void RootTutorial1_sol() {

  // Get the data file
  cout << "[root_tutorial_1] Getting data file!" << endl;
  TFile *f = new TFile("../zjet.root");
  // Get the tree from the file
  cout << "[root_tutorial_1] Getting TTree from file" << endl;
  TTree *t = (TTree*)f->Get( "Tdata" );
  
  // Create a 1D histogram
  cout << "[root_tutorial_1] Creating histogram object (TH1F)" << endl;

  //Change bin to 300
  //TH1F *h_px = new TH1F("h_px","An Histogram",300,0,150);
  TH1F *h_px = new TH1F("h_px","An Histogram",300,89.5, 92.5);
  
  
  h_px->SetFillColor(4);
  h_px->SetLineColor(2);
  
  // Fill the histogram using information from the "px" branch from the tree
  cout << "[root_tutorial_1] Filling histogram and drawing it" << endl;
  t->Draw("m>>h_px", "id==0");
  

  Double_t factor = 1.;
  h_px->Rebin(2);

  // Scale by factor equal to Area
  h_px->Scale(factor/h_px->Integral());
  h_px->Sumw2(0);

  h_px->Fit("gaus");
  h_px->SetTitle("Chaging title");
  
  // You'll see some tails corresponding to a Lorentzian distributions...
  // The gaussian fit is not quite the best approach... 
  // Adjust the boundaries of the fit

  TF1 *g = (TF1*)h_px->GetListOfFunctions()->FindObject("gaus");

  //Extract the parameters
  double constant = g->GetParameter(0);
  double mean = g->GetParameter(1);
  double sigma = g->GetParameter(2);

  cout << "Results: "<< constant << " " << mean << " " << sigma << endl;

}