void TTop2FriendNet::GetAvgSDevV(const THash<TFlt, TMom>& MomH, TFltTrV& ValAvgSDevV) {
ValAvgSDevV.Clr(false);
for (int i = 0; i < MomH.Len(); i++) {
TMom Mom=MomH[i];
Mom.Def();
ValAvgSDevV.Add(TFltTr(MomH.GetKey(i), Mom.GetMean(), Mom.GetSDev()));
}
ValAvgSDevV.Sort();
}
/// Generates a random scale-free graph using the Geometric Preferential
/// Attachment model by Flexman, Frieze and Vera.
/// See: A geometric preferential attachment model of networks by Flexman,
/// Frieze and Vera. WAW 2004.
/// URL: http://math.cmu.edu/~af1p/Texfiles/GeoWeb.pdf
PUNGraph GenGeoPrefAttach(const int& Nodes, const int& OutDeg, const double& Beta, TRnd& Rnd) {
PUNGraph G = TUNGraph::New(Nodes, Nodes*OutDeg);
TFltTrV PointV(Nodes, 0);
TFltV ValV;
// points on a sphere of radius 1/(2*pi)
const double Rad = 0.5 * TMath::Pi;
for (int i = 0; i < Nodes; i++) {
TSnapDetail::GetSphereDev(3, Rnd, ValV);
PointV.Add(TFltTr(Rad*ValV[0], Rad*ValV[1], Rad*ValV[2]));
}
const double R2 = TMath::Sqr(log((double) Nodes) / (pow((double) Nodes, 0.5-Beta)));
TIntV DegV, NIdV;
int SumDeg;
for (int t = 0; t < Nodes; t++) {
const int pid = t;
const TFltTr& P1 = PointV[pid];
// add node
if (! G->IsNode(pid)) { G->AddNode(pid); }
// find neighborhood
DegV.Clr(false); NIdV.Clr(false); SumDeg=0;
for (int p = 0; p < t; p++) {
const TFltTr& P2 = PointV[p];
if (TMath::Sqr(P1.Val1-P2.Val1)+TMath::Sqr(P1.Val2-P2.Val2)+TMath::Sqr(P1.Val3-P2.Val3) < R2) {
NIdV.Add(p);
DegV.Add(G->GetNI(p).GetDeg()+1);
SumDeg += DegV.Last();
}
}
// add edges
for (int m = 0; m < OutDeg; m++) {
const int rnd = Rnd.GetUniDevInt(SumDeg);
int sum = 0, dst = -1;
for (int s = 0; s < DegV.Len(); s++) {
sum += DegV[s];
if (rnd < sum) { dst=s; break; }
}
if (dst != -1) {
G->AddEdge(pid, NIdV[dst]);
SumDeg -= DegV[dst];
NIdV.Del(dst); DegV.Del(dst);
}
}
}
return G;
}
