[Osi] How to change solve algorithm to Dual or Barrier with OsiClpSolverInterface ?

[Sylvain R]

Hello,
I have been trying for quite a while to modify the algorithm that Clp uses to solve rather big linear problem. Clp says it is using Primal according to the solve-message I get (e.g. Clp0006I 6112  Obj 799905 Primal inf 50170.4 (1044)). 
But I would like to try to solve with the Dual method, and even the Barrier method. With CPLEX I have been able to do that and it considerably improved the run time (by x2 and x3).
I have been trying different ways:
1) call setIntParam with OsiDoDualInInitial to true.2) call setSolveOptions(const ClpSolve & options) with the proper ClpSolve object with method set to Dual or Barrier.
But it does not seem to change anything, it still goes at the same speed, nor does it display messages indicating it is doing anything differently.

Any idea? is it possible altogether?

Sylvain 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.coin-or.org/pipermail/osi/attachments/20110908/bbd331d5/attachment.html>