Histograms not being written

[Pepe_Le_Pew]

ROOT Primer → File I/O and Parallel Analysis → Storing ROOT Objects
ROOT User’s Guide → Object Ownership

Saving a TGraph in a root file

No idea what you’re talking about: { // open a new ROOT file TFile *f = TFile::Open("MyFile.root", "RECREATE"); // create the graph (in memory) TGraph *g = new TGraph(); for (Int_t i = 0; i < 100; i++) g->SetPoint(g->GetN(), i*i, i*i*i); f->cd(); // make sure that we will write to this ROOT file g->Write("MyGraph"); // save the graph as "MyGraph" f->ls(); // show the contents of the ROOT file delete f; // close the ROOT file g->Draw("A*"); // draw the graph (which is still in…