#include "TVector3.h"
#include "TLorentzVector.h"
#include <iostream>
#include "TFile.h"
#include "TTree.h"
#include "TH2.h"
#include "TF1.h"
#include "TCanvas.h"


void delphes_alanysis() {


    // Open file

 TFile *file = TFile::Open("/home/kanhaiya/Madgraph/MG5_aMC_v2_5_5/new_gghaa/Events/run_02/tag_1_delphes_events.root");
   
    
    if(file==NULL){ // Check if file exist
        printf("File missing!");
        return;
    }
    
 TTree* t = (TTree*)file->Get("Delphes"); // Get the Tree with name
 t->SetMakeClass(1); //<===== important

// Declaration of leaf types

 Int_t Photon_;
 Float_t PT[10000];
 Float_t Eta[10000];
 Float_t Phi[10000];


// List of branches

// TBranch *bpx = t4->GetBranch("fTracks.fPx");
   TBranch *bnphot = t->GetBranch("Photon");
   TBranch *bphot_pt = t->GetBranch("Photon.PT");
   TBranch *bphot_eta = t->GetBranch("Photon.Eta");
   TBranch *bphot_phi = t->GetBranch("Photon.Phi");

   bnphot->SetAddress(&Photon_);
   bphot_pt->SetAddress(PT);
   bphot_eta->SetAddress(Eta);
   bphot_phi->SetAddress(Phi);
  




  // Defining the histograms

  TH1D *new_hist  = new TH1D("new_hist","Histogram", 100, 0. ,200.);


for (Long64_t event=0;event<t->GetEntries();event++) {

     new_hist->Fill(PT[event]);  

}
 
new_hist->Draw();
 

}