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 ESD 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 ESD tracks. *
20 * Different algorithms are implemented, see data member fAlgo. *
22 *****************************************************************************/
24 #include "AliESDVertex.h"
25 #include "AliTracker.h"
28 #include <TObjArray.h>
33 class AliVertexerTracks : public TObject {
37 AliVertexerTracks(Double_t xStart, Double_t yStart);
38 virtual ~AliVertexerTracks();
41 // computes the vertex from the set of tracks in the tree
42 AliVertex* VertexForSelectedTracks(TTree *trkTree);
43 AliVertex* VertexForSelectedTracks(TObjArray *trkArray);
44 AliESDVertex* FindPrimaryVertex(const AliESD *esdEvent);
45 void SetMinTracks(Int_t n=1) { fMinTracks = n; return; }
46 void SetITSNotRequired() { fITSrefit=kFALSE;fITSin=kFALSE; return; }
47 void SetITSrefitNotRequired() { fITSrefit=kFALSE; return; }
48 void SetMinITSClusters(Int_t n=5) { fMinITSClusters = n; return; }
49 void SetSkipTracks(Int_t n,Int_t *skipped);
50 void SetDebug(Int_t optdebug=0) {fDebug=optdebug;}
51 void SetVtxStart(Double_t x=0,Double_t y=0,Double_t z=0)
52 { fNominalPos[0]=x; fNominalPos[1]=y; fNominalPos[2]=z; return; }
53 void SetVtxStartSigma(Double_t sx=3,Double_t sy=3,Double_t sz=6)
54 { fNominalCov[0]=sx*sx; fNominalCov[2]=sy*sy; fNominalCov[5]=sz*sz;
55 fNominalCov[1]=0.; fNominalCov[3]=0.; fNominalCov[4]=0.; return; }
56 void SetVtxStart(AliESDVertex *vtx);
57 void SetDCAcut(Double_t maxdca) { fDCAcut=maxdca; return; }
58 void SetFinderAlgorithm(Int_t opt=1) { fAlgo=opt; return; }
59 void SetNSigmad0(Double_t n=3) { fNSigma=n; return; }
60 Double_t GetNSigmad0() const { return fNSigma; }
61 static Double_t GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0);
62 static Double_t GetDeterminant3X3(Double_t matr[][3]);
63 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d);
64 static void GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d);
67 Double_t GetField() const {
68 if(!AliTracker::GetFieldMap())
69 AliFatal("Field map not set; use AliTracker::SetFieldMap()!");
70 return AliTracker::GetBz(); }
71 Int_t PrepareTracks(TTree &trkTree,Int_t OptImpParCut);
72 void OneTrackVertFinder();
73 void VertexFinder(Int_t optUseWeights=0);
74 void HelixVertexFinder();
75 void StrLinVertexFinderMinDist(Int_t OptUseWeights=0);
76 void VertexFitter(Bool_t useNominaVtx=kFALSE);
77 void TooFewTracks(const AliESD *esdEvent);
80 AliVertex fVert; // vertex after vertex finder
81 AliESDVertex *fCurrentVertex; // ESD vertex after fitter
82 Double_t fNominalPos[3]; // initial knowledge on vertex position
83 Double_t fNominalCov[6]; // initial knowledge on vertex position
84 Int_t fMinTracks; // minimum number of tracks
85 Int_t fMinITSClusters; // minimum number of ITS clusters per track
86 TObjArray fTrkArray; // array with tracks to be processed
87 Int_t *fTrksToSkip; // tracks to be skipped for find and fit
88 Int_t fNTrksToSkip; // number of tracks to be skipped
89 Double_t fDCAcut; // maximum DCA between 2 tracks used for vertex
90 Int_t fAlgo; // option for vertex finding algorythm
91 Double_t fNSigma; // number of sigmas for d0 cut in PrepareTracks()
92 Bool_t fITSin; // if kTRUE (default), use only kITSin tracks
93 // if kFALSE, use all tracks (also TPC only)
94 Bool_t fITSrefit; // if kTRUE (default), use only kITSrefit tracks
95 // if kFALSE, use all tracks (also TPC only)
96 Int_t fDebug; //! debug flag - verbose printing if >0
97 // fAlgo=1 (default) finds minimum-distance point among all selected tracks
98 // approximated as straight lines
99 // and uses errors on track parameters as weights
100 // fAlgo=2 finds minimum-distance point among all the selected tracks
101 // approximated as straight lines
102 // fAlgo=3 finds the average point among DCA points of all pairs of tracks
103 // treated as helices
104 // fAlgo=4 finds the average point among DCA points of all pairs of tracks
105 // approximated as straight lines
106 // and uses errors on track parameters as weights
107 // fAlgo=5 finds the average point among DCA points of all pairs of tracks
108 // approximated as straight lines
111 AliVertexerTracks(const AliVertexerTracks & source);
112 AliVertexerTracks & operator=(const AliVertexerTracks & source);
114 ClassDef(AliVertexerTracks,5) // 3D Vertexing with ESD tracks