimality, no 
solution is found with the dual simplex algorithm (If I solve the 
problem with osiLPsolver->initialSolve(), I have a solution). However, 
the linear relaxation optimal values obtained with the two method are 
equal.
I suppose that the way I call the dual simplex algorithm is not correct 
but I did not find how to do this. Has somebody already done this, 
please? Or maybe it is not possible to use Cbc with the dual simplex 
algorithm for the linear solver?

Thanks,
Mathieu

-- 
Mathieu LACROIX
mathieu.lacroix at isima.fr
Université Blaise Pascal - Clermont Fd II
Laboratoire LIMOS
Bâtiment ISIMA - Bureau D112
Complexe scientifique des Cézeaux
63 177 Aubière, Cedex - France
Tel : 04.73.40.79.48
Fax : 04.73.40.76.39