+/***********************************************************************************************************
+ * *
+ * Helper class for TRD PID efficiency calculation Calculation of the hadron efficiency depenedent on *
+ * momentum and of the errors implemented in function CalculatePionEff. The pion efficiency is based on a *
+ * predefined electron efficiency. The default is 90%. To change the, one has to call the function *
+ * SetElectronEfficiency. *
+ * Other Helper functions decide based on 90% electron efficiency whether a certain track is accepted *
+ * as Electron Track. The reference data is stored in the TRD OCDB. *
+ * *
+ ***********************************************************************************************************/
#include "TObject.h"
#include "TObjArray.h"
#include "TMath.h"
ClassImp(AliTRDpidUtil)
-Float_t AliTRDpidUtil::fEleEffi = 0.9;
+Float_t AliTRDpidUtil::fgEleEffi = 0.9;
//________________________________________________________________________
AliTRDpidUtil::AliTRDpidUtil()
//
}
-
-
//________________________________________________________________________
Bool_t AliTRDpidUtil::CalculatePionEffi(TH1* histo1, TH1* histo2)
// Double_t AliTRDpidUtil::GetError()
histo1 -> SetLineColor(kRed);
histo2 -> SetLineColor(kBlue);
- if(!histo1 -> GetEntries() || !histo2 -> GetEntries()){
- AliWarning("Histo with no entries !");
+ if(!histo1->GetEntries() || !histo2 -> GetEntries()){
+ AliError("Probability histos empty !");
+ return kFALSE;
+ }
+ if(histo1->GetNbinsX() != histo2->GetNbinsX()){
+ AliError(Form("Electron probability discretized differently from pions [%d %d] !", histo1->GetNbinsX(), histo2->GetNbinsX()));
return kFALSE;
}
histo1 -> Scale(1./histo1->GetEntries());
histo2 -> Scale(1./histo2->GetEntries());
- Int_t abinE, bbinE, cbinE = -1;
- Double_t aBinSumE, bBinSumE; // content of a single bin
- Bool_t bFirst = 1; // checks if threshold is crossed for the first time
- Double_t SumElecsE[kBins+2], SumPionsE[kBins+2]; // array of the integrated sum in each bin
- memset(SumElecsE, 0, (kBins+2)*sizeof(Double_t));
- memset(SumPionsE, 0, (kBins+2)*sizeof(Double_t));
-
-
- // calculate electron efficiency of each bin
- for (abinE = (histo1 -> GetNbinsX()); abinE >= 0; abinE--){
- aBinSumE = 0;
- aBinSumE = histo1 -> GetBinContent(abinE);
-
- SumElecsE[abinE] = SumElecsE[abinE+1] + aBinSumE;
-
- if((SumElecsE[abinE] >= fEleEffi) && (bFirst == 1)){
- bFirst = 0;
+ // array of the integrated sum in each bin
+ Double_t sumElecE[kBins+2], sumPionsE[kBins+2];
+ memset(sumElecE, 0, (kBins+2)*sizeof(Double_t));
+ memset(sumPionsE, 0, (kBins+2)*sizeof(Double_t));
+
+ Int_t nbinE(histo1->GetNbinsX()),
+ abinE(nbinE),
+ bbinE(nbinE),
+ cbinE(-1);
+ // calculate electron efficiency for each bin
+ // and also integral distribution
+ for(Bool_t bFirst(kTRUE); abinE--;){
+ sumElecE[abinE] = sumElecE[abinE+1] + histo1->GetBinContent(abinE+1);
+ if((sumElecE[abinE] >= fgEleEffi) && bFirst){
cbinE = abinE;
- fCalcEleEffi = (SumElecsE[cbinE]);
+ fCalcEleEffi = sumElecE[cbinE];
+ bFirst = kFALSE;
}
}
-
- fThreshold = histo1 -> GetBinCenter(cbinE);
+ fThreshold = histo1->GetBinCenter(cbinE);
// calculate pion efficiency of each bin
- for (bbinE = (histo2 -> GetNbinsX()); bbinE >= abinE; bbinE--){
- bBinSumE = 0;
- bBinSumE = histo2 -> GetBinContent(bbinE);
-
- SumPionsE[bbinE] = SumPionsE[bbinE+1] + bBinSumE;
- if(bbinE == cbinE){
- fPionEffi = (SumPionsE[cbinE]);
- }
+ // and also integral distribution
+ for (;bbinE--;){
+ sumPionsE[bbinE] = sumPionsE[bbinE+1] + histo2->GetBinContent(bbinE+1);
+ if(bbinE == cbinE) fPionEffi = sumPionsE[cbinE];
}
// pion efficiency vs electron efficiency
- TGraph gEffis(kBins, SumElecsE, SumPionsE);
+ TGraph gEffis(nbinE, sumElecE, sumPionsE);
// use fit function to get derivate of the TGraph for error calculation
- TF1 f1("f1","[0]*x*x+[1]*x+[2]", fEleEffi-.05, fEleEffi+.05);
- gEffis.Fit(&f1, "Q", "", fEleEffi-.05, fEleEffi+.05);
+ TF1 f1("f1","[0]*x*x+[1]*x+[2]", fgEleEffi-.05, fgEleEffi+.05);
+ gEffis.Fit(&f1, "Q", "", fgEleEffi-.05, fgEleEffi+.05);
// return the error of the pion efficiency
if(((1.-fPionEffi) < 0) || ((1.-fCalcEleEffi) < 0)){
- AliWarning(" EleEffi or PioEffi > 1. Error can not be calculated. Please increase statistics or check your simulation!");
+ AliError(" EleEffi or PioEffi > 1. Error can not be calculated. Please increase statistics or check your simulation!");
return kFALSE;
}
- fError = sqrt(((1/histo2 -> GetEntries())*fPionEffi*(1-fPionEffi))+((f1.Derivative(fEleEffi))*(f1.Derivative(fEleEffi))*(1/histo1 -> GetEntries())*fCalcEleEffi*(1-fCalcEleEffi)));
+ fError = sqrt(((1/histo2 -> GetEntries())*fPionEffi*(1-fPionEffi))+((f1.Derivative(fgEleEffi))*(f1.Derivative(fgEleEffi))*(1/histo1 -> GetEntries())*fCalcEleEffi*(1-fCalcEleEffi)));
-// AliInfo(Form("Pion Effi at [%f] : [%f +/- %f], Threshold[%f]", fCalcEleEffi, fPionEffi, fError, fThreshold));
-// AliInfo(Form("Derivative at %4.2f : %f\n", fEleEffi, f1.Derivative(fEleEffi)));
+ AliDebug(2, Form("Pion Effi at [%f] : [%f +/- %f], Threshold[%f]", fCalcEleEffi, fPionEffi, fError, fThreshold));
+ AliDebug(2, Form("Derivative at %4.2f : %f\n", fgEleEffi, f1.Derivative(fgEleEffi)));
return kTRUE;
}
if(method == kESD) method = kNN;
TString histname[2] = {"fHistThreshLQ", "fHistThreshNN"};
AliCDBManager *cdb = AliCDBManager::Instance();
- AliCDBEntry *cdb_thresholds = cdb->Get("TRD/Calib/PIDThresholds");
- TObjArray *histos = dynamic_cast<TObjArray *>(cdb_thresholds->GetObject());
- TH1 * threshold_hist = dynamic_cast<TH1F *>(histos->FindObject(histname[method].Data()));
- Double_t threshold = threshold_hist->GetBinContent(GetMomentumBin(track->P()) + 1);
+ AliCDBEntry *cdbThresholds = cdb->Get("TRD/Calib/PIDThresholds");
+ TObjArray *histos = dynamic_cast<TObjArray *>(cdbThresholds->GetObject());
+ TH1 * thresholdHist = dynamic_cast<TH1F *>(histos->FindObject(histname[method].Data()));
+ Double_t threshold = thresholdHist->GetBinContent(GetMomentumBin(track->P()) + 1);
// Do Decision
Double_t pid_probs[5];
if(method == kESD) method = kNN;
TString histname[2] = {"fHistPionEffLQ", "fHistPionEffNN"};
AliCDBManager *cdb = AliCDBManager::Instance();
- AliCDBEntry *cdb_thresholds = cdb->Get("TRD/Calib/PIDThresholds");
- TObjArray *histos = dynamic_cast<TObjArray *>(cdb_thresholds->GetObject());
- TH1 * threshold_hist = dynamic_cast<TH1F *>(histos->FindObject(histname[method].Data()));
- return threshold_hist->GetBinContent(GetMomentumBin(track->P()) + 1);
+ AliCDBEntry *cdbThresholds = cdb->Get("TRD/Calib/PIDThresholds");
+ TObjArray *histos = dynamic_cast<TObjArray *>(cdbThresholds->GetObject());
+ TH1 * thresholdHist = dynamic_cast<TH1F *>(histos->FindObject(histname[method].Data()));
+ return thresholdHist->GetBinContent(GetMomentumBin(track->P()) + 1);
}
//________________________________________________________________________