void OsiPresolve::postsolve(bool updateStatus) { // Messages CoinMessages messages = CoinMessage(presolvedModel_->messages().language()); if (!presolvedModel_->isProvenOptimal()) { presolvedModel_->messageHandler()->message(COIN_PRESOLVE_NONOPTIMAL, messages) <<CoinMessageEol; } // this is the size of the original problem const int ncols0 = ncols_; const int nrows0 = nrows_; const CoinBigIndex nelems0 = nelems_; // reality check assert(ncols0==originalModel_->getNumCols()); assert(nrows0==originalModel_->getNumRows()); // this is the reduced problem int ncols = presolvedModel_->getNumCols(); int nrows = presolvedModel_->getNumRows(); double *acts = new double [nrows0]; double *sol = new double [ncols0]; CoinZeroN(acts,nrows0); CoinZeroN(sol,ncols0); unsigned char * rowstat=NULL; unsigned char * colstat = NULL; CoinWarmStartBasis * presolvedBasis = dynamic_cast<CoinWarmStartBasis*>(presolvedModel_->getWarmStart()); if (!presolvedBasis) updateStatus=false; if (updateStatus) { colstat = new unsigned char[ncols0+nrows0]; # ifdef ZEROFAULT memset(colstat,0,((ncols0+nrows0)*sizeof(char))) ; # endif rowstat = colstat + ncols0; int i; for (i=0;i<ncols;i++) { colstat[i] = presolvedBasis->getStructStatus(i); } for (i=0;i<nrows;i++) { rowstat[i] = presolvedBasis->getArtifStatus(i); } } delete presolvedBasis; # if PRESOLVE_CONSISTENCY > 0 if (updateStatus) { int basicCnt = 0 ; int i ; for (i = 0 ; i < ncols ; i++) { if (colstat[i] == CoinWarmStartBasis::basic) basicCnt++ ; } for (i = 0 ; i < nrows ; i++) { if (rowstat[i] == CoinWarmStartBasis::basic) basicCnt++ ; } assert (basicCnt == nrows) ; } # endif /* Postsolve back to the original problem. The CoinPostsolveMatrix object assumes ownership of sol, acts, colstat, and rowstat. */ CoinPostsolveMatrix prob(presolvedModel_, ncols0, nrows0, nelems0, presolvedModel_->getObjSense(), sol, acts, colstat, rowstat); postsolve(prob); # if PRESOLVE_CONSISTENCY > 0 if (updateStatus) { int basicCnt = 0 ; int i ; for (i = 0 ; i < ncols0 ; i++) { if (prob.getColumnStatus(i) == CoinWarmStartBasis::basic) basicCnt++ ; } for (i = 0 ; i < nrows0 ; i++) { if (prob.getRowStatus(i) == CoinWarmStartBasis::basic) basicCnt++ ; } assert (basicCnt == nrows0) ; } # endif originalModel_->setColSolution(sol); if (updateStatus) { CoinWarmStartBasis *basis = dynamic_cast<CoinWarmStartBasis *>(presolvedModel_->getEmptyWarmStart()); basis->setSize(ncols0,nrows0); int i; for (i=0;i<ncols0;i++) { CoinWarmStartBasis::Status status = static_cast<CoinWarmStartBasis::Status> (prob.getColumnStatus(i)); /* FIXME: these asserts seem correct, but seem to reveal some bugs in CoinPresolve */ // assert(status != CoinWarmStartBasis::atLowerBound || originalModel_->getColLower()[i] > -originalModel_->getInfinity()); // assert(status != CoinWarmStartBasis::atUpperBound || originalModel_->getColUpper()[i] < originalModel_->getInfinity()); basis->setStructStatus(i,status); } for (i=0;i<nrows0;i++) { CoinWarmStartBasis::Status status = static_cast<CoinWarmStartBasis::Status> (prob.getRowStatus(i)); /* FIXME: these asserts seem correct, but seem to reveal some bugs in CoinPresolve */ // assert(status != CoinWarmStartBasis::atUpperBound || originalModel_->getRowLower()[i] > -originalModel_->getInfinity()); // assert(status != CoinWarmStartBasis::atLowerBound || originalModel_->getRowUpper()[i] < originalModel_->getInfinity()); basis->setArtifStatus(i,status); } originalModel_->setWarmStart(basis); delete basis ; } }
void CbcTreeArray::cleanTree(CbcModel * model, double cutoff, double & bestPossibleObjective) { int j; int nNodes = size(); int lastNode = nNodes + 1; CbcNode ** nodeArray = new CbcNode * [lastNode]; int * depth = new int [lastNode]; int k = 0; int kDelete = lastNode; bestPossibleObjective = 1.0e100 ; /* Destructively scan the heap. Nodes to be retained go into the front of nodeArray, nodes to be deleted into the back. Store the depth in a correlated array for nodes to be deleted. */ for (j = 0; j < nNodes; j++) { CbcNode * node = nodes_.front(); nodes_.front()->setOnTree(false); std::pop_heap(nodes_.begin(), nodes_.end(), comparison_); nodes_.pop_back(); double value = node ? node->objectiveValue() : COIN_DBL_MAX; if (node && value >= cutoff) { // double check in case node can change its mind! value = node->checkIsCutoff(cutoff); } if (value >= cutoff || !node->active()) { if (node) { nodeArray[--kDelete] = node; depth[kDelete] = node->depth(); } } else { bestPossibleObjective = CoinMin(bestPossibleObjective, value); nodeArray[k++] = node; } } if (lastNode_) { double value = lastNode_->objectiveValue(); bestPossibleObjective = CoinMin(bestPossibleObjective, value); if (value >= cutoff || !lastNode_->active()) { nodeArray[--kDelete] = lastNode_; depth[kDelete] = lastNode_->depth(); lastNode_ = NULL; } } CbcCompareDefault * compareDefault = dynamic_cast<CbcCompareDefault *> (comparison_.test_); assert (compareDefault); compareDefault->setBestPossible(bestPossibleObjective); compareDefault->setCutoff(cutoff); /* Rebuild the heap using the retained nodes. */ for (j = 0; j < k; j++) { CbcNode * node = nodeArray[j]; node->setOnTree(true); nodes_.push_back(node); std::push_heap(nodes_.begin(), nodes_.end(), comparison_); } /* Sort the list of nodes to be deleted, nondecreasing. */ CoinSort_2(depth + kDelete, depth + lastNode, nodeArray + kDelete); /* Work back from deepest to shallowest. In spite of the name, addCuts1 is just a preparatory step. When it returns, the following will be true: * all cuts are removed from the solver's copy of the constraint system; * lastws will be a basis appropriate for the specified node; * variable bounds will be adjusted to be appropriate for the specified node; * addedCuts_ (returned via addedCuts()) will contain a list of cuts that should be added to the constraint system at this node (but they have not actually been added). Then we scan the cut list for the node. Decrement the reference count for the cut, and if it's gone to 0, really delete it. I don't yet see why the checks for status != basic and addedCuts_[i] != 0 are necessary. When reconstructing a node, these checks are used to skip over loose cuts, excluding them from the reconstituted basis. But here we're just interested in correcting the reference count. Tight/loose should make no difference. Arguably a separate routine should be used in place of addCuts1. It's doing more work than needed, modifying the model to match a subproblem at a node that will be discarded. Then again, we seem to need the basis. */ for (j = lastNode - 1; j >= kDelete; j--) { CbcNode * node = nodeArray[j]; CoinWarmStartBasis *lastws = model->getEmptyBasis() ; model->addCuts1(node, lastws); // Decrement cut counts assert (node); //assert (node->nodeInfo()); int numberLeft = (node->nodeInfo()) ? node->nodeInfo()->numberBranchesLeft() : 0; int i; for (i = 0; i < model->currentNumberCuts(); i++) { // take off node CoinWarmStartBasis::Status status = lastws->getArtifStatus(i + model->numberRowsAtContinuous()); if (status != CoinWarmStartBasis::basic && model->addedCuts()[i]) { if (!model->addedCuts()[i]->decrement(numberLeft)) delete model->addedCuts()[i]; } } // node should not have anything pointing to it if (node->nodeInfo()) node->nodeInfo()->throwAway(); delete node ; delete lastws ; } delete [] nodeArray; delete [] depth; }