Пример #1
0
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();
}
Пример #2
0
/// 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;
}