[Osi] OsiClp and OsiCbc branchAndBound

Goossens Jan-Willem Jan-Willem.Goossens at nc3a.nato.int
Fri Dec 11 10:42:34 EST 2009


All,

The attached MPS file (a small minimization MIP) gives the wrong solution in OsiClp->branchAndBound(), and crashes in (the debug build) of OsiCbc->branchAndBound().
Admittedly, I don't didn't test with the latest sources out of the repository.

OsiClp->branchAndBound() returns the solution with objective value 125165, while 124725 is optimal.

In Debug mode, the OsiCbc->branchAndBound() fails on the assert in CbcBranchActual.cpp line 1235:
#ifndef NDEBUG
    double nearest = floor(value+0.5);
    assert (fabs(value-nearest)>info->integerTolerance_);
#endif
In non-Debug mode, OsiCbc returns the correct solution of 124725.

Can somebody confirm this behaviour in the latest builds?
Regards,

Jan-Willem
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