3 #include "dNdEtaAnalysis.h"
11 //____________________________________________________________________
12 ClassImp(dNdEtaAnalysis)
14 //____________________________________________________________________
15 dNdEtaAnalysis::dNdEtaAnalysis(Char_t* name) {
17 fName = TString(name);
19 hEtaVsVtx = new TH2F("eta_vs_vtx","",80,-20,20,120,-6,6);
20 hEtaVsVtx->SetXTitle("vtx z [cm]");
21 hEtaVsVtx->SetYTitle("#eta");
23 hEtaVsVtxUncorrected = dynamic_cast<TH2F*> (hEtaVsVtx->Clone("eta_vs_vtx_uncorrected"));
24 hVtx = hEtaVsVtx->ProjectionX("vtx");
25 hdNdEta = hEtaVsVtx->ProjectionY("dNdEta");
27 hdNdEta->SetYTitle("dN/d#eta");
33 //____________________________________________________________________
35 dNdEtaAnalysis::FillTrack(Float_t vtx, Float_t eta, Float_t weight) {
36 hEtaVsVtx->Fill(vtx, eta, weight);
37 hEtaVsVtxUncorrected->Fill(vtx,eta);
40 //____________________________________________________________________
42 dNdEtaAnalysis::FillEvent(Float_t vtx) {
46 //____________________________________________________________________
48 dNdEtaAnalysis::Finish() {
50 // first normalize with n events (per vtx)
51 for (Int_t i_vtx=0; i_vtx<=hVtx->GetNbinsX(); i_vtx++) {
52 Float_t nEvents = hVtx->GetBinContent(i_vtx);
53 Float_t nEventsError = hVtx->GetBinError(i_vtx);
55 if (nEvents==0) continue;
57 for (Int_t i_eta=0; i_eta<=hEtaVsVtx->GetNbinsY(); i_eta++) {
58 Float_t value = hEtaVsVtx->GetBinContent(i_vtx, i_eta)/nEvents;
59 if (value==0) continue;
60 Float_t error = hEtaVsVtx->GetBinError(i_vtx, i_eta)/nEvents;
61 error = TMath::Sqrt(TMath::Power(hEtaVsVtx->GetBinError(i_vtx, i_eta)/
62 hEtaVsVtx->GetBinContent(i_vtx, i_eta),2) +
63 TMath::Power(nEventsError/nEvents,2));
64 hEtaVsVtx->SetBinContent(i_vtx, i_eta, value);
65 hEtaVsVtx->SetBinError(i_vtx, i_eta, error);
69 // then take the wieghted average for each eta
70 // is this the right way to do it???
71 for (Int_t i_eta=0; i_eta<=hEtaVsVtx->GetNbinsY(); i_eta++) {
73 Float_t sumError2 = 0;
74 Int_t nMeasurements = 0;
79 for (Int_t i_vtx=0; i_vtx<=hVtx->GetNbinsX(); i_vtx++) {
80 if (hVtx->GetBinContent(i_vtx)==0) continue;
81 if (hEtaVsVtx->GetBinContent(i_vtx, i_eta)==0) continue;
83 Float_t w = 1/TMath::Power(hEtaVsVtx->GetBinError(i_vtx, i_eta),2);
84 sum_xw = sum_xw + hEtaVsVtx->GetBinContent(i_vtx, i_eta)*w;
87 sum = sum + hEtaVsVtx->GetBinContent(i_vtx, i_eta);
88 sumError2 = sumError2 + TMath::Power(hEtaVsVtx->GetBinError(i_vtx, i_eta),2);
94 if (nMeasurements!=0) {
95 dndeta = sum/Float_t(nMeasurements);
96 error = TMath::Sqrt(sumError2)/Float_t(nMeasurements);
98 dndeta = sum_xw/sum_w;
99 error = 1/TMath::Sqrt(sum_w);
101 dndeta = dndeta/hdNdEta->GetBinWidth(i_eta);
102 error = error/hdNdEta->GetBinWidth(i_eta);
104 hdNdEta->SetBinContent(i_eta, dndeta);
105 hdNdEta->SetBinError(i_eta, error);
113 //____________________________________________________________________
115 dNdEtaAnalysis::SaveHistograms() {
117 gDirectory->mkdir(fName.Data());
118 gDirectory->cd(fName.Data());
124 gDirectory->cd("../");
127 //____________________________________________________________________
128 void dNdEtaAnalysis::DrawHistograms()
130 TCanvas* canvas = new TCanvas("dNdEtaAnalysis", "dNdEtaAnalysis", 800, 800);
131 canvas->Divide(2, 2);
135 hEtaVsVtx->Draw("COLZ");
138 if (hEtaVsVtxUncorrected)
139 hEtaVsVtxUncorrected->Draw("COLZ");