#include <map>
#include <RooRealProxy.h>
#include <vector>
#include "RooAbsReal.h"
#include "RooAbsCategory.h"
#include <iostream>
#include <stdlib.h>
#include <RooChebychev.h>
#include <fstream>
#include "TObject.h"
#include "TCut.h"
#include "TH1F.h"
#include "TH2F.h"
#include "TFile.h"
#include "TTree.h"
#include "TPostScript.h"
#include "TCanvas.h"
#include "TNtuple.h"
#include "TChain.h"
#include "TVector3.h"
#include "TLorentzVector.h"
#include "TPaveText.h"
#include "RooAbsPdf.h"
#include "RooFFTConvPdf.h"
#include "RooRealVar.h"
#include "RooNovosibirsk.h"
#include "RooCBShape.h"
#include "RooGaussian.h"
#include "RooChebychev.h"
#include "RooExtendPdf.h"
#include "RooDataSet.h"
#include "RooArgList.h"
#include "RooStats/SPlot.h"
#include "RooAddPdf.h"
#include "RooPlot.h"
#include "RooHist.h"
#include "RooNLLVar.h"
#include "RooMinimizer.h"

using namespace RooFit;

void  example(const char *input_rootname, const char *out_rootname, const char *output_weight,  double Mass_mini, double Mass_maxi){

  // read in mass information
  TChain *chain = new TChain();
  std::string chain_name = std::string(input_rootname)+"/DecayTree";
  chain->Add(chain_name.c_str());  

  double Jpsi_M;
  chain -> SetBranchAddress("Jpsi_DTF_PV_MASS", &Jpsi_M);
       
  std::string mass_low_str = to_string(Mass_mini);
  std::string mass_hig_str = to_string(Mass_maxi);
  string mass_cut = "Jpsi_DTF_PV_MASS>"+mass_low_str+"&&Jpsi_DTF_PV_MASS<"+mass_hig_str;
  TTree* ch_new = chain->CopyTree(mass_cut.c_str());
  cout << "copytree is ok !" <<endl;

  TFile *rootfile  = new TFile(out_rootname,"recreate");
  TTree *DecayTree = new TTree("DecayTree","decay tree");

  DecayTree = ch_new->CloneTree(0);
  double sig_sw;
  std::string out_weight_form = std::string(output_weight) + "/D";
  DecayTree->Branch(output_weight,&sig_sw,out_weight_form.c_str());

  int Number_chain = ch_new->GetEntries();
  for(int i=0;i<Number_chain;i++){
           DecayTree->Fill();
                 }
  cout<<"-----"<<endl;
  rootfile->cd();
  DecayTree->Write();
  rootfile->Close();


}