void TAGMFast::NeighborComInit(const int InitComs) {
//initialize with best neighborhood communities (Gleich et.al. KDD'12)
F.Gen(G->GetNodes());
SumFV.Gen(InitComs);
NumComs = InitComs;
const int Edges = G->GetEdges();
//TIntFltH NCPhiH(F.Len());
TFltIntPrV NIdPhiV(F.Len(), 0);
TIntSet InvalidNIDS(F.Len());
TIntV ChosenNIDV(InitComs, 0); //FOR DEBUG
TExeTm RunTm;
//compute conductance of neighborhood community
for (int u = 0; u < F.Len(); u++) {
TIntSet NBCmty(G->GetNI(u).GetDeg() + 1);
double Phi;
if (G->GetNI(u).GetDeg() < 5) { //do not include nodes with too few degree
Phi = 1.0;
} else {
TAGMUtil::GetNbhCom(G, u, NBCmty);
IAssert(NBCmty.Len() == G->GetNI(u).GetDeg() + 1);
Phi = TAGMUtil::GetConductance(G, NBCmty, Edges);
}
//NCPhiH.AddDat(u, Phi);
NIdPhiV.Add(TFltIntPr(Phi, u));
}
NIdPhiV.Sort(true);
printf("conductance computation completed [%s]\n", RunTm.GetTmStr());
fflush(stdout);
//choose nodes with local minimum in conductance
int CurCID = 0;
for (int ui = 0; ui < NIdPhiV.Len(); ui++) {
int UID = NIdPhiV[ui].Val2;
fflush(stdout);
if (InvalidNIDS.IsKey(UID)) { continue; }
ChosenNIDV.Add(UID); //FOR DEBUG
//add the node and its neighbors to the current community
AddCom(UID, CurCID, 1.0);
TUNGraph::TNodeI NI = G->GetNI(UID);
fflush(stdout);
for (int e = 0; e < NI.GetDeg(); e++) {
AddCom(NI.GetNbrNId(e), CurCID, 1.0);
}
//exclude its neighbors from the next considerations
for (int e = 0; e < NI.GetDeg(); e++) {
InvalidNIDS.AddKey(NI.GetNbrNId(e));
}
CurCID++;
fflush(stdout);
if (CurCID >= NumComs) { break; }
}
if (NumComs > CurCID) {
printf("%d communities needed to fill randomly\n", NumComs - CurCID);
}
//assign a member to zero-member community (if any)
for (int c = 0; c < SumFV.Len(); c++) {
if (SumFV[c] == 0.0) {
int ComSz = 10;
for (int u = 0; u < ComSz; u++) {
int UID = Rnd.GetUniDevInt(G->GetNodes());
AddCom(UID, c, Rnd.GetUniDev());
}
}
}
}
// Initialize node community memberships using best neighborhood communities (see D. Gleich et al. KDD'12).
void TAGMFit::NeighborComInit(const int InitComs) {
CIDNSetV.Gen(InitComs);
const int Edges = G->GetEdges();
TFltIntPrV NIdPhiV(G->GetNodes(), 0);
TIntSet InvalidNIDS(G->GetNodes());
TIntV ChosenNIDV(InitComs, 0); //FOR DEBUG
TExeTm RunTm;
//compute conductance of neighborhood community
TIntV NIdV;
G->GetNIdV(NIdV);
for (int u = 0; u < NIdV.Len(); u++) {
TIntSet NBCmty(G->GetNI(NIdV[u]).GetDeg() + 1);
double Phi;
if (G->GetNI(NIdV[u]).GetDeg() < 5) { //do not include nodes with too few degree
Phi = 1.0;
} else {
TAGMUtil::GetNbhCom(G, NIdV[u], NBCmty);
IAssert(NBCmty.Len() == G->GetNI(NIdV[u]).GetDeg() + 1);
Phi = TAGMUtil::GetConductance(G, NBCmty, Edges);
}
NIdPhiV.Add(TFltIntPr(Phi, NIdV[u]));
}
NIdPhiV.Sort(true);
printf("conductance computation completed [%s]\n", RunTm.GetTmStr());
fflush(stdout);
//choose nodes with local minimum in conductance
int CurCID = 0;
for (int ui = 0; ui < NIdPhiV.Len(); ui++) {
int UID = NIdPhiV[ui].Val2;
fflush(stdout);
if (InvalidNIDS.IsKey(UID)) { continue; }
ChosenNIDV.Add(UID); //FOR DEBUG
//add the node and its neighbors to the current community
CIDNSetV[CurCID].AddKey(UID);
TUNGraph::TNodeI NI = G->GetNI(UID);
fflush(stdout);
for (int e = 0; e < NI.GetDeg(); e++) {
CIDNSetV[CurCID].AddKey(NI.GetNbrNId(e));
}
//exclude its neighbors from the next considerations
for (int e = 0; e < NI.GetDeg(); e++) {
InvalidNIDS.AddKey(NI.GetNbrNId(e));
}
CurCID++;
fflush(stdout);
if (CurCID >= InitComs) { break; }
}
if (InitComs > CurCID) {
printf("%d communities needed to fill randomly\n", InitComs - CurCID);
}
//assign a member to zero-member community (if any)
for (int c = 0; c < CIDNSetV.Len(); c++) {
if (CIDNSetV[c].Len() == 0) {
int ComSz = 10;
for (int u = 0; u < ComSz; u++) {
int UID = G->GetRndNI().GetId();
CIDNSetV[c].AddKey(UID);
}
}
}
InitNodeData();
SetDefaultPNoCom();
}
