void plotDelay(const int istation=1,
	       const int nbinsX = 60,
	       const float minX = 110.5,
	       const float maxX = 170.5,
	       const char *fname="resultDelay160.root"
	       )
{
  TFile *inFile = TFile::Open(fname);

  const int debug = 0;

  // constants for arrays 
  const int kNChan = 32;
  const int kNQR = 26;
  const int kNVRef = 6;
  const int kNACurr = 5;
  const int kNSync = 8;

  TTree *tree = (TTree*) inFile->Get("tree");

  //Declaration of leaves types
  //Declaration of leaves types
  Char_t          filename[200];
  Char_t          datetime[100];
  Char_t          cQR[kNQR];
  Int_t           iChip;
  Int_t           iSta;
  Float_t         fVRef[kNVRef];
  Float_t         fVCurr[kNACurr];
  Float_t         fACurr[kNACurr];
  Float_t         fGain20mV[32];
  Float_t         fGain30mV[32];
  Float_t         fGainRT20mV[32];
  Float_t         fGainRT30mV[32];
  Float_t         fRT20mV[32];
  Float_t         fRT30mV[32];
  Float_t         fPed20mV[32];
  Float_t         fPed30mV[32];
  Float_t         fRms20mV[32];
  Float_t         fRms30mV[32];
  Float_t         fPedAna20mV[32];
  Float_t         fPedAna30mV[32];
  Float_t         fRmsAna20mV[32];
  Float_t         fRmsAna30mV[32];
  Float_t         fX20mVeven;
  Float_t         fX20mVodd;
  Float_t         fX30mVeven;
  Float_t         fX30mVodd;
  Int_t           iSync[kNSync];
  Int_t           iDFT;
  Int_t           iJtag;
  Int_t           iMem;
  Float_t         fRingOsc;
  Int_t           i2cErr;
  Int_t           iErrCode;
  Int_t           iRCode;
  
  // Set branch addresses.
  tree->SetBranchAddress("filename",filename);
  tree->SetBranchAddress("datetime",datetime);
  tree->SetBranchAddress("cQR",&cQR);
  tree->SetBranchAddress("iChip",&iChip);
  tree->SetBranchAddress("iSta",&iSta);
  tree->SetBranchAddress("fVRef",fVRef);
  tree->SetBranchAddress("fVCurr",fVCurr);
  tree->SetBranchAddress("fACurr",fACurr);
  tree->SetBranchAddress("fGain20mV",fGain20mV);
  tree->SetBranchAddress("fGain30mV",fGain30mV);
  tree->SetBranchAddress("fGainRT20mV",fGainRT20mV);
  tree->SetBranchAddress("fGainRT30mV",fGainRT30mV);
  tree->SetBranchAddress("fRT20mV",fRT20mV);
  tree->SetBranchAddress("fRT30mV",fRT30mV);
  tree->SetBranchAddress("fPed20mV",fPed20mV);
  tree->SetBranchAddress("fPed30mV",fPed30mV);
  tree->SetBranchAddress("fRms20mV",fRms20mV);
  tree->SetBranchAddress("fRms30mV",fRms30mV);
  tree->SetBranchAddress("fPedAna20mV",fPedAna20mV);
  tree->SetBranchAddress("fPedAna30mV",fPedAna30mV);
  tree->SetBranchAddress("fRmsAna20mV",fRmsAna20mV);
  tree->SetBranchAddress("fRmsAna30mV",fRmsAna30mV);
  tree->SetBranchAddress("fX20mVeven",&fX20mVeven);
  tree->SetBranchAddress("fX20mVodd",&fX20mVodd);
  tree->SetBranchAddress("fX30mVeven",&fX30mVeven);
  tree->SetBranchAddress("fX30mVodd",&fX30mVodd);
  tree->SetBranchAddress("iSync",iSync);
  tree->SetBranchAddress("iDFT",&iDFT);
  tree->SetBranchAddress("iJtag",&iJtag);
  tree->SetBranchAddress("iMem",&iMem);
  tree->SetBranchAddress("fRingOsc",&fRingOsc);
  tree->SetBranchAddress("i2cErr",&i2cErr);
  tree->SetBranchAddress("iErrCode",&iErrCode);
  tree->SetBranchAddress("iRCode",&iRCode);
  
  //     This is the loop skeleton
  //       To read only selected branches, Insert statements like:
  // tree->SetBranchStatus("*",0);  // disable all branches
  // TTreePlayer->SetBranchStatus("branchname",1);  // activate branchname
  Long64_t nentries = tree->GetEntries();

  // histos: gain20, gain30, rt20, rt30: even & odd 
  const int kNHistMax = 4*2;
  TProfile *hp[kNHistMax];
  TH2F *h2[kNHistMax];

  int nbinsY[kNHistMax] = { 300 };
  float minY[kNHistMax] = { 30.0 };
  float maxY[kNHistMax] = { 33.0 };

  // 
  vector <string> hTitle;
  vector <string> hFill;

  int nHists = 0;
  hTitle.push_back("Gain20 Even (mV/fC)"); nbinsY[nHists] = 300; minY[nHists] = 19.5; maxY[nHists] = 22.5; hFill.push_back("fGain20mVEven"); nHists++;
  hTitle.push_back("Gain30 Even (mV/fC)"); nbinsY[nHists] = 300; minY[nHists] = 30; maxY[nHists] = 33; hFill.push_back("fGain30mVEven"); nHists++;
  hTitle.push_back("RiseTime20mV Even (ns)"); nbinsY[nHists] = 300; minY[nHists] = 60; maxY[nHists] = 75; hFill.push_back("fRT20mVEven"); nHists++;
  hTitle.push_back("RiseTime30mV Even (ns)"); nbinsY[nHists] = 300; minY[nHists] = 60; maxY[nHists] = 75; hFill.push_back("fRT30mVEven"); nHists++;

  hTitle.push_back("Gain20 Odd (mV/fC)"); nbinsY[nHists] = 300; minY[nHists] = 19.5; maxY[nHists] = 22.5; hFill.push_back("fGain20mVOdd"); nHists++;
  hTitle.push_back("Gain30 Odd (mV/fC)"); nbinsY[nHists] = 300; minY[nHists] = 30; maxY[nHists] = 33; hFill.push_back("fGain30mVOdd"); nHists++;
  hTitle.push_back("RiseTime20mV Odd (ns)"); nbinsY[nHists] = 300; minY[nHists] = 60; maxY[nHists] = 75; hFill.push_back("fRT20mVOdd"); nHists++;
  hTitle.push_back("RiseTime30mV Odd (ns)"); nbinsY[nHists] = 300; minY[nHists] = 60; maxY[nHists] = 75; hFill.push_back("fRT30mVOdd"); nHists++;

  if (debug>1) cout << " nHists " << nHists << endl;

  // Print Strings stored in Vector
  if (debug>0) { 
    for (int ii=0; ii<hTitle.size(); ii++) {   
      cout << " ii " << ii << " title " << hTitle[ii] << " - fill " << hFill[ii] << "\n"; 
    }
  }

  int j = 0;
  int k = 0;
  char id[100];
  char fillstr[100];

  // first, create all histos
  for (j = 0; j<nHists; j++) {
    sprintf(id, "h2%d", j);
    h2[j] = new TH2F(id, hTitle[j].c_str(), 
		     nbinsX, minX, maxX,
		     nbinsY[j], minY[j], maxY[j]);

    sprintf(id, "hp%d", j);
    hp[j] = new TProfile(id, hTitle[j].c_str(), 
			 nbinsX, minX, maxX);
  }

  // second, fill all histos
  Long64_t nbytes = 0;
  if (debug>1) cout << " nentries " << nentries << endl;
  for (Long64_t i=0; i<nentries;i++) {
    if (debug>1) cout << " get entry i " << i << endl;
    nbytes += tree->GetEntry(i);
    if (debug>1) cout << " entry i " << i << " iSta " << iSta << endl;

    int delay = iChip;

    if (iSta == istation) { // selected station
      if (debug>1) cout << " selected entry i " << i << " iSta " << iSta << endl;
      int nSyncFail = 0;
      int nSyncOK = 0;
      for (k=0; k<kNSync; k++) {
	if ( (200<iSync[k]) && (iSync[k]<300) ) { nSyncOK++; }
	else { nSyncFail++; }
      }
      if (debug>1) cout << " nSyncOK " << nSyncOK << endl;
      if ( nSyncOK == kNSync ) {
	if (debug>1) cout << " ok entry for station " << iSta << endl;
	
	// need to fill histos in the same order as they were declared above
	j=0;
	if (debug>1) cout << " line " << __LINE__ << " j " << j << endl; 
	
	// all histos with entries per channel
	int oddOffset = 0;
	for (int ichan=0; ichan<32; ichan++) {
	  if (debug>1) cout << " ichan " << ichan << endl;
	  oddOffset = (ichan % 2) * 4;
	  j = oddOffset;
	  h2[j]->Fill(delay, fGain20mV[ichan]); j++;
	  h2[j]->Fill(delay, fGain30mV[ichan]); j++;
	  h2[j]->Fill(delay, fRT20mV[ichan]); j++;
	  h2[j]->Fill(delay, fRT30mV[ichan]); j++;

	  j = oddOffset;
	  hp[j]->Fill(delay, fGain20mV[ichan]); j++;
	  hp[j]->Fill(delay, fGain30mV[ichan]); j++;
	  hp[j]->Fill(delay, fRT20mV[ichan]); j++;
	  hp[j]->Fill(delay, fRT30mV[ichan]); j++;
	}
	if (j != nHists) cerr << " line " << __LINE__ << " mismatch! j " << j << " nHists " << nHists << endl; 
      } // OK event (Sync)
    } // station
  }

  gStyle->SetOptStat(0);
  // third, create all plots, and check cut info 
  if (debug>1) cout << " create canvas " << endl;
  TCanvas *c1 = new TCanvas("c1","c1");
  if (debug>1) cout << " canvas created " << endl;

  for (j = 0; j<nHists; j++) {
    if (debug>1) cout << " line " << __LINE__ << " j " << j << endl; 

    c1->cd(1);
    h2[j]->Draw("colz");
    
    c1->Modified();
    sprintf(id, "png/delay/sta%d_%s.png", istation, hFill[j].c_str());
    c1->SaveAs(id);

    c1->cd(1);
    hp[j]->Draw();
    
    c1->Modified();
    sprintf(id, "png/delay/sta%d_prof_%s.png", istation, hFill[j].c_str());
    c1->SaveAs(id);

  }

}