void spectrum(int i=0) {
  gROOT->SetStyle("Plain");

  TCanvas *c1=new TCanvas("c1","Canvas",600,600);
  gStyle->SetOptStat(0);
  gStyle->SetPalette(1);
  gStyle->SetPadLeftMargin(0.15);
  gStyle->SetPadRightMargin(0.05);
  c1->UseCurrentStyle();

  if(i<4) {
    if(i==0) TFile::Open("summaryDpw.root");
    if(i==1) TFile::Open("summaryNodpw.root");
    if(i==2) TFile::Open("summaryDpw05.root");
    if(i==3) TFile::Open("summaryNodpw05.root");
    
    hDif->SetTitle(";Fraction of charge;Epitaxial layer volume (#mum^{3}/0.01)");
    
    hDif->GetXaxis()->SetRange(0,60);
    //hDif->GetXaxis()->SetTitleOffset(1.1);
    hDif->GetYaxis()->SetTitleOffset(1.8);
    //zAmm0->GetZaxis()->SetRangeUser(0,1.0);
    if(i<2) hDif->GetYaxis()->SetRangeUser(0,8000);
    else    hDif->GetYaxis()->SetRangeUser(0,3000);
    //Trim0Sigmas2D->GetZaxis()->SetRangeUser(0,15);
    
    hDif->SetLineWidth(2);
    hDif->Draw();
    
    hDifC->SetLineWidth(0);
    hDifC->SetFillColor(2);
    hDifC->SetLineColor(2);
    hDifC->Draw("same");
    
    //c1->logy();
    /*
      TH1F hDifO(*hDif);
      hDifO.Add(hDifC,-1.0);
      hDifO.SetLineColor(4);
      hDifO.SetLineStyle(1);
      hDifO.SetLineWidth(2);
      hDifO.Draw("same");
      
      hDif->Draw("same");
    */
    
    c1->Update();
    if(i==0) c1->Print("../dpwSpectrum.png");
    if(i==1) c1->Print("../nodpwSpectrum.png");
    if(i==2) c1->Print("../dpw05Spectrum.png");
    if(i==3) c1->Print("../nodpw05Spectrum.png");

  } else {
    if(i==4) TFile::Open("summaryDpw.root");
    if(i==5) TFile::Open("summaryDpw05.root");

    hDif->SetTitle(";Fraction of charge;Epitaxial layer volume (#mum^{3}/0.01)");
    
    hDif->GetXaxis()->SetRange(26,60);
    hDif->GetYaxis()->SetTitleOffset(1.8);
    if(i==4) hDif->GetYaxis()->SetRangeUser(0,5000);
    if(i==5) hDif->GetYaxis()->SetRangeUser(0,1400);
    
    hDif->SetLineWidth(2);
    hDif->SetLineColor(2);
    hDif->Draw();
    
    if(i==4) TFile::Open("summaryNodpw.root");
    if(i==5) TFile::Open("summaryNodpw05.root");
    
    hDif->SetLineStyle(2);
    hDif->SetLineWidth(2);
    hDif->SetLineColor(4);
    hDif->Draw("same");

    TLatex t;
    t.SetTextSize(0.04);  
    t.SetTextColor(2);
    if(i==4) t.DrawLatex(0.43,4500,"With deep P-well");
    if(i==5) t.DrawLatex(0.43,1200,"With deep P-well");
    t.SetTextColor(4);
    if(i==4) t.DrawLatex(0.43,4200,"Without deep P-well");
    if(i==5) t.DrawLatex(0.43,1100,"Without deep P-well");

    c1->Update();
    if(i==4) c1->Print("../spectra12.png");
    if(i==5) c1->Print("../spectra05.png");
  }
}