using namespace std;
using namespace TMath;

void Main(){
  TFile *in = new TFile("EfficiencyResults.root");
  TTree *tree = (TTree*)in->Get("Efficiency");

  double entries, eff, sig1, count, sig2;
  tree->SetBranchAddress("Entries",&entries);
  tree->SetBranchAddress("Efficiency",&eff);
  tree->SetBranchAddress("Eff_Sigma",&sig1);
  tree->SetBranchAddress("Counts",&count);
  tree->SetBranchAddress("Counts_Sigma",&sig2);

  const int ds = tree->GetEntries();

  double hent[ds], hcount[ds], hsig[ds], hex[ds];

  for(int i = 0; i<ds; i++){
    tree->GetEntry(i);
    hent[i] = entries;
    hcount[i] = count;
    hsig[i] = sig2/Sqrt(40);
    hex[i] = 0;
  }

  TGraphErrors *g = new TGraphErrors(ds,hent,hcount,hex,hsig);
  g->Fit("pol1");
  g->GetYaxis()->SetTitle("Counts");
  g->GetXaxis()->SetTitle("Signal");
  g->SetMarkerColor(kBlue);
  g->SetMarkerStyle(20);
  g->Draw("ALP RX");
  gPad->Update();
}