[Coin-discuss] Strange termination

[Jean-Sebastien Roy]

Matthew Saltzman wrote:
> The docs are not clear what the circumstances are that lead to this 
> return code.  There is a CPXMIP_UNBOUNDED (unbdd ray found) and a 
> CPXMIP_INFEAS (proven infeasible).  So I will guess that 
> CPXMIP_INForUNBD must arise in some ambiguous case.  We'd need to get 
> CPLEX to weigh in on whether the two cases are distinguishable with some 
> additional calls.

In the non-mip case, CPX_STAT_INForUNBD may be returned when the 
presolve is present, since CPLEX's presolve cannot distinguish the two 
cases. Disabling the presolve and resolving lead to the proper return 
code (see OsiCpxSolverInterface.cpp for the relevant code).

Maybe it's the same in the mip case ?

Regards,

js