/// estimate number of communities using cross validation
int TAGMFast::FindComsByCV(const int NumThreads, const int MaxComs, const int MinComs, const int DivComs, const TStr OutFNm, const double StepAlpha, const double StepBeta) {
double ComsGap = exp(TMath::Log((double) MaxComs / (double) MinComs) / (double) DivComs);
TIntV ComsV;
ComsV.Add(MinComs);
while (ComsV.Len() < DivComs) {
int NewComs = int(ComsV.Last() * ComsGap);
if (NewComs == ComsV.Last().Val) { NewComs++; }
ComsV.Add(NewComs);
}
if (ComsV.Last() < MaxComs) { ComsV.Add(MaxComs); }
return FindComsByCV(ComsV, 0.1, NumThreads, OutFNm + ".CV.likelihood", StepAlpha, StepBeta);
}
/// rewire bipartite community affiliation graphs
void TAGMUtil::RewireCmtyNID(THash<TInt,TIntV >& CmtyVH, TRnd& Rnd) {
THash<TInt,TIntV > NewCmtyVH(CmtyVH.Len());
TIntV NDegV;
TIntV CDegV;
for (int i = 0; i < CmtyVH.Len(); i++) {
int CID = CmtyVH.GetKey(i);
for (int j = 0; j < CmtyVH[i].Len(); j++) {
int NID = CmtyVH[i][j];
NDegV.Add(NID);
CDegV.Add(CID);
}
}
TIntPrSet CNIDSet(CDegV.Len());
int c=0;
while (c++ < 15 && CDegV.Len() > 1) {
for (int i = 0; i < CDegV.Len(); i++) {
int u = Rnd.GetUniDevInt(CDegV.Len());
int v = Rnd.GetUniDevInt(NDegV.Len());
if (CNIDSet.IsKey(TIntPr(CDegV[u], NDegV[v]))) {
continue;
}
CNIDSet.AddKey(TIntPr(CDegV[u], NDegV[v]));
if (u == CDegV.Len() - 1) {
CDegV.DelLast();
} else {
CDegV[u] = CDegV.Last();
CDegV.DelLast();
}
if ( v == NDegV.Len() - 1) {
NDegV.DelLast();
} else {
NDegV[v] = NDegV.Last();
NDegV.DelLast();
}
}
}
for (int i = 0; i < CNIDSet.Len(); i++) {
TIntPr CNIDPr = CNIDSet[i];
IAssert(CmtyVH.IsKey(CNIDPr.Val1));
NewCmtyVH.AddDat(CNIDPr.Val1);
NewCmtyVH.GetDat(CNIDPr.Val1).Add(CNIDPr.Val2);
}
CmtyVH = NewCmtyVH;
}
//Precompute unigram table using alias sampling method
void InitUnigramTable(TIntV& Vocab, TIntV& KTable, TFltV& UTable) {
double TrainWordsPow = 0;
double Pwr = 0.75;
TFltV ProbV(Vocab.Len());
for (int64 i = 0; i < Vocab.Len(); i++) {
ProbV[i]=TMath::Power(Vocab[i],Pwr);
TrainWordsPow += ProbV[i];
KTable[i]=0;
UTable[i]=0;
}
for (int64 i = 0; i < ProbV.Len(); i++) {
ProbV[i] /= TrainWordsPow;
}
TIntV UnderV;
TIntV OverV;
for (int64 i = 0; i < ProbV.Len(); i++) {
UTable[i] = ProbV[i] * ProbV.Len();
if ( UTable[i] < 1 ) {
UnderV.Add(i);
} else {
OverV.Add(i);
}
}
while(UnderV.Len() > 0 && OverV.Len() > 0) {
int64 Small = UnderV.Last();
int64 Large = OverV.Last();
UnderV.DelLast();
OverV.DelLast();
KTable[Small] = Large;
UTable[Large] = UTable[Large] + UTable[Small] - 1;
if (UTable[Large] < 1) {
UnderV.Add(Large);
} else {
OverV.Add(Large);
}
}
}
void TBlobBs::GenBlockLenV(TIntV& BlockLenV){
BlockLenV.Clr();
for (int P2Exp=0; P2Exp<TB4Def::MxP2Exp; P2Exp++){
BlockLenV.Add(TInt(TB4Def::GetP2(P2Exp)));}
EAssert(int(BlockLenV.Last())<2000000000);
{for (int Len=10; Len<100; Len+=10){BlockLenV.Add(Len);}}
{for (int Len=100; Len<10000; Len+=100){BlockLenV.Add(Len);}}
{for (int Len=10000; Len<100000; Len+=1000){BlockLenV.Add(Len);}}
{for (int Len=100000; Len<1000000; Len+=25000){BlockLenV.Add(Len);}}
{for (int Len=1000000; Len<10000000; Len+=1000000){BlockLenV.Add(Len);}}
{for (int Len=10000000; Len<100000000; Len+=10000000){BlockLenV.Add(Len);}}
BlockLenV.Sort();
}
int TAGMFast::FindComsByCV(TIntV& ComsV, const double HOFrac, const int NumThreads, const TStr PlotLFNm, const double StepAlpha, const double StepBeta) {
if (ComsV.Len() == 0) {
int MaxComs = G->GetNodes() / 5;
ComsV.Add(2);
while(ComsV.Last() < MaxComs) { ComsV.Add(ComsV.Last() * 2); }
}
TIntPrV EdgeV(G->GetEdges(), 0);
for (TUNGraph::TEdgeI EI = G->BegEI(); EI < G->EndEI(); EI++) {
EdgeV.Add(TIntPr(EI.GetSrcNId(), EI.GetDstNId()));
}
EdgeV.Shuffle(Rnd);
int MaxIterCV = 3;
TVec<TVec<TIntSet> > HoldOutSets(MaxIterCV);
if (EdgeV.Len() > 50) { //if edges are many enough, use CV
printf("generating hold out set\n");
TIntV NIdV1, NIdV2;
G->GetNIdV(NIdV1);
G->GetNIdV(NIdV2);
for (int IterCV = 0; IterCV < MaxIterCV; IterCV++) {
// generate holdout sets
HoldOutSets[IterCV].Gen(G->GetNodes());
const int HOTotal = int(HOFrac * G->GetNodes() * (G->GetNodes() - 1) / 2.0);
int HOCnt = 0;
int HOEdges = (int) TMath::Round(HOFrac * G->GetEdges());
printf("holding out %d edges...\n", HOEdges);
for (int he = 0; he < (int) HOEdges; he++) {
HoldOutSets[IterCV][EdgeV[he].Val1].AddKey(EdgeV[he].Val2);
HoldOutSets[IterCV][EdgeV[he].Val2].AddKey(EdgeV[he].Val1);
HOCnt++;
}
printf("%d Edges hold out\n", HOCnt);
while(HOCnt++ < HOTotal) {
int SrcNID = Rnd.GetUniDevInt(G->GetNodes());
int DstNID = Rnd.GetUniDevInt(G->GetNodes());
HoldOutSets[IterCV][SrcNID].AddKey(DstNID);
HoldOutSets[IterCV][DstNID].AddKey(SrcNID);
}
}
printf("hold out set generated\n");
}
TFltV HOLV(ComsV.Len());
TIntFltPrV ComsLV;
for (int c = 0; c < ComsV.Len(); c++) {
const int Coms = ComsV[c];
printf("Try number of Coms:%d\n", Coms);
NeighborComInit(Coms);
printf("Initialized\n");
if (EdgeV.Len() > 50) { //if edges are many enough, use CV
for (int IterCV = 0; IterCV < MaxIterCV; IterCV++) {
HOVIDSV = HoldOutSets[IterCV];
if (NumThreads == 1) {
printf("MLE without parallelization begins\n");
MLEGradAscent(0.05, 10 * G->GetNodes(), "", StepAlpha, StepBeta);
} else {
printf("MLE with parallelization begins\n");
MLEGradAscentParallel(0.05, 100, NumThreads, "", StepAlpha, StepBeta);
}
double HOL = LikelihoodHoldOut();
HOL = HOL < 0? HOL: TFlt::Mn;
HOLV[c] += HOL;
}
}
else {
HOVIDSV.Gen(G->GetNodes());
MLEGradAscent(0.0001, 100 * G->GetNodes(), "");
double BIC = 2 * Likelihood() - (double) G->GetNodes() * Coms * 2.0 * log ( (double) G->GetNodes());
HOLV[c] = BIC;
}
}
int EstComs = 2;
double MaxL = TFlt::Mn;
printf("\n");
for (int c = 0; c < ComsV.Len(); c++) {
ComsLV.Add(TIntFltPr(ComsV[c].Val, HOLV[c].Val));
printf("%d(%f)\t", ComsV[c].Val, HOLV[c].Val);
if (MaxL < HOLV[c]) {
MaxL = HOLV[c];
EstComs = ComsV[c];
}
}
printf("\n");
RandomInit(EstComs);
HOVIDSV.Gen(G->GetNodes());
if (! PlotLFNm.Empty()) {
TGnuPlot::PlotValV(ComsLV, PlotLFNm, "hold-out likelihood", "communities", "likelihood");
}
return EstComs;
}