[Coin-discuss] CLP/CBC: problems with solutions on various platforms

[Kish Shen]

Hi,

I have been having problems with a couple of MIP problems using CLP/CBC via the 
OsiClpSolverInterface. I have two issues:

1) The solver is unable to find a solution to a problem when there is a solution.
2) A solution is returned which violates some of the constraints.

I have tried running these problems on Linux (running on x86 processors) and Mac OS X 
(both Intel and PPC), and the behaviour is different for each platform, i.e., the problems
will be solved correctly on one platform but not the other, but none of the platforms seem 
to solve all the problems correctly.

I am using the trunk branch of CLP/CBC, which I downloaded about two months ago (Nov 8).
I am using the Simplex solver in this case. I could generate C++ programs with the calls to 
CLP/CBC that reproduce these problems. 

John, if you have time and can look at these problems, please let me know and I can send 
them to you. 

Cheers,

Kish