void RepartitionInterface<LocalOrdinal, GlobalOrdinal, Node, LocalMatOps>::Build(Level &level) const {
FactoryMonitor m(*this, "Build", level);
RCP<Matrix> A = Get< RCP<Matrix> > (level, "A");
RCP<Xpetra::Vector<GO, LO, GO, NO> > amalgPartition = Get< RCP<Xpetra::Vector<GO, LO, GO, NO> > >(level, "AmalgamatedPartition");
RCP<AmalgamationInfo> amalgInfo = Get< RCP<AmalgamationInfo> >(level, "UnAmalgamationInfo");
RCP<const Teuchos::Comm< int > > comm = A->getRowMap()->getComm();
// const int myRank = comm->getRank();
ArrayRCP<GO> amalgPartitionData = amalgPartition->getDataNonConst(0);
RCP<const Map> rowMap = A->getRowMap();
RCP<const Map> nodeMap = amalgPartition->getMap();
// extract amalgamation information from matrix A
LO blockdim = 1; // block dim for fixed size blocks
GO offset = 0;
LO blockid = -1; // block id in strided map
LO nStridedOffset = 0; // DOF offset for strided block id "blockid" (default = 0)
LO stridedblocksize = blockdim; // size of strided block id "blockid" (default = fullblocksize, only if blockid!=-1 stridedblocksize <= fullblocksize)
// 1) check for blocking/striding information
// fill above variables
if(A->IsView("stridedMaps") &&
Teuchos::rcp_dynamic_cast<const StridedMap>(A->getRowMap("stridedMaps")) != Teuchos::null) {
Xpetra::viewLabel_t oldView = A->SwitchToView("stridedMaps"); // note: "stridedMaps are always non-overlapping (correspond to range and domain maps!)
RCP<const StridedMap> strMap = Teuchos::rcp_dynamic_cast<const StridedMap>(A->getRowMap());
TEUCHOS_TEST_FOR_EXCEPTION(strMap == Teuchos::null,Exceptions::BadCast,"MueLu::RepartitionInterface::Build: cast to strided row map failed.");
blockdim = strMap->getFixedBlockSize();
offset = strMap->getOffset();
blockid = strMap->getStridedBlockId();
if (blockid > -1) {
std::vector<size_t> stridingInfo = strMap->getStridingData();
for (size_t j = 0; j < Teuchos::as<size_t>(blockid); j++)
nStridedOffset += stridingInfo[j];
stridedblocksize = Teuchos::as<LocalOrdinal>(stridingInfo[blockid]);
} else {
stridedblocksize = blockdim;
}
oldView = A->SwitchToView(oldView);
GetOStream(Statistics0, -1) << "RepartitionInterface::Build():" << " found blockdim=" << blockdim << " from strided maps (blockid=" << blockid << ", strided block size=" << stridedblocksize << "). offset=" << offset << std::endl;
} else GetOStream(Statistics0, -1) << "RepartitionInterface::Build(): no striding information available. Use blockdim=1 with offset=0" << std::endl;
// vector which stores final (unamalgamated) repartitioning
RCP<Xpetra::Vector<GO, LO, GO, NO> > decomposition = Xpetra::VectorFactory<GO, LO, GO, NO>::Build(rowMap, false);
ArrayRCP<GO> decompEntries = decomposition->getDataNonConst(0);
TEUCHOS_TEST_FOR_EXCEPTION(Teuchos::as<int>(nodeMap->getNodeNumElements())*stridedblocksize != Teuchos::as<int>(rowMap->getNodeNumElements()), Exceptions::RuntimeError, "Inconsistency between nodeMap and dofMap");
RCP<std::map<GO,std::vector<GO> > > nodegid2dofgids = amalgInfo->GetGlobalAmalgamationParams();
// fill vector with information about partitioning
// TODO: we assume simple block maps here
// TODO: adapt this to usage of nodegid2dofgids
for(size_t i = 0; i < nodeMap->getNodeNumElements(); i++) {
// not fully sure about this. We're filling local ids in the decomposition vector with
// the results stored in array. The decomposition vector is created using the rowMap of A
// transform local node id to global node id.
//GO gNodeId = nodeMap->getGlobalElement(i);
// extract global DOF ids that belong to gNodeId
/*std::vector<GlobalOrdinal> DOFs = (*nodegid2dofgids)[gNodeId];
for(size_t j=0; j<stridedblocksize; j++) {
decompEntries[i*stridedblocksize + j] = myRank;
}*/
for (LO j = 0; j < stridedblocksize/*DOFs.size()*/; j++) {
// transform global DOF ids to local DOF ids using rowMap
// note: The vector decomposition is based on rowMap
//LO lDofId = rowMap->getLocalElement(DOFs[j]); // -> i doubt that we need this!
// put the same domain id to all DOFs of the same node
decompEntries[i*stridedblocksize + j] = amalgPartitionData[i];
//decompEntries[lDofId] = amalgPartitionData[i];
}
}
Set(level, "Partition", decomposition);
} //Build()
