1 #ifndef ALIVERTEXERTRACKS_H
2 #define ALIVERTEXERTRACKS_H
3 /* Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
7 //-------------------------------------------------------
8 // Class for vertex determination with tracks
10 // Origin: AliITSVertexerTracks
11 // A.Dainese, Padova, andrea.dainese@pd.infn.it
12 // M.Masera, Torino, massimo.masera@to.infn.it
13 // Moved to STEER and adapted to ESD tracks:
14 // F.Prino, Torino, prino@to.infn.it
15 //-------------------------------------------------------
17 /*****************************************************************************
19 * This class determines the vertex of a set of tracks. *
20 * Different algorithms are implemented, see data member fAlgo. *
22 *****************************************************************************/
24 #include <TObjArray.h>
27 #include "AliESDVertex.h"
28 #include "AliExternalTrackParam.h"
33 class AliVertexerTracks : public TObject {
37 AliVertexerTracks(Double_t fieldkG);
38 virtual ~AliVertexerTracks();
40 AliESDVertex* FindPrimaryVertex(const AliESDEvent *esdEvent);
41 AliESDVertex* FindPrimaryVertex(TObjArray *trkArrayOrig,UShort_t *idOrig);
42 AliESDVertex* VertexForSelectedTracks(TObjArray *trkArray,UShort_t *id,
43 Bool_t optUseFitter=kTRUE,
44 Bool_t optPropagate=kTRUE);
45 AliESDVertex* VertexForSelectedESDTracks(TObjArray *trkArray,
46 Bool_t optUseFitter=kTRUE,
47 Bool_t optPropagate=kTRUE);
48 AliESDVertex* RemoveTracksFromVertex(AliESDVertex *inVtx,
49 TObjArray *trkArray,UShort_t *id,
51 void SetITSMode(Double_t dcacut=0.1,
52 Double_t dcacutIter0=0.1,
57 Double_t mindetfitter=100.,
58 Double_t maxtgl=1000.,
61 void SetTPCMode(Double_t dcacut=0.1,
62 Double_t dcacutIter0=1.0,
67 Double_t mindetfitter=0.1,
71 void SetCuts(Double_t *cuts);
72 void SetConstraintOff() { fConstraint=kFALSE; return; }
73 void SetConstraintOn() { fConstraint=kTRUE; return; }
74 void SetDebug(Int_t optdebug=0) { fDebug=optdebug; return; }
75 void SetDCAcut(Double_t maxdca) { fDCAcut=maxdca; return; }
76 void SetDCAcutIter0(Double_t maxdca) { fDCAcutIter0=maxdca; return; }
77 void SetFinderAlgorithm(Int_t opt=1) { fAlgo=opt; return; }
78 void SetITSrefitRequired() { fITSrefit=kTRUE; return; }
79 void SetITSrefitNotRequired() { fITSrefit=kFALSE; return; }
80 void SetFiducialRZ(Double_t r=3,Double_t z=30) { fFiducialR=r; fFiducialZ=z; return; }
81 void SetMaxd0z0(Double_t maxd0z0=0.5) { fMaxd0z0=maxd0z0; return; }
82 void SetMinClusters(Int_t n=5) { fMinClusters=n; return; }
83 void SetMinTracks(Int_t n=1) { fMinTracks=n; return; }
84 void SetNSigmad0(Double_t n=3) { fNSigma=n; return; }
85 Double_t GetNSigmad0() const { return fNSigma; }
86 void SetMinDetFitter(Double_t mindet=100.) { fMinDetFitter=mindet; return; }
87 void SetMaxTgl(Double_t maxtgl=1.) { fMaxTgl=maxtgl; return; }
88 void SetOnlyFitter() { if(!fConstraint) AliFatal("Set constraint first!");
89 fOnlyFitter=kTRUE; return; }
90 void SetSkipTracks(Int_t n,Int_t *skipped);
91 void SetVtxStart(Double_t x=0,Double_t y=0,Double_t z=0)
92 { fNominalPos[0]=x; fNominalPos[1]=y; fNominalPos[2]=z; return; }
93 void SetVtxStartSigma(Double_t sx=3.,Double_t sy=3.,Double_t sz=15.)
94 { fNominalCov[0]=sx*sx; fNominalCov[2]=sy*sy; fNominalCov[5]=sz*sz;
95 fNominalCov[1]=0.; fNominalCov[3]=0.; fNominalCov[4]=0.; return; }
96 void SetVtxStart(AliESDVertex *vtx);
97 static Double_t GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0);
98 static Double_t GetDeterminant3X3(Double_t matr[][3]);
99 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d);
100 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d);
101 static AliESDVertex TrackletVertexFinder(TClonesArray *lines, Int_t optUseWeights=0);
102 void SetFieldkG(Double_t field=-999.) { fFieldkG=field; return; }
103 Double_t GetFieldkG() const {
104 if(fFieldkG<-99.) AliFatal("Field value not set");
106 void SetNSigmaForUi00(Double_t n=1.5) { fnSigmaForUi00=n; return; }
107 Double_t GetNSigmaForUi00() const { return fnSigmaForUi00; }
110 void HelixVertexFinder();
111 void OneTrackVertFinder();
112 Int_t PrepareTracks(TObjArray &trkArrayOrig,UShort_t *idOrig,
114 Bool_t PropagateTrackTo(AliExternalTrackParam *track,
116 Bool_t TrackToPoint(AliExternalTrackParam *t,
117 TMatrixD &ri,TMatrixD &wWi,
118 Bool_t uUi3by3=kFALSE) const;
119 void VertexFinder(Int_t optUseWeights=0);
121 void StrLinVertexFinderMinDist(Int_t optUseWeights=0);
124 AliESDVertex fVert; // vertex after vertex finder
125 AliESDVertex *fCurrentVertex; // ESD vertex after fitter
126 UShort_t fMode; // 0 ITS+TPC; 1 TPC
127 Double_t fFieldkG; // z component of field (kGauss)
128 Double_t fNominalPos[3]; // initial knowledge on vertex position
129 Double_t fNominalCov[6]; // initial knowledge on vertex position
130 TObjArray fTrkArraySel; // array with tracks to be processed
131 UShort_t *fIdSel; // IDs of the tracks (AliESDtrack::GetID())
132 Int_t *fTrksToSkip; // track IDs to be skipped for find and fit
133 Int_t fNTrksToSkip; // number of tracks to be skipped
134 Bool_t fConstraint; // true when "mean vertex" was set in
135 // fNominal ... and must be used in the fit
136 Bool_t fOnlyFitter; // primary with one fitter shot only
137 // (use only with beam constraint)
138 Int_t fMinTracks; // minimum number of tracks
139 Int_t fMinClusters; // minimum number of ITS or TPC clusters per track
140 Double_t fDCAcut; // maximum DCA between 2 tracks used for vertex
141 Double_t fDCAcutIter0; // maximum DCA between 2 tracks used for vertex
142 Double_t fNSigma; // number of sigmas for d0 cut in PrepareTracks()
143 Double_t fMaxd0z0; // value for sqrt(d0d0+z0z0) cut
144 // in PrepareTracks(1) if fConstraint=kFALSE
145 Double_t fMinDetFitter; // minimum determinant to try to invertex matrix
146 Double_t fMaxTgl; // maximum tgl of tracks
147 Bool_t fITSrefit; // if kTRUE (default), use only kITSrefit tracks
148 // if kFALSE, use all tracks (also TPC only)
149 Double_t fFiducialR; // radius of fiducial cylinder for tracks
150 Double_t fFiducialZ; // length of fiducial cylinder for tracks
151 Double_t fnSigmaForUi00; // n. sigmas from finder in TrackToPoint
152 Int_t fDebug; //! debug flag - verbose printing if >0
153 Int_t fAlgo; // option for vertex finding algorythm
154 // fAlgo=1 (default) finds minimum-distance point among all selected tracks
155 // approximated as straight lines
156 // and uses errors on track parameters as weights
157 // fAlgo=2 finds minimum-distance point among all the selected tracks
158 // approximated as straight lines
159 // fAlgo=3 finds the average point among DCA points of all pairs of tracks
160 // treated as helices
161 // fAlgo=4 finds the average point among DCA points of all pairs of tracks
162 // approximated as straight lines
163 // and uses errors on track parameters as weights
164 // fAlgo=5 finds the average point among DCA points of all pairs of tracks
165 // approximated as straight lines
169 AliVertexerTracks(const AliVertexerTracks & source);
170 AliVertexerTracks & operator=(const AliVertexerTracks & source);
172 ClassDef(AliVertexerTracks,11) // 3D Vertexing with tracks