//############################################################################# void MibSHeuristic::lowerObjHeuristic() { /* optimize wrt to lower-level objective over current feasible lp feasible region */ MibSModel * model = MibSModel_; OsiSolverInterface * oSolver = model->getSolver(); //OsiSolverInterface * hSolver = new OsiCbcSolverInterface(); OsiSolverInterface* hSolver = new OsiSymSolverInterface(); double objSense(model->getLowerObjSense()); int lCols(model->getLowerDim()); int uCols(model->getUpperDim()); int * lColIndices = model->getLowerColInd(); int * uColIndices = model->getUpperColInd(); double * lObjCoeffs = model->getLowerObjCoeffs(); //int tCols(lCols + uCols); int tCols(oSolver->getNumCols()); //assert(tCols == oSolver->getNumCols()); hSolver->loadProblem(*oSolver->getMatrixByCol(), oSolver->getColLower(), oSolver->getColUpper(), oSolver->getObjCoefficients(), oSolver->getRowLower(), oSolver->getRowUpper()); int j(0); for(j = 0; j < tCols; j++){ if(oSolver->isInteger(j)) hSolver->setInteger(j); } double * nObjCoeffs = new double[tCols]; int i(0), index(0); CoinZeroN(nObjCoeffs, tCols); for(i = 0; i < lCols; i++){ index = lColIndices[i]; nObjCoeffs[index] = lObjCoeffs[i]; } //MibS objective sense is the opposite of OSI's! hSolver->setObjSense(objSense); hSolver->setObjective(nObjCoeffs); //double cutoff(model->getCutoff()); double cutoff(model->getKnowledgeBroker()->getIncumbentValue()); if(model->getNumSolutions()){ CoinPackedVector objCon; //double rhs(cutoff * objSense); //double smlTol(1.0); double rhs(cutoff); for(i = 0; i < tCols; i++){ objCon.insert(i, oSolver->getObjCoefficients()[i] * oSolver->getObjSense()); } hSolver->addRow(objCon, - hSolver->getInfinity(), rhs); } if(0) hSolver->writeLp("lobjheurstic"); if(0){ dynamic_cast<OsiCbcSolverInterface *> (hSolver)->getModelPtr()->messageHandler()->setLogLevel(0); } else{ dynamic_cast<OsiSymSolverInterface *> (hSolver)->setSymParam("prep_level", -1); dynamic_cast<OsiSymSolverInterface *> (hSolver)->setSymParam("verbosity", -2); dynamic_cast<OsiSymSolverInterface *> (hSolver)->setSymParam("max_active_nodes", 1); } hSolver->branchAndBound(); if(hSolver->isProvenOptimal()){ double upperObjVal(0.0); /*****************NEW ******************/ MibSSolution *mibSol = NULL; OsiSolverInterface * lSolver = model->bS_->setUpModel(hSolver, true); if(0){ lSolver->writeLp("tmp"); } if(0){ dynamic_cast<OsiCbcSolverInterface *> (lSolver)->getModelPtr()->messageHandler()->setLogLevel(0); } else{ dynamic_cast<OsiSymSolverInterface *> (lSolver)->setSymParam("prep_level", -1); dynamic_cast<OsiSymSolverInterface *> (lSolver)->setSymParam("verbosity", -2); dynamic_cast<OsiSymSolverInterface *> (lSolver)->setSymParam("max_active_nodes", 1); } lSolver->branchAndBound(); if (lSolver->isProvenOptimal()){ const double * sol = hSolver->getColSolution(); double objVal(lSolver->getObjValue() * objSense); double etol(etol_); double lowerObj = getLowerObj(sol, objSense); double * optUpperSolutionOrd = new double[uCols]; double * optLowerSolutionOrd = new double[lCols]; CoinZeroN(optUpperSolutionOrd, uCols); CoinZeroN(optLowerSolutionOrd, lCols); if(fabs(objVal - lowerObj) < etol){ /** Current solution is bilevel feasible **/ for(i = 0; i < tCols; i++) upperObjVal += hSolver->getColSolution()[i] * oSolver->getObjCoefficients()[i]; mibSol = new MibSSolution(hSolver->getNumCols(), hSolver->getColSolution(), upperObjVal, model); model->storeSolution(BlisSolutionTypeHeuristic, mibSol); mibSol = NULL; } else{ /* solution is not bilevel feasible, create one that is */ const double * uSol = hSolver->getColSolution(); const double * lSol = lSolver->getColSolution(); int numElements(hSolver->getNumCols()); int i(0), pos(0), index(0); double * lpSolution = new double[numElements]; double upperObj(0.0); //FIXME: problem is still here. indices may be wrong. //also is all this necessary, or can we just paste together uSol and lSol? //this may be an old comment for(i = 0; i < numElements; i++){ pos = model->bS_->binarySearch(0, lCols - 1, i, lColIndices); if(pos < 0){ pos = model->bS_->binarySearch(0, uCols - 1, i, uColIndices); if (pos >= 0){ optUpperSolutionOrd[pos] = uSol[i]; } } else{ optLowerSolutionOrd[pos] = lSol[pos]; } } for(i = 0; i < uCols; i++){ index = uColIndices[i]; lpSolution[index] = optUpperSolutionOrd[i]; upperObj += optUpperSolutionOrd[i] * oSolver->getObjCoefficients()[index]; } for(i = 0; i < lCols; i++){ index = lColIndices[i]; lpSolution[index] = optLowerSolutionOrd[i]; upperObj += optLowerSolutionOrd[i] * oSolver->getObjCoefficients()[index]; } if(model->checkUpperFeasibility(lpSolution)){ mibSol = new MibSSolution(hSolver->getNumCols(), lpSolution, upperObj * oSolver->getObjSense(), model); model->storeSolution(BlisSolutionTypeHeuristic, mibSol); mibSol = NULL; } delete [] lpSolution; } } delete lSolver; } delete hSolver; }