void an(TString filename = "data.root"){

TFile* file = TFile::Open(filename);
if(file){
	cout <<"*************************************"<<endl;
	cout <<" File have been opend successfully!!"<<endl;
        cout <<"*************************************"<<endl;
}
TTree* tree = (TTree*)file->Get("ntuple");
if(!tree)cout<<" Cannot find the tree successfully!!"<<endl;

int nEntries = tree->GetEntriesFast();
cout << " Entries number is  "<<nEntries <<endl;
//--------------------------------------------------------
Bool_t cfdft;                    TBranch* t_cfdft;
Short_t ltra = 0;                TBranch* t_ltra; 
Short_t wave[5000] = {0};        TBranch* t_data;
Short_t evte = 0;                TBranch* t_evte; 
Bool_t pileup;                   TBranch* t_pileup; 


tree->SetBranchAddress("ltra",&ltra,&t_ltra);
tree->SetBranchAddress("cfdft",&cfdft,&t_cfdft);
tree->SetBranchAddress("data",&wave,&t_data);
tree->SetBranchAddress("evte",&evte,&t_evte);
tree->SetBranchAddress("pileup",&pileup,&t_pileup);
//---------------------------------------------------------
Int_t npeaks = 30;
Int_t TwoPeakNum = 0;
Int_t sumNum,sumN;

//---------------------------------------------------------
 TGraph* gr = new TGraph(); TGraph* gr_copy = new TGraph();
 TGraph* singleWave = new TGraph();
 TH1F* waveHist = new TH1F("single wave","single wave",5000,0,5000);
 TH1F* base = new TH1F("baseline","baseline",100,1600,1700);//baseline

//TCanvas* myc = new TCanvas("dynamic wave anayzed","",700,500);
//-------------------------------------------------------------------------
  for(int entry = 0;entry < nEntries;entry++){
         
         waveHist->Reset(); 
     
     tree->GetEntry(entry);   
     
     sumNum = sumN = 0; 
          
  if(pileup==1)continue;
    if(evte<=4000)continue;
  if(entry % 100 ==0) cout <<entry << "  have been analyzed!!"<<endl;
  
       for(Int_t i=0; i<ltra; i++){
             gr->SetPoint(i,i,wave[i]);
             waveHist->SetBinContent(i+1,wave[i]);  
             if(entry == 6)singleWave->SetPoint(i,i,wave[i]);    
     } 
  
 /*     myc->cd();
    gr->SetMarkerColor(kRed);
    gr->SetMarkerStyle(8);
    gr->SetMarkerSize(0.5);
    gr->Draw("AP");
    gr->SetTitle(Form("%d",entry));
    myc->Modified();
    myc->Update();
	  gSystem->Sleep(1000); //1s
	  gSystem->ProcessEvents();
 */
 
    TSpectrum *s = new TSpectrum(2*npeaks);
   Int_t nfound = s->Search(waveHist,2,"",0.01); 
                   //-------------------------------------// 
                   //            find peaks               // 
                   //-------------------------------------//
          TGraph* graph = new TGraph();
 if(nfound == 2) {
    
         for(int i=0;i<ltra;i++){
                 if(wave[i]<1700)wave[i]=0;
                    graph->SetPoint(i,i,wave[i]);                       
             }

  TwoPeakNum++;  
 }
 
 
  }

TCanvas* canvas1 = new TCanvas("canvas","canvas",700,500);
canvas1->cd();
    singleWave->SetMarkerColor(kBlue);
    singleWave->SetMarkerStyle(8);
    singleWave->SetMarkerSize(0.5);
    singleWave->SetTitle("signle;time(ns);amplitude");
    singleWave->GetXaxis()->CenterTitle();
    singleWave->GetYaxis()->CenterTitle();
singleWave->Draw("AP");

}