Tracking in non-uniform nmagnetic field (Yu.Belikov)
[u/mrichter/AliRoot.git] / ITS / AliITSVertexerTracks.h
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cab6ff9b 1#ifndef ALIITSVERTEXERTRACKS_H
2#define ALIITSVERTEXERTRACKS_H
3/* Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
5
6
7//-------------------------------------------------------
8// Class for primary vertex determination with ITS tracks
9//
10// Origin: A.Dainese, Padova, andrea.dainese@pd.infn.it
11// M.Masera, Torino, massimo.masera@to.infn.it
12//-------------------------------------------------------
13
14/*****************************************************************************
15 * *
16 * This class determines the primary vertex position using ITS tracks. *
17 * This is done in two steps: *
18 * 1) Vertex Finding: a reasonable estimate of the vertex position is *
19 * obtained from a mean of "points of closest approach" between all *
20 * possible pairs of tracks. *
21 * 2) Vertex Fitting: once tracks are propagated to the position given by *
22 * first step, the optimal estimate of the position of vertex is obtained *
23 * from a weighted average of the track positions. A covariance *
24 * matrix and a chi2 for the vertex are given. *
25 * *
26 *****************************************************************************/
27
28#include "AliKalmanTrack.h"
29#include "AliITSVertexer.h"
30
3a4956bf 31#include <TObjArray.h>
32
cab6ff9b 33class TTree;
d681bb2d 34class AliESDVertex;
a48d1ed3 35class AliESD;
cab6ff9b 36
37class AliITSVertexerTracks : public AliITSVertexer {
38
39 public:
40 // default constructor
41 AliITSVertexerTracks();
42 // standard constructor
11ba84a4 43 AliITSVertexerTracks(TFile *inFile,TFile *outFile,
c84a5e9e 44 const AliMagF *map,Int_t fEv=0,Int_t lEv=0,
11ba84a4 45 Double_t xStart=0.,Double_t yStart=0.);
46 // alternative constructor
c84a5e9e 47 AliITSVertexerTracks(const AliMagF *map, TString fn,
11ba84a4 48 Double_t xStart=0,Double_t yStart=0);
cab6ff9b 49 // destructor
a48d1ed3 50 virtual ~AliITSVertexerTracks();
cab6ff9b 51 // return vertex from the set of tracks in the tree
d681bb2d 52 AliESDVertex* VertexOnTheFly(TTree &trkTree);
cab6ff9b 53 // computes the vertex for the current event
d681bb2d 54 virtual AliESDVertex* FindVertexForCurrentEvent(Int_t evnumb);
11ba84a4 55 // computes the vertex for the current event using the ESD
d681bb2d 56 AliESDVertex* FindVertexForCurrentEvent(AliESD *esdEvent);
88cb7938 57 // computes the vertex for each event and stores it on file
cab6ff9b 58 virtual void FindVertices();
11ba84a4 59 // computes the vertex for each event and stores it in the ESD
60 void FindVerticesESD();
cab6ff9b 61 virtual void PrintStatus() const;
c84a5e9e 62 void SetFieldMap(const AliMagF *map)const{AliKalmanTrack::SetFieldMap(map);}
11ba84a4 63 void SetMinTracks(Int_t n=2) { fMinTracks = n; return; }
64 void SetSkipTracks(Int_t n,Int_t *skipped);
cab6ff9b 65 void SetVtxStart(Double_t x=0,Double_t y=0)
66 { fNominalPos[0]=x; fNominalPos[1]=y; return; }
67
68 private:
a48d1ed3 69 // copy constructor (NO copy allowed: the constructor is protected
70 // to avoid misuse)
71 AliITSVertexerTracks(const AliITSVertexerTracks& vtxr);
72 // assignment operator (NO assignment allowed)
73 AliITSVertexerTracks& operator=(const AliITSVertexerTracks& /* vtxr */);
11ba84a4 74 TFile *fInFile; // input file (with tracks)
75 TFile *fOutFile; // output file for vertices
cab6ff9b 76 Double_t fInitPos[3]; // vertex position after vertex finder
77 Double_t fNominalPos[2]; // initial knowledge on vertex position
78 Int_t fMinTracks; // minimum number of tracks
79 Double_t fMaxChi2PerTrack; // maximum contribition to the chi2
cab6ff9b 80 TObjArray fTrkArray; // array with tracks to be processed
81 Int_t *fTrksToSkip; // tracks to be skipped for find and fit
82 Int_t fNTrksToSkip; // number of tracks to be skipped
83
84 Bool_t CheckField() const;
85 void ComputeMaxChi2PerTrack(Int_t nTracks);
86 Int_t PrepareTracks(TTree &trkTree);
cab6ff9b 87 void TooFewTracks();
88 void VertexFinder();
89 void VertexFitter();
90
91 ClassDef(AliITSVertexerTracks,1) // 3D Vertexing with ITS tracks
92};
93
94#endif
95
96
97