TFfGGen::TStopReason TFfGGen::AddNodes(const int& GraphNodes, const bool& FloodStop) {
printf("\n***ForestFire: %s Nodes:%d StartNodes:%d Take2AmbProb:%g\n", BurnExpFire ? "ExpFire" : "GeoFire", GraphNodes, StartNodes(), Take2AmbProb());
printf(" FwdBurnP:%g BckBurnP:%g ProbDecay:%g Orphan:%g\n", FwdBurnProb(), BckBurnProb(), ProbDecay(), OrphanProb());
TExeTm ExeTm;
int Burned1 = 0, Burned2 = 0, Burned3 = 0; // last 3 fire sizes
// create initial set of nodes
if (Graph.Empty()) { Graph = PNGraph::New(); }
if (Graph->GetNodes() == 0) {
for (int n = 0; n < StartNodes; n++) { Graph->AddNode(); }
}
int NEdges = Graph->GetEdges();
// forest fire
TRnd Rnd(0);
TForestFire ForestFire(Graph, FwdBurnProb, BckBurnProb, ProbDecay, 0);
// add nodes
for (int NNodes = Graph->GetNodes() + 1; NNodes <= GraphNodes; NNodes++) {
const int NewNId = Graph->AddNode(-1);
IAssert(NewNId == Graph->GetNodes() - 1); // node ids have to be 0...N
// not an Orphan (burn fire)
if (OrphanProb == 0.0 || Rnd.GetUniDev() > OrphanProb) {
// infect ambassadors
if (Take2AmbProb == 0.0 || Rnd.GetUniDev() > Take2AmbProb || NewNId < 2) {
ForestFire.Infect(Rnd.GetUniDevInt(NewNId)); // take 1 ambassador
}
else {
const int AmbassadorNId1 = Rnd.GetUniDevInt(NewNId);
int AmbassadorNId2 = Rnd.GetUniDevInt(NewNId);
while (AmbassadorNId1 == AmbassadorNId2) {
AmbassadorNId2 = Rnd.GetUniDevInt(NewNId);
}
ForestFire.Infect(TIntV::GetV(AmbassadorNId1, AmbassadorNId2)); // take 2 ambassadors
}
// burn fire
if (BurnExpFire) { ForestFire.BurnExpFire(); }
else { ForestFire.BurnGeoFire(); }
// add edges to burned nodes
for (int e = 0; e < ForestFire.GetBurned(); e++) {
Graph->AddEdge(NewNId, ForestFire.GetBurnedNId(e));
NEdges++;
}
Burned1 = Burned2; Burned2 = Burned3; Burned3 = ForestFire.GetBurned();
}
else {
// Orphan (zero out-links)
Burned1 = Burned2; Burned2 = Burned3; Burned3 = 0;
}
if (NNodes % Kilo(1) == 0) {
printf("(%d, %d) burned: [%d,%d,%d] [%s]\n", NNodes, NEdges, Burned1, Burned2, Burned3, ExeTm.GetStr());
}
if (FloodStop && NEdges>GraphNodes && (NEdges / double(NNodes)>1000.0)) { // average node degree is more than 500
printf(". FLOOD. G(%6d, %6d)\n", NNodes, NEdges); return srFlood;
}
if (NNodes % 1000 == 0 && TimeLimitSec > 0 && ExeTm.GetSecs() > TimeLimitSec) {
printf(". TIME LIMIT. G(%d, %d)\n", Graph->GetNodes(), Graph->GetEdges());
return srTimeLimit;
}
}
IAssert(Graph->GetEdges() == NEdges);
return srOk;
}
int main(int argc, char* argv[]) {
// create a graph and save it
{ PNGraph Graph = TNGraph::New();
for (int i = 0; i < 10; i++) {
Graph->AddNode(i); }
for (int i = 0; i < 10; i++) {
Graph->AddEdge(i, TInt::Rnd.GetUniDevInt(10)); }
TSnap::SaveEdgeList(Graph, "graph.txt", "Edge list format"); }
// load a graph
PNGraph Graph;
Graph = TSnap::LoadEdgeList<PNGraph>("graph.txt", 0, 1);
// traverse nodes
for (TNGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
printf("NodeId: %d, InDegree: %d, OutDegree: %d\n", NI.GetId(), NI.GetInDeg(), NI.GetOutDeg());
printf("OutNodes: ");
for (int e = 0; e < NI.GetOutDeg(); e++) { printf(" %d", NI.GetOutNId(e)); }
printf("\nInNodes: ");
for (int e = 0; e < NI.GetInDeg(); e++) { printf(" %d", NI.GetInNId(e)); }
printf("\n\n");
}
// graph statistic
TSnap::PrintInfo(Graph, "Graph info");
PNGraph MxWcc = TSnap::GetMxWcc(Graph);
TSnap::PrintInfo(MxWcc, "Largest Weakly connected component");
// random graph
PNGraph RndGraph = TSnap::GenRndGnm<PNGraph>(100, 1000);
TGStat GraphStat(RndGraph, TSecTm(1), TGStat::AllStat(), "Gnm graph");
GraphStat.PlotAll("RndGraph", "Random graph on 1000 nodes");
// Forest Fire graph
{ TFfGGen ForestFire(false, 1, 0.35, 0.30, 1.0, 0.0, 0.0);
ForestFire.GenGraph(100);
PNGraph FfGraph = ForestFire.GetGraph(); }
// network
TPt<TNodeEDatNet<TStr, TStr> > Net = TNodeEDatNet<TStr, TStr>::New();
Net->AddNode(0, "zero");
Net->AddNode(1, "one");
Net->AddEdge(0, 1, "zero to one");
return 0;
}
