[u/mrichter/AliRoot.git] / PWG0 / dNdEta / dNdEtaAnalysis.cxx

/* $Id$ */

#include "dNdEtaAnalysis.h"

#include <TFile.h>
#include <TH2F.h>
#include <TH1D.h>
#include <TMath.h>
#include <TCanvas.h>
#include <TCollection.h>
#include <TIterator.h>
#include <TList.h>
#include <TLegend.h>

#include "dNdEtaCorrection.h"

//____________________________________________________________________
ClassImp(dNdEtaAnalysis)

//____________________________________________________________________
dNdEtaAnalysis::dNdEtaAnalysis(Char_t* name, Char_t* title) :
TNamed(name, title)
{
  hEtaVsVtx  = new TH2F(Form("%s_eta_vs_vtx", name),"",80,-20,20,120,-6,6);
  hEtaVsVtx->SetXTitle("vtx z [cm]");
  hEtaVsVtx->SetYTitle("#eta");

  hEtaVsVtxUncorrected = dynamic_cast<TH2F*> (hEtaVsVtx->Clone(Form("%s_eta_vs_vtx_uncorrected", name)));
  hEtaVsVtxCheck = dynamic_cast<TH2F*> (hEtaVsVtx->Clone(Form("%s_eta_vs_vtx_check", name)));
  hVtx       = hEtaVsVtx->ProjectionX(Form("%s_vtx", name));
  for (Int_t i=0; i<kVertexBinning; ++i)
  {
    hdNdEta[i]    = hEtaVsVtx->ProjectionY(Form("%s_dNdEta_%d", name, i));
    hdNdEta[i]->SetYTitle("dN/d#eta");
  }

  hEtaVsVtx->Sumw2();
  hVtx->Sumw2();
}

//____________________________________________________________________
void
dNdEtaAnalysis::FillTrack(Float_t vtx, Float_t eta, Float_t c) {
  hEtaVsVtxUncorrected->Fill(vtx,eta);
  hEtaVsVtxCheck->Fill(vtx, eta, c);
}

//____________________________________________________________________
void
dNdEtaAnalysis::FillEvent(Float_t vtx) {
  hVtx->Fill(vtx);
}

//____________________________________________________________________
void dNdEtaAnalysis::Finish(dNdEtaCorrection* correction)
{
  // correct with correction values if available
  // TODO what do we do with the error?
  if (!correction)
    printf("INFO: No correction applied\n");

  // this can be replaced by TH2F::Divide if we agree that the binning will be always the same
  for (Int_t iVtx=0; iVtx<=hEtaVsVtxUncorrected->GetNbinsX(); iVtx++)
  {
    for (Int_t iEta=0; iEta<=hEtaVsVtxUncorrected->GetNbinsY(); iEta++)
    {
      Float_t correctionValue = 1;
      if (correction)
        correctionValue = correction->GetCorrection(hEtaVsVtxUncorrected->GetXaxis()->GetBinCenter(iVtx), hEtaVsVtxUncorrected->GetYaxis()->GetBinCenter(iEta));

      Float_t value = hEtaVsVtxUncorrected->GetBinContent(iVtx, iEta);
      Float_t error = hEtaVsVtxUncorrected->GetBinError(iVtx, iEta);

      Float_t correctedValue = value * correctionValue;
      Float_t correctedError = error * correctionValue;

      if (correctedValue != 0)
      {
        hEtaVsVtx->SetBinContent(iVtx, iEta, correctedValue);
        hEtaVsVtx->SetBinError(iVtx, iEta, correctedError);
      }
    }
  }

  // normalize with n events (per vtx)
  for (Int_t iVtx=0; iVtx<=hVtx->GetNbinsX(); iVtx++) {
    Float_t nEvents      = hVtx->GetBinContent(iVtx);
    Float_t nEventsError = hVtx->GetBinError(iVtx);

    if (nEvents==0) continue;

    for (Int_t iEta=0; iEta<=hEtaVsVtx->GetNbinsY(); iEta++) {
      Float_t value = hEtaVsVtx->GetBinContent(iVtx, iEta) / nEvents;
      if (value==0) continue;
      Float_t error = hEtaVsVtx->GetBinError(iVtx, iEta)/nEvents;
      error = TMath::Sqrt(TMath::Power(hEtaVsVtx->GetBinError(iVtx, iEta)/
				       hEtaVsVtx->GetBinContent(iVtx, iEta),2) +
      			  TMath::Power(nEventsError/nEvents,2));
      hEtaVsVtx->SetBinContent(iVtx, iEta, value);
      hEtaVsVtx->SetBinError(iVtx,   iEta, error);
    }

    //debug
    for (Int_t iEta=0; iEta<=hEtaVsVtxCheck->GetNbinsY(); iEta++) {
      Float_t value = hEtaVsVtxCheck->GetBinContent(iVtx, iEta) / nEvents;
      if (value==0) continue;
      Float_t error = hEtaVsVtxCheck->GetBinError(iVtx, iEta)/nEvents;
      error = TMath::Sqrt(TMath::Power(hEtaVsVtxCheck->GetBinError(iVtx, iEta)/
				       hEtaVsVtxCheck->GetBinContent(iVtx, iEta),2) +
      			  TMath::Power(nEventsError/nEvents,2));
      hEtaVsVtxCheck->SetBinContent(iVtx, iEta, value);
      hEtaVsVtxCheck->SetBinError(iVtx,   iEta, error);
    }
  }

  // then take the wieghted average for each eta
  // is this the right way to do it???
  for (Int_t iEta=0; iEta<=hEtaVsVtx->GetNbinsY(); iEta++) {
    Float_t sum           = 0;
    Float_t sumError2     = 0;
    Int_t   nMeasurements = 0;    

    Float_t sumXw = 0;
    Float_t sumW  = 0;
    
    // do we have several histograms for different vertex positions?
    Int_t vertexBinWidth = hVtx->GetNbinsX() / (kVertexBinning-1);
    for (Int_t vertexPos=0; vertexPos<kVertexBinning; ++vertexPos)
    {
      Int_t vertexBinBegin = 0;
      Int_t vertexBinEnd = hVtx->GetNbinsX();

      // the first histogram is always for the whole vertex range
      if (vertexPos > 0)
      {
        vertexBinBegin = vertexBinWidth * (vertexPos-1);
        vertexBinEnd = vertexBinBegin + vertexBinWidth;
      }

      for (Int_t iVtx=vertexBinBegin; iVtx<=vertexBinEnd; iVtx++) {
        if (hVtx->GetBinContent(iVtx)==0)             continue;
        if (hEtaVsVtxCheck->GetBinContent(iVtx, iEta)==0) continue;

        Float_t w = 1/TMath::Power(hEtaVsVtx->GetBinError(iVtx, iEta),2);
        sumXw = sumXw + hEtaVsVtxCheck->GetBinContent(iVtx, iEta)*w;
        sumW  = sumW + w;

        sum = sum + hEtaVsVtxCheck->GetBinContent(iVtx, iEta);
        sumError2 = sumError2 + TMath::Power(hEtaVsVtxCheck->GetBinError(iVtx, iEta),2);      
        nMeasurements++;
      }
      Float_t dndeta = 0;
      Float_t error  = 0;

      if (nMeasurements!=0) {
        dndeta = sum/Float_t(nMeasurements);
        error  = TMath::Sqrt(sumError2)/Float_t(nMeasurements);

        dndeta = sumXw/sumW;
        error  = 1/TMath::Sqrt(sumW);

        dndeta = dndeta/hdNdEta[vertexPos]->GetBinWidth(iEta);
        error  = error/hdNdEta[vertexPos]->GetBinWidth(iEta);

        hdNdEta[vertexPos]->SetBinContent(iEta, dndeta);
        hdNdEta[vertexPos]->SetBinError(iEta, error);
      }
    }
  }
}

//____________________________________________________________________
void
dNdEtaAnalysis::SaveHistograms() {

  gDirectory->mkdir(GetName());
  gDirectory->cd(GetName());
  
  hEtaVsVtx  ->Write();
  hEtaVsVtxUncorrected->Write();
  hVtx       ->Write();
  for (Int_t i=0; i<kVertexBinning; ++i)
    hdNdEta[i]    ->Write();

  gDirectory->cd("../");
}

//____________________________________________________________________
void dNdEtaAnalysis::DrawHistograms()
{
  TCanvas* canvas = new TCanvas("dNdEtaAnalysis", "dNdEtaAnalysis", 1200, 800);
  canvas->Divide(3, 2);

  canvas->cd(1);
  if (hEtaVsVtx)
    hEtaVsVtx->Draw("COLZ");

  canvas->cd(2);
  if (hEtaVsVtxCheck)
    hEtaVsVtxCheck->Draw("COLZ");

  canvas->cd(3);
  if (hEtaVsVtxUncorrected)
    hEtaVsVtxUncorrected->Draw("COLZ");

  canvas->cd(4);
  TH2F* clone = (TH2F*) hEtaVsVtxCheck->Clone("clone");
  clone->Divide(hEtaVsVtx);
  clone->Draw("COLZ");

  canvas->cd(5);
  if (hVtx)
    hVtx->Draw();

  canvas->cd(6);
  if (hdNdEta[0])
    hdNdEta[0]->Draw();

    // histograms for different vertices?
  if (kVertexBinning > 0)
  {
      // doesnt work, but i dont get it, giving up...
    /*TCanvas* canvas2 =*/ new TCanvas("dNdEtaAnalysisVtx", "dNdEtaAnalysisVtx", 450, 450);
    //Int_t yPads = (Int_t) TMath::Ceil(((Double_t) kVertexBinning - 1) / 2);
    //printf("%d\n", yPads);
    //canvas2->Divide(2, yPads);

    TLegend* legend = new TLegend(0.7, 0.7, 0.9, 0.9);

    for (Int_t i=1; i<kVertexBinning; ++i)
    {
      //canvas2->cd(i-1);
      //printf("%d\n", i);
      if (hdNdEta[i])
      {
        hdNdEta[i]->SetLineColor(i);
        hdNdEta[i]->Draw((i == 1) ? "" : "SAME");
        legend->AddEntry(hdNdEta[i], Form("Vtx Bin %d", i-1));
      }
    }

    legend->Draw();
  }
}

Long64_t dNdEtaAnalysis::Merge(TCollection* list)
{
  // Merges a list of dNdEtaAnalysis objects with this one.
  // This is needed for PROOF.
  // Returns the number of merged objects (including this)

  if (!list)
    return 0;

  if (list->IsEmpty())
    return 1;

  TIterator* iter = list->MakeIterator();
  TObject* obj;

  // sub collections
  const Int_t nCollections = kVertexBinning + 3;
  TList* collections[nCollections];
  for (Int_t i=0; i<nCollections; ++i)
    collections[i] = new TList;

  Int_t count = 0;
  while ((obj = iter->Next()))
  {
    dNdEtaAnalysis* entry = dynamic_cast<dNdEtaAnalysis*> (obj);
    if (entry == 0)
      continue;

    collections[0]->Add(entry->hEtaVsVtx);
    collections[1]->Add(entry->hEtaVsVtxUncorrected);
    collections[2]->Add(entry->hVtx);

    for (Int_t i=0; i<kVertexBinning; ++i)
      collections[3+i]->Add(entry->hdNdEta[i]);

    ++count;
  }

  hEtaVsVtx->Merge(collections[0]);
  hEtaVsVtxUncorrected->Merge(collections[1]);
  hVtx->Merge(collections[2]);
  for (Int_t i=0; i<kVertexBinning; ++i)
    hdNdEta[i]->Merge(collections[3+i]);

  for (Int_t i=0; i<nCollections; ++i)
    delete collections[i];

  return count+1;
}
Commit	Line	Data
dc740de4	1	/* $Id$ */
dc740de4	2
75ec0f41	3	#include "dNdEtaAnalysis.h"
75ec0f41	4
ceb5d1b5	5	#include <TFile.h>
	6	#include <TH2F.h>
	7	#include <TH1D.h>
	8	#include <TMath.h>
	9	#include <TCanvas.h>
7029240a	10	#include <TCollection.h>
	11	#include <TIterator.h>
	12	#include <TList.h>
fcf2fb36	13	#include <TLegend.h>
	14
	15	#include "dNdEtaCorrection.h"
ceb5d1b5	16
75ec0f41	17	//____________________________________________________________________
b7f4a1fd	18	ClassImp(dNdEtaAnalysis)
75ec0f41	19
75ec0f41	20	//____________________________________________________________________
7029240a	21	dNdEtaAnalysis::dNdEtaAnalysis(Char_t* name, Char_t* title) :
	22	TNamed(name, title)
	23	{
	24	hEtaVsVtx = new TH2F(Form("%s_eta_vs_vtx", name),"",80,-20,20,120,-6,6);
75ec0f41	25	hEtaVsVtx->SetXTitle("vtx z [cm]");
75ec0f41	26	hEtaVsVtx->SetYTitle("#eta");
4dd2ad81	27
7029240a	28	hEtaVsVtxUncorrected = dynamic_cast<TH2F*> (hEtaVsVtx->Clone(Form("%s_eta_vs_vtx_uncorrected", name)));
fcf2fb36	29	hEtaVsVtxCheck = dynamic_cast<TH2F*> (hEtaVsVtx->Clone(Form("%s_eta_vs_vtx_check", name)));
7029240a	30	hVtx = hEtaVsVtx->ProjectionX(Form("%s_vtx", name));
	31	for (Int_t i=0; i<kVertexBinning; ++i)
	32	{
	33	hdNdEta[i] = hEtaVsVtx->ProjectionY(Form("%s_dNdEta_%d", name, i));
	34	hdNdEta[i]->SetYTitle("dN/d#eta");
	35	}
75ec0f41	36
	37	hEtaVsVtx->Sumw2();
	38	hVtx->Sumw2();
75ec0f41	39	}
	40
	41	//____________________________________________________________________
	42	void
fcf2fb36	43	dNdEtaAnalysis::FillTrack(Float_t vtx, Float_t eta, Float_t c) {
ceb5d1b5	44	hEtaVsVtxUncorrected->Fill(vtx,eta);
fcf2fb36	45	hEtaVsVtxCheck->Fill(vtx, eta, c);
75ec0f41	46	}
	47
	48	//____________________________________________________________________
	49	void
	50	dNdEtaAnalysis::FillEvent(Float_t vtx) {
	51	hVtx->Fill(vtx);
	52	}
	53
	54	//____________________________________________________________________
fcf2fb36	55	void dNdEtaAnalysis::Finish(dNdEtaCorrection* correction)
	56	{
	57	// correct with correction values if available
	58	// TODO what do we do with the error?
	59	if (!correction)
	60	printf("INFO: No correction applied\n");
	61
	62	// this can be replaced by TH2F::Divide if we agree that the binning will be always the same
	63	for (Int_t iVtx=0; iVtx<=hEtaVsVtxUncorrected->GetNbinsX(); iVtx++)
	64	{
	65	for (Int_t iEta=0; iEta<=hEtaVsVtxUncorrected->GetNbinsY(); iEta++)
	66	{
	67	Float_t correctionValue = 1;
	68	if (correction)
	69	correctionValue = correction->GetCorrection(hEtaVsVtxUncorrected->GetXaxis()->GetBinCenter(iVtx), hEtaVsVtxUncorrected->GetYaxis()->GetBinCenter(iEta));
	70
	71	Float_t value = hEtaVsVtxUncorrected->GetBinContent(iVtx, iEta);
	72	Float_t error = hEtaVsVtxUncorrected->GetBinError(iVtx, iEta);
	73
	74	Float_t correctedValue = value * correctionValue;
	75	Float_t correctedError = error * correctionValue;
	76
	77	if (correctedValue != 0)
	78	{
	79	hEtaVsVtx->SetBinContent(iVtx, iEta, correctedValue);
	80	hEtaVsVtx->SetBinError(iVtx, iEta, correctedError);
	81	}
	82	}
	83	}
	84
	85	// normalize with n events (per vtx)
	86	for (Int_t iVtx=0; iVtx<=hVtx->GetNbinsX(); iVtx++) {
	87	Float_t nEvents = hVtx->GetBinContent(iVtx);
	88	Float_t nEventsError = hVtx->GetBinError(iVtx);
75ec0f41	89
75ec0f41	90	if (nEvents==0) continue;
fcf2fb36	91
	92	for (Int_t iEta=0; iEta<=hEtaVsVtx->GetNbinsY(); iEta++) {
	93	Float_t value = hEtaVsVtx->GetBinContent(iVtx, iEta) / nEvents;
	94	if (value==0) continue;
	95	Float_t error = hEtaVsVtx->GetBinError(iVtx, iEta)/nEvents;
	96	error = TMath::Sqrt(TMath::Power(hEtaVsVtx->GetBinError(iVtx, iEta)/
	97	hEtaVsVtx->GetBinContent(iVtx, iEta),2) +
	98	TMath::Power(nEventsError/nEvents,2));
	99	hEtaVsVtx->SetBinContent(iVtx, iEta, value);
	100	hEtaVsVtx->SetBinError(iVtx, iEta, error);
	101	}
	102
	103	//debug
	104	for (Int_t iEta=0; iEta<=hEtaVsVtxCheck->GetNbinsY(); iEta++) {
	105	Float_t value = hEtaVsVtxCheck->GetBinContent(iVtx, iEta) / nEvents;
75ec0f41	106	if (value==0) continue;
fcf2fb36	107	Float_t error = hEtaVsVtxCheck->GetBinError(iVtx, iEta)/nEvents;
	108	error = TMath::Sqrt(TMath::Power(hEtaVsVtxCheck->GetBinError(iVtx, iEta)/
	109	hEtaVsVtxCheck->GetBinContent(iVtx, iEta),2) +
75ec0f41	110	TMath::Power(nEventsError/nEvents,2));
fcf2fb36	111	hEtaVsVtxCheck->SetBinContent(iVtx, iEta, value);
fcf2fb36	112	hEtaVsVtxCheck->SetBinError(iVtx, iEta, error);
75ec0f41	113	}
	114	}
	115
	116	// then take the wieghted average for each eta
	117	// is this the right way to do it???
fcf2fb36	118	for (Int_t iEta=0; iEta<=hEtaVsVtx->GetNbinsY(); iEta++) {
75ec0f41	119	Float_t sum = 0;
	120	Float_t sumError2 = 0;
	121	Int_t nMeasurements = 0;
	122
fcf2fb36	123	Float_t sumXw = 0;
fcf2fb36	124	Float_t sumW = 0;
75ec0f41	125
7029240a	126	// do we have several histograms for different vertex positions?
fcf2fb36	127	Int_t vertexBinWidth = hVtx->GetNbinsX() / (kVertexBinning-1);
7029240a	128	for (Int_t vertexPos=0; vertexPos<kVertexBinning; ++vertexPos)
7029240a	129	{
fcf2fb36	130	Int_t vertexBinBegin = 0;
	131	Int_t vertexBinEnd = hVtx->GetNbinsX();
	132
	133	// the first histogram is always for the whole vertex range
	134	if (vertexPos > 0)
	135	{
	136	vertexBinBegin = vertexBinWidth * (vertexPos-1);
	137	vertexBinEnd = vertexBinBegin + vertexBinWidth;
	138	}
7029240a	139
fcf2fb36	140	for (Int_t iVtx=vertexBinBegin; iVtx<=vertexBinEnd; iVtx++) {
fcf2fb36	141	if (hVtx->GetBinContent(iVtx)==0) continue;
a8d3b360	142	if (hEtaVsVtxCheck->GetBinContent(iVtx, iEta)==0) continue;
7029240a	143
fcf2fb36	144	Float_t w = 1/TMath::Power(hEtaVsVtx->GetBinError(iVtx, iEta),2);
a8d3b360	145	sumXw = sumXw + hEtaVsVtxCheck->GetBinContent(iVtx, iEta)*w;
fcf2fb36	146	sumW = sumW + w;
7029240a	147
a8d3b360	148	sum = sum + hEtaVsVtxCheck->GetBinContent(iVtx, iEta);
a8d3b360	149	sumError2 = sumError2 + TMath::Power(hEtaVsVtxCheck->GetBinError(iVtx, iEta),2);
7029240a	150	nMeasurements++;
	151	}
	152	Float_t dndeta = 0;
	153	Float_t error = 0;
	154
	155	if (nMeasurements!=0) {
	156	dndeta = sum/Float_t(nMeasurements);
	157	error = TMath::Sqrt(sumError2)/Float_t(nMeasurements);
	158
fcf2fb36	159	dndeta = sumXw/sumW;
fcf2fb36	160	error = 1/TMath::Sqrt(sumW);
7029240a	161
fcf2fb36	162	dndeta = dndeta/hdNdEta[vertexPos]->GetBinWidth(iEta);
fcf2fb36	163	error = error/hdNdEta[vertexPos]->GetBinWidth(iEta);
7029240a	164
fcf2fb36	165	hdNdEta[vertexPos]->SetBinContent(iEta, dndeta);
fcf2fb36	166	hdNdEta[vertexPos]->SetBinError(iEta, error);
7029240a	167	}
75ec0f41	168	}
75ec0f41	169	}
	170	}
	171
75ec0f41	172	//____________________________________________________________________
	173	void
	174	dNdEtaAnalysis::SaveHistograms() {
	175
7029240a	176	gDirectory->mkdir(GetName());
7029240a	177	gDirectory->cd(GetName());
75ec0f41	178
75ec0f41	179	hEtaVsVtx ->Write();
fcf2fb36	180	hEtaVsVtxUncorrected->Write();
75ec0f41	181	hVtx ->Write();
7029240a	182	for (Int_t i=0; i<kVertexBinning; ++i)
7029240a	183	hdNdEta[i] ->Write();
75ec0f41	184
	185	gDirectory->cd("../");
	186	}
	187
ceb5d1b5	188	//____________________________________________________________________
	189	void dNdEtaAnalysis::DrawHistograms()
	190	{
a8d3b360	191	TCanvas* canvas = new TCanvas("dNdEtaAnalysis", "dNdEtaAnalysis", 1200, 800);
a8d3b360	192	canvas->Divide(3, 2);
ceb5d1b5	193
	194	canvas->cd(1);
	195	if (hEtaVsVtx)
	196	hEtaVsVtx->Draw("COLZ");
	197
	198	canvas->cd(2);
fcf2fb36	199	if (hEtaVsVtxCheck)
	200	hEtaVsVtxCheck->Draw("COLZ");
	201
	202	canvas->cd(3);
ceb5d1b5	203	if (hEtaVsVtxUncorrected)
	204	hEtaVsVtxUncorrected->Draw("COLZ");
	205
a8d3b360	206	canvas->cd(4);
	207	TH2F* clone = (TH2F*) hEtaVsVtxCheck->Clone("clone");
	208	clone->Divide(hEtaVsVtx);
	209	clone->Draw("COLZ");
	210
	211	canvas->cd(5);
ceb5d1b5	212	if (hVtx)
a8d3b360	213	hVtx->Draw();
ceb5d1b5	214
a8d3b360	215	canvas->cd(6);
7029240a	216	if (hdNdEta[0])
7029240a	217	hdNdEta[0]->Draw();
fcf2fb36	218
	219	// histograms for different vertices?
	220	if (kVertexBinning > 0)
	221	{
	222	// doesnt work, but i dont get it, giving up...
	223	/TCanvas canvas2 =*/ new TCanvas("dNdEtaAnalysisVtx", "dNdEtaAnalysisVtx", 450, 450);
	224	//Int_t yPads = (Int_t) TMath::Ceil(((Double_t) kVertexBinning - 1) / 2);
	225	//printf("%d\n", yPads);
	226	//canvas2->Divide(2, yPads);
	227
	228	TLegend* legend = new TLegend(0.7, 0.7, 0.9, 0.9);
	229
	230	for (Int_t i=1; i<kVertexBinning; ++i)
	231	{
	232	//canvas2->cd(i-1);
	233	//printf("%d\n", i);
	234	if (hdNdEta[i])
	235	{
	236	hdNdEta[i]->SetLineColor(i);
	237	hdNdEta[i]->Draw((i == 1) ? "" : "SAME");
	238	legend->AddEntry(hdNdEta[i], Form("Vtx Bin %d", i-1));
	239	}
	240	}
	241
	242	legend->Draw();
	243	}
7029240a	244	}
	245
	246	Long64_t dNdEtaAnalysis::Merge(TCollection* list)
	247	{
	248	// Merges a list of dNdEtaAnalysis objects with this one.
	249	// This is needed for PROOF.
	250	// Returns the number of merged objects (including this)
	251
	252	if (!list)
	253	return 0;
	254
	255	if (list->IsEmpty())
	256	return 1;
	257
	258	TIterator* iter = list->MakeIterator();
	259	TObject* obj;
	260
	261	// sub collections
	262	const Int_t nCollections = kVertexBinning + 3;
	263	TList* collections[nCollections];
	264	for (Int_t i=0; i<nCollections; ++i)
	265	collections[i] = new TList;
	266
	267	Int_t count = 0;
	268	while ((obj = iter->Next()))
	269	{
	270	dNdEtaAnalysis* entry = dynamic_cast<dNdEtaAnalysis*> (obj);
	271	if (entry == 0)
	272	continue;
	273
	274	collections[0]->Add(entry->hEtaVsVtx);
	275	collections[1]->Add(entry->hEtaVsVtxUncorrected);
	276	collections[2]->Add(entry->hVtx);
	277
	278	for (Int_t i=0; i<kVertexBinning; ++i)
	279	collections[3+i]->Add(entry->hdNdEta[i]);
	280
	281	++count;
	282	}
	283
	284	hEtaVsVtx->Merge(collections[0]);
	285	hEtaVsVtxUncorrected->Merge(collections[1]);
	286	hVtx->Merge(collections[2]);
	287	for (Int_t i=0; i<kVertexBinning; ++i)
	288	hdNdEta[i]->Merge(collections[3+i]);
	289
	290	for (Int_t i=0; i<nCollections; ++i)
	291	delete collections[i];
	292
	293	return count+1;
ceb5d1b5	294	}