void LocalAggregationAlgorithm<LocalOrdinal, GlobalOrdinal, Node, LocalMatOps>::CoarsenUncoupled(GraphBase const & graph, Aggregates & aggregates) const {
Monitor m(*this, "Coarsen Uncoupled");
std::string orderingType;
switch(ordering_) {
case NATURAL:
orderingType="Natural";
break;
case RANDOM:
orderingType="Random";
break;
case GRAPH:
orderingType="Graph";
break;
default:
break;
}
GetOStream(Runtime1) << "Ordering: " << orderingType << std::endl;
GetOStream(Runtime1) << "Min nodes per aggregate: " << minNodesPerAggregate_ << std::endl;
GetOStream(Runtime1) << "Max nbrs already selected: " << maxNeighAlreadySelected_ << std::endl;
/* Create Aggregation object */
my_size_t nAggregates = 0;
/* ============================================================= */
/* aggStat indicates whether this node has been aggreated, and */
/* vertex2AggId stores the aggregate number where this node has */
/* been aggregated into. */
/* ============================================================= */
Teuchos::ArrayRCP<NodeState> aggStat;
const my_size_t nRows = graph.GetNodeNumVertices();
if (nRows > 0) aggStat = Teuchos::arcp<NodeState>(nRows);
for ( my_size_t i = 0; i < nRows; ++i ) aggStat[i] = READY;
/* ============================================================= */
/* Phase 1 : */
/* for all nodes, form a new aggregate with its neighbors */
/* if the number of its neighbors having been aggregated does */
/* not exceed a given threshold */
/* (GetMaxNeighAlreadySelected() = 0 ===> Vanek's scheme) */
/* ============================================================= */
/* some general variable declarations */
Teuchos::ArrayRCP<LO> randomVector;
RCP<MueLu::LinkedList> nodeList; /* list storing the next node to pick as a root point for ordering_ == GRAPH */
MueLu_SuperNode *aggHead=NULL, *aggCurrent=NULL, *supernode=NULL;
/**/
if ( ordering_ == RANDOM ) /* random ordering */
{
//TODO: could be stored in a class that respect interface of LinkedList
randomVector = Teuchos::arcp<LO>(nRows); //size_t or int ?-> to be propagated
for (my_size_t i = 0; i < nRows; ++i) randomVector[i] = i;
RandomReorder(randomVector);
}
else if ( ordering_ == GRAPH ) /* graph ordering */
{
nodeList = rcp(new MueLu::LinkedList());
nodeList->Add(0);
}
/* main loop */
{
LO iNode = 0;
LO iNode2 = 0;
Teuchos::ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0); // output only: contents ignored
while (iNode2 < nRows)
{
/*------------------------------------------------------ */
/* pick the next node to aggregate */
/*------------------------------------------------------ */
if ( ordering_ == NATURAL ) iNode = iNode2++;
else if ( ordering_ == RANDOM ) iNode = randomVector[iNode2++];
else if ( ordering_ == GRAPH )
{
if ( nodeList->IsEmpty() )
{
for ( int jNode = 0; jNode < nRows; ++jNode )
{
if ( aggStat[jNode] == READY )
{
nodeList->Add(jNode); //TODO optim: not necessary to create a node. Can just set iNode value and skip the end
break;
}
}
}
if ( nodeList->IsEmpty() ) break; /* end of the while loop */ //TODO: coding style :(
iNode = nodeList->Pop();
}
else {
throw(Exceptions::RuntimeError("CoarsenUncoupled: bad aggregation ordering option"));
}
/*------------------------------------------------------ */
/* consider further only if the node is in READY mode */
/*------------------------------------------------------ */
if ( aggStat[iNode] == READY )
{
// neighOfINode is the neighbor node list of node 'iNode'.
Teuchos::ArrayView<const LO> neighOfINode = graph.getNeighborVertices(iNode);
typename Teuchos::ArrayView<const LO>::size_type length = neighOfINode.size();
supernode = new MueLu_SuperNode;
try {
supernode->list = Teuchos::arcp<int>(length+1);
} catch (std::bad_alloc&) {
TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError, "MueLu::LocalAggregationAlgorithm::CoarsenUncoupled(): Error: couldn't allocate memory for supernode! length=" + Teuchos::toString(length));
}
supernode->maxLength = length;
supernode->length = 1;
supernode->list[0] = iNode;
int selectFlag = 1;
{
/*--------------------------------------------------- */
/* count the no. of neighbors having been aggregated */
/*--------------------------------------------------- */
int count = 0;
for (typename Teuchos::ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it)
{
int index = *it;
if ( index < nRows )
{
if ( aggStat[index] == READY ||
aggStat[index] == NOTSEL )
supernode->list[supernode->length++] = index;
else count++;
}
}
/*--------------------------------------------------- */
/* if there are too many neighbors aggregated or the */
/* number of nodes in the new aggregate is too few, */
/* don't do this one */
/*--------------------------------------------------- */
if ( count > GetMaxNeighAlreadySelected() ) selectFlag = 0;
}
// Note: the supernode length is actually 1 more than the
// number of nodes in the candidate aggregate. The
// root is counted twice. I'm not sure if this is
// a bug or a feature ... so I'll leave it and change
// < to <= in the if just below.
if (selectFlag != 1 ||
supernode->length <= GetMinNodesPerAggregate())
{
aggStat[iNode] = NOTSEL;
delete supernode;
if ( ordering_ == GRAPH ) /* if graph ordering */
{
for (typename Teuchos::ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it)
{
int index = *it;
if ( index < nRows && aggStat[index] == READY )
{
nodeList->Add(index);
}
}
}
}
else
{
aggregates.SetIsRoot(iNode);
for ( int j = 0; j < supernode->length; ++j )
{
int jNode = supernode->list[j];
aggStat[jNode] = SELECTED;
vertex2AggId[jNode] = nAggregates;
if ( ordering_ == GRAPH ) /* if graph ordering */
{
Teuchos::ArrayView<const LO> neighOfJNode = graph.getNeighborVertices(jNode);
for (typename Teuchos::ArrayView<const LO>::const_iterator it = neighOfJNode.begin(); it != neighOfJNode.end(); ++it)
{
int index = *it;
if ( index < nRows && aggStat[index] == READY )
{
nodeList->Add(index);
}
}
}
}
supernode->next = NULL;
supernode->index = nAggregates;
if ( nAggregates == 0 )
{
aggHead = supernode;
aggCurrent = supernode;
}
else
{
aggCurrent->next = supernode;
aggCurrent = supernode;
}
nAggregates++;
// unused aggCntArray[nAggregates] = supernode->length;
}
}
} // end of 'for'
// views on distributed vectors are freed here.
} // end of 'main loop'
nodeList = Teuchos::null;
/* Update aggregate object */
aggregates.SetNumAggregates(nAggregates);
/* Verbose */
{
const RCP<const Teuchos::Comm<int> > & comm = graph.GetComm();
if (IsPrint(Warnings0)) {
GO localReady=0, globalReady;
// Compute 'localReady'
for ( my_size_t i = 0; i < nRows; ++i )
if (aggStat[i] == READY) localReady++;
// Compute 'globalReady'
sumAll(comm, localReady, globalReady);
if(globalReady > 0)
GetOStream(Warnings0) << "Warning: " << globalReady << " READY nodes left" << std::endl;
}
if (IsPrint(Statistics1)) {
// Compute 'localSelected'
LO localSelected=0;
for ( my_size_t i = 0; i < nRows; ++i )
if ( aggStat[i] == SELECTED ) localSelected++;
// Compute 'globalSelected'
GO globalSelected; sumAll(comm, (GO)localSelected, globalSelected);
// Compute 'globalNRows'
GO globalNRows; sumAll(comm, (GO)nRows, globalNRows);
GetOStream(Statistics1) << "Nodes aggregated = " << globalSelected << " (" << globalNRows << ")" << std::endl;
}
if (IsPrint(Statistics1)) {
GO nAggregatesGlobal; sumAll(comm, (GO)nAggregates, nAggregatesGlobal);
GetOStream(Statistics1) << "Total aggregates = " << nAggregatesGlobal << std::endl;
}
} // verbose
/* ------------------------------------------------------------- */
/* clean up */
/* ------------------------------------------------------------- */
aggCurrent = aggHead;
while ( aggCurrent != NULL )
{
supernode = aggCurrent;
aggCurrent = aggCurrent->next;
delete supernode;
}
} // CoarsenUncoupled
void LeftoverAggregationAlgorithm<LocalOrdinal, GlobalOrdinal, Node, LocalMatOps>::AggregateLeftovers(GraphBase const &graph, Aggregates &aggregates) const {
Monitor m(*this, "AggregateLeftovers");
my_size_t nVertices = graph.GetNodeNumVertices();
int exp_nRows = aggregates.GetMap()->getNodeNumElements(); // Tentative fix... was previously exp_nRows = nVertices + graph.GetNodeNumGhost();
int myPid = graph.GetComm()->getRank();
my_size_t nAggregates = aggregates.GetNumAggregates();
int minNodesPerAggregate = GetMinNodesPerAggregate();
const RCP<const Map> nonUniqueMap = aggregates.GetMap(); //column map of underlying graph
const RCP<const Map> uniqueMap = graph.GetDomainMap();
MueLu::CoupledAggregationCommHelper<LO,GO,NO,LMO> myWidget(uniqueMap, nonUniqueMap);
//TODO JJH We want to skip this call
RCP<Xpetra::Vector<double,LO,GO,NO> > distWeights = Xpetra::VectorFactory<double,LO,GO,NO>::Build(nonUniqueMap);
// Aggregated vertices not "definitively" assigned to processors are
// arbitrated by ArbitrateAndCommunicate(). There is some
// additional logic to prevent losing root nodes in arbitration.
{
ArrayRCP<const LO> vertex2AggId = aggregates.GetVertex2AggId()->getData(0);
ArrayRCP<const LO> procWinner = aggregates.GetProcWinner()->getData(0);
ArrayRCP<double> weights = distWeights->getDataNonConst(0);
for (size_t i=0;i<nonUniqueMap->getNodeNumElements();i++) {
if (procWinner[i] == MUELU_UNASSIGNED) {
if (vertex2AggId[i] != MUELU_UNAGGREGATED) {
weights[i] = 1.;
if (aggregates.IsRoot(i)) weights[i] = 2.;
}
}
}
// views on distributed vectors are freed here.
}
//TODO JJH We want to skip this call
myWidget.ArbitrateAndCommunicate(*distWeights, aggregates, true);
// All tentatively assigned vertices are now definitive
// Tentatively assign any vertex (ghost or local) which neighbors a root
// to the aggregate associated with the root.
{
ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
ArrayRCP<const LO> procWinner = aggregates.GetProcWinner()->getData(0);
ArrayRCP<double> weights = distWeights->getDataNonConst(0);
for (my_size_t i = 0; i < nVertices; i++) {
if ( aggregates.IsRoot(i) && (procWinner[i] == myPid) ) {
// neighOfINode is the neighbor node list of node 'i'.
ArrayView<const LO> neighOfINode = graph.getNeighborVertices(i);
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int colj = *it;
if (vertex2AggId[colj] == MUELU_UNAGGREGATED) {
weights[colj]= 1.;
vertex2AggId[colj] = vertex2AggId[i];
}
}
}
}
// views on distributed vectors are freed here.
}
//TODO JJH We want to skip this call
myWidget.ArbitrateAndCommunicate(*distWeights, aggregates, true);
// All tentatively assigned vertices are now definitive
// Record the number of aggregated vertices
GO total_phase_one_aggregated = 0;
{
ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
GO phase_one_aggregated = 0;
for (my_size_t i = 0; i < nVertices; i++) {
if (vertex2AggId[i] != MUELU_UNAGGREGATED)
phase_one_aggregated++;
}
sumAll(graph.GetComm(), phase_one_aggregated, total_phase_one_aggregated);
GO local_nVertices = nVertices, total_nVertices = 0;
sumAll(graph.GetComm(), local_nVertices, total_nVertices);
/* Among unaggregated points, see if we can make a reasonable size */
/* aggregate out of it. We do this by looking at neighbors and seeing */
/* how many are unaggregated and on my processor. Loosely, */
/* base the number of new aggregates created on the percentage of */
/* unaggregated nodes. */
ArrayRCP<double> weights = distWeights->getDataNonConst(0);
double factor = 1.;
factor = ((double) total_phase_one_aggregated)/((double)(total_nVertices + 1));
factor = pow(factor, GetPhase3AggCreation());
for (my_size_t i = 0; i < nVertices; i++) {
if (vertex2AggId[i] == MUELU_UNAGGREGATED)
{
// neighOfINode is the neighbor node list of node 'iNode'.
ArrayView<const LO> neighOfINode = graph.getNeighborVertices(i);
int rowi_N = neighOfINode.size();
int nonaggd_neighbors = 0;
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int colj = *it;
if (vertex2AggId[colj] == MUELU_UNAGGREGATED && colj < nVertices)
nonaggd_neighbors++;
}
if ( (nonaggd_neighbors > minNodesPerAggregate) &&
(((double) nonaggd_neighbors)/((double) rowi_N) > factor))
{
vertex2AggId[i] = (nAggregates)++;
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int colj = *it;
if (vertex2AggId[colj]==MUELU_UNAGGREGATED) {
vertex2AggId[colj] = vertex2AggId[i];
if (colj < nVertices) weights[colj] = 2.;
else weights[colj] = 1.;
}
}
aggregates.SetIsRoot(i);
weights[i] = 2.;
}
}
} // for (i = 0; i < nVertices; i++)
// views on distributed vectors are freed here.
}
//TODO JJH We want to skip this call
myWidget.ArbitrateAndCommunicate(*distWeights, aggregates, true);
//All tentatively assigned vertices are now definitive
if (IsPrint(Statistics1)) {
GO Nphase1_agg = nAggregates;
GO total_aggs;
sumAll(graph.GetComm(), Nphase1_agg, total_aggs);
GetOStream(Statistics1, 0) << "Phase 1 - nodes aggregated = " << total_phase_one_aggregated << std::endl;
GetOStream(Statistics1, 0) << "Phase 1 - total aggregates = " << total_aggs << std::endl;
GO i = nAggregates - Nphase1_agg;
{ GO ii; sumAll(graph.GetComm(),i,ii); i = ii; }
GetOStream(Statistics1, 0) << "Phase 3 - additional aggregates = " << i << std::endl;
}
// Determine vertices that are not shared by setting Temp to all ones
// and doing NonUnique2NonUnique(..., ADD). This sums values of all
// local copies associated with each Gid. Thus, sums > 1 are shared.
// std::cout << "exp_nrows=" << exp_nRows << " (nVertices= " << nVertices << ", numGhost=" << graph.GetNodeNumGhost() << ")" << std::endl;
// std::cout << "nonUniqueMap=" << nonUniqueMap->getNodeNumElements() << std::endl;
RCP<Xpetra::Vector<double,LO,GO,NO> > temp_ = Xpetra::VectorFactory<double,LO,GO,NO> ::Build(nonUniqueMap,false); //no need to zero out vector in ctor
temp_->putScalar(1.);
RCP<Xpetra::Vector<double,LO,GO,NO> > tempOutput_ = Xpetra::VectorFactory<double,LO,GO,NO> ::Build(nonUniqueMap);
myWidget.NonUnique2NonUnique(*temp_, *tempOutput_, Xpetra::ADD);
std::vector<bool> gidNotShared(exp_nRows);
{
ArrayRCP<const double> tempOutput = tempOutput_->getData(0);
for (int i = 0; i < exp_nRows; i++) {
if (tempOutput[i] > 1.)
gidNotShared[i] = false;
else
gidNotShared[i] = true;
}
}
// Phase 4.
double nAggregatesTarget;
nAggregatesTarget = ((double) uniqueMap->getGlobalNumElements())* (((double) uniqueMap->getGlobalNumElements())/ ((double) graph.GetGlobalNumEdges()));
GO nAggregatesLocal=nAggregates, nAggregatesGlobal; sumAll(graph.GetComm(), nAggregatesLocal, nAggregatesGlobal);
LO minNAggs; minAll(graph.GetComm(), nAggregates, minNAggs);
LO maxNAggs; maxAll(graph.GetComm(), nAggregates, maxNAggs);
//
// Only do this phase if things look really bad. THIS
// CODE IS PRETTY EXPERIMENTAL
//
#define MUELU_PHASE4BUCKETS 6
if ((nAggregatesGlobal < graph.GetComm()->getSize()) &&
(2.5*nAggregatesGlobal < nAggregatesTarget) &&
(minNAggs ==0) && (maxNAggs <= 1)) {
// Modify seed of the random algorithm used by temp_->randomize()
{
typedef Teuchos::ScalarTraits<double> scalarTrait; // temp_ is of type double.
scalarTrait::seedrandom(static_cast<unsigned int>(myPid*2 + (int) (11*scalarTrait::random())));
int k = (int)ceil( (10.*myPid)/graph.GetComm()->getSize());
for (int i = 0; i < k+7; i++) scalarTrait::random();
temp_->setSeed(static_cast<unsigned int>(scalarTrait::random()));
}
temp_->randomize();
ArrayRCP<double> temp = temp_->getDataNonConst(0);
// build a list of candidate root nodes (vertices not adjacent
// to aggregated vertices)
my_size_t nCandidates = 0;
global_size_t nCandidatesGlobal;
ArrayRCP<LO> candidates = Teuchos::arcp<LO>(nVertices+1);
double priorThreshold = 0.;
for (int kkk = 0; kkk < MUELU_PHASE4BUCKETS; kkk++) {
{
ArrayRCP<const LO> vertex2AggId = aggregates.GetVertex2AggId()->getData(0);
ArrayView<const LO> vertex2AggIdView = vertex2AggId();
RootCandidates(nVertices, vertex2AggIdView, graph, candidates, nCandidates, nCandidatesGlobal);
// views on distributed vectors are freed here.
}
double nTargetNewGuys = nAggregatesTarget - nAggregatesGlobal;
double threshold = priorThreshold + (1. - priorThreshold)*nTargetNewGuys/(nCandidatesGlobal + .001);
threshold = (threshold*(kkk+1.))/((double) MUELU_PHASE4BUCKETS);
priorThreshold = threshold;
{
ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
ArrayRCP<double> weights = distWeights->getDataNonConst(0);
for (int k = 0; k < nCandidates; k++ ) {
int i = candidates[k];
if ((vertex2AggId[i] == MUELU_UNAGGREGATED) && (fabs(temp[i]) < threshold)) {
// Note: priorThreshold <= fabs(temp[i]) <= 1
// neighOfINode is the neighbor node list of node 'iNode'.
ArrayView<const LO> neighOfINode = graph.getNeighborVertices(i);
if (neighOfINode.size() > minNodesPerAggregate) { //TODO: check if this test is exactly was we want to do
int count = 0;
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int Adjacent = *it;
// This might not be true if someone close to i
// is chosen as a root via fabs(temp[]) < Threshold
if (vertex2AggId[Adjacent] == MUELU_UNAGGREGATED){
count++;
vertex2AggId[Adjacent] = nAggregates;
weights[Adjacent] = 1.;
}
}
if (count >= minNodesPerAggregate) {
vertex2AggId[i] = nAggregates++;
weights[i] = 2.;
aggregates.SetIsRoot(i);
}
else { // undo things
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int Adjacent = *it;
if (vertex2AggId[Adjacent] == nAggregates){
vertex2AggId[Adjacent] = MUELU_UNAGGREGATED;
weights[Adjacent] = 0.;
}
}
}
}
}
}
// views on distributed vectors are freed here.
}
//TODO JJH We want to skip this call
myWidget.ArbitrateAndCommunicate(*distWeights, aggregates, true);
// All tentatively assigned vertices are now definitive
nAggregatesLocal=nAggregates;
sumAll(graph.GetComm(), nAggregatesLocal, nAggregatesGlobal);
// check that there are no aggregates sizes below minNodesPerAggregate
aggregates.SetNumAggregates(nAggregates);
RemoveSmallAggs(aggregates, minNodesPerAggregate, distWeights, myWidget);
nAggregates = aggregates.GetNumAggregates();
} // one possibility
}
// Initialize things for Phase 5. This includes building the transpose
// of the matrix ONLY for transposed rows that correspond to unaggregted
// ghost vertices. Further, the transpose is only a local transpose.
// Nonzero edges which exist on other processors are not represented.
int observedNAgg=-1; //number of aggregates that contain vertices on this process
{
ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
ArrayRCP<const LO> procWinner = aggregates.GetProcWinner()->getData(0);
for(LO k = 0; k < vertex2AggId.size(); ++k )
if(vertex2AggId[k]>observedNAgg)
observedNAgg=vertex2AggId[k];
observedNAgg++;
}
ArrayRCP<int> Mark = Teuchos::arcp<int>(exp_nRows+1);
ArrayRCP<int> agg_incremented = Teuchos::arcp<int>(observedNAgg);
ArrayRCP<int> SumOfMarks = Teuchos::arcp<int>(observedNAgg);
for (int i = 0; i < exp_nRows; i++) Mark[i] = MUELU_DISTONE_VERTEX_WEIGHT;
for (int i = 0; i < agg_incremented.size(); i++) agg_incremented[i] = 0;
for (int i = 0; i < SumOfMarks.size(); i++) SumOfMarks[i] = 0;
// Grab the transpose matrix graph for unaggregated ghost vertices.
// a) count the number of nonzeros per row in the transpose
std::vector<int> RowPtr(exp_nRows+1-nVertices);
//{
ArrayRCP<const LO> vertex2AggIdCst = aggregates.GetVertex2AggId()->getData(0);
for (int i = nVertices; i < exp_nRows; i++) RowPtr[i-nVertices] = 0;
for (int i = 0; i < nVertices; i++) {
// neighOfINode is the neighbor node list of node 'iNode'.
ArrayView<const LO> neighOfINode = graph.getNeighborVertices(i);
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int j = *it;
if ( (j >= nVertices) && (vertex2AggIdCst[j] == MUELU_UNAGGREGATED)){
RowPtr[j-nVertices]++;
}
}
}
// b) Convert RowPtr[i] to point to 1st first nnz spot in row i.
int iSum = 0, iTemp;
for (int i = nVertices; i < exp_nRows; i++) {
iTemp = RowPtr[i-nVertices];
RowPtr[i-nVertices] = iSum;
iSum += iTemp;
}
RowPtr[exp_nRows-nVertices] = iSum;
std::vector<LO> cols(iSum+1);
// c) Traverse matrix and insert entries in proper location.
for (int i = 0; i < nVertices; i++) {
// neighOfINode is the neighbor node list of node 'iNode'.
ArrayView<const LO> neighOfINode = graph.getNeighborVertices(i);
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int j = *it;
if ( (j >= nVertices) && (vertex2AggIdCst[j] == MUELU_UNAGGREGATED)){
cols[RowPtr[j-nVertices]++] = i;
}
}
}
// d) RowPtr[i] points to beginning of row i+1 so shift by one location.
for (int i = exp_nRows; i > nVertices; i--)
RowPtr[i-nVertices] = RowPtr[i-1-nVertices];
RowPtr[0] = 0;
// views on distributed vectors are freed here.
vertex2AggIdCst = Teuchos::null;
//}
int bestScoreCutoff;
int thresholds[10] = {300,200,100,50,25,13,7,4,2,0};
// Stick unaggregated vertices into existing aggregates as described above.
{
int ncalls=0;
for (int kk = 0; kk < 10; kk += 2) {
bestScoreCutoff = thresholds[kk];
ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
ArrayRCP<const LO> procWinner = aggregates.GetProcWinner()->getData(0);
ArrayRCP<double> weights = distWeights->getDataNonConst(0);
for (int i = 0; i < exp_nRows; i++) {
if (vertex2AggId[i] == MUELU_UNAGGREGATED) {
// neighOfINode is the neighbor node list of node 'iNode'.
ArrayView<const LO> neighOfINode;
// Grab neighboring vertices which is either in graph for local ids
// or sits in transposed fragment just constructed above for ghosts.
if (i < nVertices) {
neighOfINode = graph.getNeighborVertices(i);
}
else {
LO *rowi_col = NULL, rowi_N;
rowi_col = &(cols[RowPtr[i-nVertices]]);
rowi_N = RowPtr[i+1-nVertices] - RowPtr[i-nVertices];
neighOfINode = ArrayView<const LO>(rowi_col, rowi_N);
}
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int Adjacent = *it;
int AdjacentAgg = vertex2AggId[Adjacent];
//Adjacent is aggregated and either I own the aggregate
// or I could own the aggregate after arbitration.
if ((AdjacentAgg != MUELU_UNAGGREGATED) &&
((procWinner[Adjacent] == myPid) ||
(procWinner[Adjacent] == MUELU_UNASSIGNED))){
SumOfMarks[AdjacentAgg] += Mark[Adjacent];
}
}
int best_score = MUELU_NOSCORE;
int best_agg = -1;
int BestMark = -1;
bool cannotLoseAllFriends=false; // Used to address possible loss of vertices in arbitration of shared nodes discussed above. (Initialized to false only to avoid a compiler warning).
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int Adjacent = *it;
int AdjacentAgg = vertex2AggId[Adjacent];
//Adjacent is unaggregated, has some value and no
//other processor has definitively claimed him
if ((AdjacentAgg != MUELU_UNAGGREGATED) &&
(SumOfMarks[AdjacentAgg] != 0) &&
((procWinner[Adjacent] == myPid) ||
(procWinner[Adjacent] == MUELU_UNASSIGNED ))) {
// first figure out the penalty associated with
// AdjacentAgg having already been incremented
// during this phase, then compute score.
double penalty = (double) (INCR_SCALING*agg_incremented[AdjacentAgg]);
if (penalty > MUELU_PENALTYFACTOR*((double)SumOfMarks[AdjacentAgg]))
penalty = MUELU_PENALTYFACTOR*((double)SumOfMarks[AdjacentAgg]);
int score = SumOfMarks[AdjacentAgg]- ((int) floor(penalty));
if (score > best_score) {
best_agg = AdjacentAgg;
best_score = score;
BestMark = Mark[Adjacent];
cannotLoseAllFriends = false;
// This address issue mentioned above by checking whether
// Adjacent could be lost in arbitration. weight==0 means that
// Adjacent was not set during this loop of Phase 5 (and so it
// has already undergone arbitration). GidNotShared == true
// obviously implies that Adjacent cannot be lost to arbitration
if ((weights[Adjacent]== 0.) || (gidNotShared[Adjacent] == true))
cannotLoseAllFriends = true;
}
// Another vertex within current best aggregate found.
// We should have (best_score == score). We need to see
// if we can improve BestMark and cannotLoseAllFriends.
else if (best_agg == AdjacentAgg) {
if ((weights[Adjacent]== 0.) || (gidNotShared[Adjacent] == true))
cannotLoseAllFriends = true;
if (Mark[Adjacent] > BestMark) BestMark = Mark[Adjacent];
}
}
}
// Clean up
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int Adjacent = *it;
int AdjacentAgg = vertex2AggId[Adjacent];
if (AdjacentAgg >= 0) SumOfMarks[AdjacentAgg] = 0;
}
// Tentatively assign vertex to best_agg.
if ( (best_score >= bestScoreCutoff) && (cannotLoseAllFriends)) {
TEUCHOS_TEST_FOR_EXCEPTION(best_agg == -1 || BestMark == -1, MueLu::Exceptions::RuntimeError, "MueLu::CoupledAggregationFactory internal error"); // should never happen
vertex2AggId[i] = best_agg;
weights[i] = best_score;
agg_incremented[best_agg]++;
Mark[i] = (int) ceil( ((double) BestMark)/2.);
}
}
// views on distributed vectors are freed here.
}
vertex2AggId = Teuchos::null;
procWinner = Teuchos::null;
weights = Teuchos::null;
++ncalls;
//TODO JJH We want to skip this call
myWidget.ArbitrateAndCommunicate(*distWeights, aggregates, true);
// All tentatively assigned vertices are now definitive
}
// if (graph.GetComm()->getRank()==0)
// std::cout << "#calls to Arb&Comm=" << ncalls << std::endl;
}
// Phase 6: Aggregate remain unaggregated vertices and try at all costs
// to avoid small aggregates.
// One case where we can find ourselves in this situation
// is if all vertices vk adjacent to v have already been
// put in other processor's aggregates and v does not have
// a direct connection to a local vertex in any of these
// aggregates.
int Nleftover = 0, Nsingle = 0;
{
ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
ArrayRCP<double> weights = distWeights->getDataNonConst(0);
ArrayRCP<const LO> procWinner = aggregates.GetProcWinner()->getData(0);
int count = 0;
for (my_size_t i = 0; i < nVertices; i++) {
if (vertex2AggId[i] == MUELU_UNAGGREGATED) {
Nleftover++;
// neighOfINode is the neighbor node list of node 'iNode'.
ArrayView<const LO> neighOfINode = graph.getNeighborVertices(i);
// We don't want too small of an aggregate. So lets see if there is an
// unaggregated neighbor that we can also put with this vertex
vertex2AggId[i] = nAggregates;
weights[i] = 1.;
if (count == 0) aggregates.SetIsRoot(i);
count++;
for (typename ArrayView<const LO>::const_iterator it = neighOfINode.begin(); it != neighOfINode.end(); ++it) {
int j = *it;
if ((j != i)&&(vertex2AggId[j] == MUELU_UNAGGREGATED)&&
(j < nVertices)) {
vertex2AggId[j] = nAggregates;
weights[j] = 1.;
count++;
}
}
if ( count >= minNodesPerAggregate) {
nAggregates++;
count = 0;
}
}
}
// We have something which is under minNodesPerAggregate when
if (count != 0) {
#ifdef FIXME
// Can stick small aggregate with 0th aggregate?
if (nAggregates > 0) {
for (my_size_t i = 0; i < nVertices; i++) {
if ((vertex2AggId[i] == nAggregates) && (procWinner[i] == myPid)) {
vertex2AggId[i] = 0;
aggregates.SetIsRoot(i,false);
}
}
}
else {
Nsingle++;
nAggregates++;
}
#else
// Can stick small aggregate with 0th aggregate?
if (nAggregates > 0) {
for (my_size_t i = 0; i < nVertices; i++) {
// TW: This is not a real fix. This may produce ugly bad aggregates!
// I removed the procWinner[i] == myPid check. it makes no sense to me since
// it leaves vertex2AggId[i] == nAggregates -> crash in ComputeAggregateSizes().
// Maybe it's better to add the leftovers to the last generated agg on the current proc.
// The best solution would be to add them to the "next"/nearest aggregate, that may be
// on an other processor
if (vertex2AggId[i] == nAggregates) {
vertex2AggId[i] = nAggregates-1; //0;
aggregates.SetIsRoot(i,false);
}
}
}
else {
Nsingle++;
nAggregates++;
}
#endif
}
// views on distributed vectors are freed here.
}
//TODO JJH We want to skip this call
myWidget.ArbitrateAndCommunicate(*distWeights, aggregates, false);
if (IsPrint(Statistics1)) {
GO total_Nsingle=0; sumAll(graph.GetComm(), (GO)Nsingle, total_Nsingle);
GO total_Nleftover=0; sumAll(graph.GetComm(), (GO)Nleftover, total_Nleftover);
// GO total_aggs; sumAll(graph.GetComm(), (GO)nAggregates, total_aggs);
// GetOStream(Statistics1, 0) << "Phase 6 - total aggregates = " << total_aggs << std::endl;
GetOStream(Statistics1, 0) << "Phase 6 - leftovers = " << total_Nleftover << " and singletons = " << total_Nsingle << std::endl;
}
aggregates.SetNumAggregates(nAggregates);
} //AggregateLeftovers
