+//______________________________________________________________________________
+void AliESDEvent::EstimateMultiplicity(Int_t &tracklets, Int_t &trITSTPC, Int_t &trITSSApure, Double_t eta, Bool_t useDCAFlag,Bool_t useV0Flag) const
+{
+ //
+ // calculates 3 estimators for the multiplicity in the -eta:eta range
+ // tracklets : using SPD tracklets only
+ // trITSTPC : using TPC/ITS + complementary ITS SA tracks + tracklets from clusters not used by tracks
+ // trITSSApure : using ITS standalone tracks + tracklets from clusters not used by tracks
+ // if useDCAFlag is true: account for the ESDtrack flag marking the tracks with large DCA
+ // if useV0Flag is true: account for the ESDtrack flag marking conversion and K0's V0s
+ tracklets = trITSSApure = trITSTPC = 0;
+ int ntr = fSPDMult ? fSPDMult->GetNumberOfTracklets() : 0;
+ //
+ // count tracklets
+ for (int itr=ntr;itr--;) {
+ if (TMath::Abs(fSPDMult->GetEta(itr))>eta) continue;
+ tracklets++;
+ if (fSPDMult->FreeClustersTracklet(itr,0)) trITSTPC++; // not used in ITS/TPC or ITS_SA track
+ if (fSPDMult->FreeClustersTracklet(itr,1)) trITSSApure++; // not used in ITS_SA_Pure track
+ }
+ //
+ // count real tracks
+ ntr = GetNumberOfTracks();
+ for (int itr=ntr;itr--;) {
+ AliESDtrack *t = GetTrack(itr);
+ if (TMath::Abs(t->Eta())>eta) continue;
+ if (!t->IsOn(AliESDtrack::kITSin)) continue;
+ if (useDCAFlag && t->IsOn(AliESDtrack::kMultSec)) continue;
+ if (useV0Flag && t->IsOn(AliESDtrack::kMultInV0)) continue;
+ if (t->IsOn(AliESDtrack::kITSpureSA)) trITSSApure++;
+ else trITSTPC++;
+ }
+ //
+}