1 #include "dNdEtaAnalysis.h"
9 //____________________________________________________________________
10 ClassImp(dNdEtaAnalysis)
12 //____________________________________________________________________
13 dNdEtaAnalysis::dNdEtaAnalysis(Char_t* name) {
15 fName = TString(name);
17 hEtaVsVtx = new TH2F("eta_vs_vtx","",80,-20,20,120,-6,6);
18 hEtaVsVtx->SetXTitle("vtx z [cm]");
19 hEtaVsVtx->SetYTitle("#eta");
21 hEtaVsVtxUncorrected = dynamic_cast<TH2F*> (hEtaVsVtx->Clone("eta_vs_vtx_uncorrected"));
22 hVtx = hEtaVsVtx->ProjectionX("vtx");
23 hdNdEta = hEtaVsVtx->ProjectionY("dNdEta");
25 hdNdEta->SetYTitle("dN/d#eta");
31 //____________________________________________________________________
33 dNdEtaAnalysis::FillTrack(Float_t vtx, Float_t eta, Float_t weight) {
34 hEtaVsVtx->Fill(vtx, eta, weight);
35 hEtaVsVtxUncorrected->Fill(vtx,eta);
38 //____________________________________________________________________
40 dNdEtaAnalysis::FillEvent(Float_t vtx) {
44 //____________________________________________________________________
46 dNdEtaAnalysis::Finish() {
48 // first normalize with n events (per vtx)
49 for (Int_t i_vtx=0; i_vtx<=hVtx->GetNbinsX(); i_vtx++) {
50 Float_t nEvents = hVtx->GetBinContent(i_vtx);
51 Float_t nEventsError = hVtx->GetBinError(i_vtx);
53 if (nEvents==0) continue;
55 for (Int_t i_eta=0; i_eta<=hEtaVsVtx->GetNbinsY(); i_eta++) {
56 Float_t value = hEtaVsVtx->GetBinContent(i_vtx, i_eta)/nEvents;
57 if (value==0) continue;
58 Float_t error = hEtaVsVtx->GetBinError(i_vtx, i_eta)/nEvents;
59 error = TMath::Sqrt(TMath::Power(hEtaVsVtx->GetBinError(i_vtx, i_eta)/
60 hEtaVsVtx->GetBinContent(i_vtx, i_eta),2) +
61 TMath::Power(nEventsError/nEvents,2));
62 hEtaVsVtx->SetBinContent(i_vtx, i_eta, value);
63 hEtaVsVtx->SetBinError(i_vtx, i_eta, error);
67 // then take the wieghted average for each eta
68 // is this the right way to do it???
69 for (Int_t i_eta=0; i_eta<=hEtaVsVtx->GetNbinsY(); i_eta++) {
71 Float_t sumError2 = 0;
72 Int_t nMeasurements = 0;
77 for (Int_t i_vtx=0; i_vtx<=hVtx->GetNbinsX(); i_vtx++) {
78 if (hVtx->GetBinContent(i_vtx)==0) continue;
79 if (hEtaVsVtx->GetBinContent(i_vtx, i_eta)==0) continue;
81 Float_t w = 1/TMath::Power(hEtaVsVtx->GetBinError(i_vtx, i_eta),2);
82 sum_xw = sum_xw + hEtaVsVtx->GetBinContent(i_vtx, i_eta)*w;
85 sum = sum + hEtaVsVtx->GetBinContent(i_vtx, i_eta);
86 sumError2 = sumError2 + TMath::Power(hEtaVsVtx->GetBinError(i_vtx, i_eta),2);
92 if (nMeasurements!=0) {
93 dndeta = sum/Float_t(nMeasurements);
94 error = TMath::Sqrt(sumError2)/Float_t(nMeasurements);
96 dndeta = sum_xw/sum_w;
97 error = 1/TMath::Sqrt(sum_w);
99 dndeta = dndeta/hdNdEta->GetBinWidth(i_eta);
100 error = error/hdNdEta->GetBinWidth(i_eta);
102 hdNdEta->SetBinContent(i_eta, dndeta);
103 hdNdEta->SetBinError(i_eta, error);
111 //____________________________________________________________________
113 dNdEtaAnalysis::SaveHistograms() {
115 gDirectory->mkdir(fName.Data());
116 gDirectory->cd(fName.Data());
122 gDirectory->cd("../");
125 //____________________________________________________________________
126 void dNdEtaAnalysis::DrawHistograms()
128 TCanvas* canvas = new TCanvas("dNdEtaAnalysis", "dNdEtaAnalysis", 800, 800);
129 canvas->Divide(2, 2);
133 hEtaVsVtx->Draw("COLZ");
136 if (hEtaVsVtxUncorrected)
137 hEtaVsVtxUncorrected->Draw("COLZ");