[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #41: Incorrect Real Option calls causes COIN CLP to mark some problems as infeasible

[COIN-OR Branch-and-Cut MIP Solver]

#41: Incorrect Real Option calls causes COIN CLP to mark some problems as
infeasible
------------------------+---------------------------------------------------
 Reporter:  ltaylor     |       Owner:  somebody
     Type:  defect      |      Status:  new     
 Priority:  major       |   Milestone:          
Component:  component1  |     Version:          
 Keywords:              |  
------------------------+---------------------------------------------------
 In coinmp.cpp

 In function heading

 {{{
 SOLVAPI int CoinOptimizeProblem(HPROB hProb, int Method)
 }}}

 ... there are several calls to CoinGetIntOption for parameters
 that are actually Real values. The CoinGetIntOption always returns
 zero for options that are REAL. So those code lines actually
 will set, e.g., DualObjectiveLimit to zero.

 DualObjectiveLimit should be set high, and the default is 1e+308.
 When it is zero, CLP will mark some feasible problems as infeasible.

 This has been bothering me, as I have been using CoinMP.dll for
 optimizations,
 and it can sometimes get the right answer, but return the
 'PrimalInfeasible'
 message and status.

 I would check this change in myself, but I don't have those privileges
 (yet).

 LAT
 {{{
         pCoin->clp->setPrimalObjectiveLimit(CoinGetRealOption(hProb,
 COIN_REAL_PRIMALOBJLIM));
         pCoin->clp->setDualObjectiveLimit(CoinGetRealOption(hProb,
 COIN_REAL_DUALOBJLIM));
         pCoin->clp->setPrimalTolerance(CoinGetRealOption(hProb,
 COIN_REAL_PRIMALOBJTOL));
         pCoin->clp->setDualTolerance(CoinGetRealOption(hProb,
 COIN_REAL_DUALOBJTOL));

 ... skip ...
                 pCoin->clp->crash(CoinGetRealOption(hProb,
 COIN_REAL_CRASHGAP),
 }}}

-- 
Ticket URL: <https://projects.coin-or.org/Cbc/ticket/41>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.