[Cbc] issue with cbcstrategy on small MILP
Matthew Galati
Matthew.Galati at sas.com
Mon Nov 3 13:42:44 EST 2008
If I solve without the CbcStrategy, it solves the problem. If I use the default CbcStrategy, it claims infeasible.
.lp file is attached
Thanks,
Matt
Without Strategy:
Cbc0032I Strong branching done 34 times (49 iterations), fathomed 3 nodes and fixed 3 variables
Cbc0035I Maximum depth 3, 36 variables fixed on reduced cost
Clp0000I Optimal - objective value -137.844
Clp0000I Optimal - objective value -137.844
With Strategy:
Clp0000I Optimal - objective value -138.653
Clp0000I Optimal - objective value -138.653
Cbc0001I Search completed - best objective 1e+50, took 392 iterations and 0 nodes (0.22 seconds)
Cbc0035I Maximum depth 0, 0 variables fixed on reduced cost
Clp0006I 0 Obj -138.653 Primal inf 25.5703 (9) Dual inf 2.77501e+11 (3)
Clp0006I 4 Obj -132.969 Primal inf 5 (5)
Clp0001I Primal infeasible - objective value -132.969
#include "CbcModel.hpp"
#include "CbcStrategy.hpp"
#include "OsiClpSolverInterface.hpp"
int main(int argc, char ** argv){
OsiClpSolverInterface si;
si.readLp("subProbInitCbc.lp");
CbcModel cbc(si);
CbcStrategyDefault cbcStrategyDefault;
cbc.setStrategy(cbcStrategyDefault);
cbc.branchAndBound();
return 0;
}
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