/// Returns the ID of the neighbor that \c NId pushes to, -1 if no push was made.
int PushRelabel (TPRManager &PRM, const int &NId, const TNEANet::TNodeI &NI) {
int EdgeN = PRM.EdgeNum(NId);
int EId = -1, NbrNId = -1, ResFlow = 0;
int Cutoff = NI.GetInDeg();
if (EdgeN < Cutoff) {
EId = NI.GetInEId(EdgeN);
NbrNId = NI.GetInNId(EdgeN);
ResFlow = PRM.Flow(EId);
} else {
EId = NI.GetOutEId(EdgeN - Cutoff);
NbrNId = NI.GetOutNId(EdgeN - Cutoff);
ResFlow = PRM.Capacity(EId) - PRM.Flow(EId);
}
if (ResFlow > 0 && PRM.Label(NId) - 1 == PRM.Label(NbrNId)) {
if (EdgeN < Cutoff) {
PushToInNbr(PRM, NId, NbrNId, EId);
} else {
PushToOutNbr(PRM, NId, NbrNId, EId);
}
return NbrNId;
}
if (EdgeN + 1 == NI.GetDeg()) {
PRM.EdgeNum(NId) = 0;
Relabel(PRM, NId, NI);
} else {
PRM.EdgeNum(NId)++;
}
return -1;
}
int GetWeightedPageRankMP1(const PNEANet Graph, TIntFltH& PRankH, const TStr& Attr, const double& C, const double& Eps, const int& MaxIter) {
if (!Graph->IsFltAttrE(Attr)) return -1;
TFltV Weights = Graph->GetFltAttrVecE(Attr);
int mxid = Graph->GetMxNId();
TFltV OutWeights(mxid);
Graph->GetWeightOutEdgesV(OutWeights, Weights);
/*for (TNEANet::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
OutWeights[NI.GetId()] = Graph->GetWeightOutEdges(NI, Attr);
}*/
/*TIntFltH Weights;
for (TNEANet::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
Weights.AddDat(NI.GetId(), Graph->GetWeightOutEdges(NI, Attr));
}*/
const int NNodes = Graph->GetNodes();
TVec<TNEANet::TNodeI> NV;
//const double OneOver = 1.0/double(NNodes);
PRankH.Gen(NNodes);
for (TNEANet::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
NV.Add(NI);
PRankH.AddDat(NI.GetId(), 1.0/NNodes);
//IAssert(NI.GetId() == PRankH.GetKey(PRankH.Len()-1));
}
TFltV TmpV(NNodes);
for (int iter = 0; iter < MaxIter; iter++) {
#pragma omp parallel for schedule(dynamic,10000)
for (int j = 0; j < NNodes; j++) {
TNEANet::TNodeI NI = NV[j];
TmpV[j] = 0;
for (int e = 0; e < NI.GetInDeg(); e++) {
const int InNId = NI.GetInNId(e);
const TFlt OutWeight = OutWeights[InNId];
int EId = Graph->GetEId(InNId, NI.GetId());
const TFlt Weight = Weights[Graph->GetFltKeyIdE(EId)];
if (OutWeight > 0) {
TmpV[j] += PRankH.GetDat(InNId) * Weight / OutWeight; }
}
TmpV[j] = C*TmpV[j]; // Berkhin (the correct way of doing it)
//TmpV[j] = C*TmpV[j] + (1.0-C)*OneOver; // iGraph
}
double diff=0, sum=0, NewVal;
#pragma omp parallel for reduction(+:sum) schedule(dynamic,10000)
for (int i = 0; i < TmpV.Len(); i++) { sum += TmpV[i]; }
const double Leaked = (1.0-sum) / double(NNodes);
#pragma omp parallel for reduction(+:diff) schedule(dynamic,10000)
for (int i = 0; i < PRankH.Len(); i++) { // re-instert leaked PageRank
NewVal = TmpV[i] + Leaked; // Berkhin
//NewVal = TmpV[i] / sum; // iGraph
diff += fabs(NewVal-PRankH[i]);
PRankH[i] = NewVal;
}
if (diff < Eps) { break; }
}
return 0;
}
/// Increases the label of a node \c NId to allow valid pushes to some neighbor.
void Relabel (TPRManager &PRM, const int &NId, const TNEANet::TNodeI &NI) {
int MaxLabel = PRM.GetMaxLabel();
int MinLabel = MaxLabel;
for (int EdgeN = 0; EdgeN < NI.GetInDeg(); EdgeN++) {
if (PRM.Flow(NI.GetInEId(EdgeN)) > 0) {
int InLabel = PRM.Label(NI.GetInNId(EdgeN));
MinLabel = min(MinLabel, InLabel);
}
}
for (int EdgeN = 0; EdgeN < NI.GetOutDeg(); EdgeN++) {
if (PRM.Capacity(NI.GetOutEId(EdgeN)) > PRM.Flow(NI.GetOutEId(EdgeN))) {
int OutLabel = PRM.Label(NI.GetOutNId(EdgeN));
MinLabel = min(MinLabel, OutLabel);
}
}
if (MinLabel == MaxLabel) {
PRM.SetLabel(NId, MaxLabel);
} else {
PRM.SetLabel(NId, MinLabel + 1);
}
}
int GetWeightedPageRankMP2(const PNEANet Graph, TIntFltH& PRankH, const TStr& Attr, const double& C, const double& Eps, const int& MaxIter) {
if (!Graph->IsFltAttrE(Attr)) return -1;
const int NNodes = Graph->GetNodes();
TVec<TNEANet::TNodeI> NV;
//const double OneOver = 1.0/double(NNodes);
PRankH.Gen(NNodes);
int MxId;
for (TNEANet::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
NV.Add(NI);
PRankH.AddDat(NI.GetId(), 1.0/NNodes);
int Id = NI.GetId();
if (Id > MxId) {
MxId = Id;
}
}
TFltV PRankV(MxId+1);
TFltV OutWeights(MxId+1);
TFltV Weights = Graph->GetFltAttrVecE(Attr);
#pragma omp parallel for schedule(dynamic,10000)
for (int j = 0; j < NNodes; j++) {
TNEANet::TNodeI NI = NV[j];
int Id = NI.GetId();
OutWeights[Id] = Graph->GetWeightOutEdges(NI, Attr);
PRankV[Id] = 1/NNodes;
}
TFltV TmpV(NNodes);
for (int iter = 0; iter < MaxIter; iter++) {
#pragma omp parallel for schedule(dynamic,10000)
for (int j = 0; j < NNodes; j++) {
TNEANet::TNodeI NI = NV[j];
TFlt Tmp = 0;
for (int e = 0; e < NI.GetInDeg(); e++) {
const int InNId = NI.GetInNId(e);
const TFlt OutWeight = OutWeights[InNId];
int EId = Graph->GetEId(InNId, NI.GetId());
const TFlt Weight = Weights[Graph->GetFltKeyIdE(EId)];
if (OutWeight > 0) {
Tmp += PRankH.GetDat(InNId) * Weight / OutWeight;
}
}
TmpV[j] = C*Tmp; // Berkhin (the correct way of doing it)
//TmpV[j] = C*TmpV[j] + (1.0-C)*OneOver; // iGraph
}
double sum = 0;
#pragma omp parallel for reduction(+:sum) schedule(dynamic,10000)
for (int i = 0; i < TmpV.Len(); i++) { sum += TmpV[i]; }
const double Leaked = (1.0-sum) / double(NNodes);
double diff = 0;
#pragma omp parallel for reduction(+:diff) schedule(dynamic,10000)
for (int i = 0; i < NNodes; i++) {
TNEANet::TNodeI NI = NV[i];
double NewVal = TmpV[i] + Leaked; // Berkhin
//NewVal = TmpV[i] / sum; // iGraph
int Id = NI.GetId();
diff += fabs(NewVal-PRankV[Id]);
PRankV[Id] = NewVal;
}
if (diff < Eps) { break; }
}
#pragma omp parallel for schedule(dynamic,10000)
for (int i = 0; i < NNodes; i++) {
TNEANet::TNodeI NI = NV[i];
PRankH[i] = PRankV[NI.GetId()];
}
return 0;
}
