3 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
6 //-------------------------------------------------------
9 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
10 //-------------------------------------------------------
12 /*****************************************************************************
14 * Internal view of the TPC track parametrisation as well as the order of *
15 * track parameters are subject for possible changes ! *
16 * Use GetExternalParameters() and GetExternalCovariance() to access TPC *
17 * track information regardless of its internal representation. *
18 * This formation is now fixed in the following way: *
19 * external param0: local Y-coordinate of a track (cm) *
20 * external param1: local Z-coordinate of a track (cm) *
21 * external param2: local sine of the track momentum azimuth angle *
22 * external param3: tangent of the track momentum dip angle *
23 * external param4: 1/pt (1/(GeV/c)) *
24 *****************************************************************************/
26 #include <AliKalmanTrack.h>
29 #include "AliTPCreco.h"
31 class AliTPCClustersArray;
34 //_____________________________________________________________________________
35 class AliTPCtrack : public AliKalmanTrack {
37 AliTPCtrack():AliKalmanTrack(){}
38 AliTPCtrack(UInt_t index, const Double_t xx[5],
39 const Double_t cc[15], Double_t xr, Double_t alpha);
40 AliTPCtrack(const AliKalmanTrack& t, Double_t alpha);
41 AliTPCtrack(const AliTPCtrack& t);
42 Int_t PropagateToVertex(Double_t x0=36.66,Double_t rho=1.2e-3);
43 Int_t Rotate(Double_t angle);
44 void SetdEdx(Double_t dedx) {fdEdx=dedx;}
46 Double_t GetX() const {return fX;}
47 Double_t GetAlpha() const {return fAlpha;}
48 Double_t GetdEdx() const {return fdEdx;}
50 Double_t GetY() const {return fP0;}
51 Double_t GetZ() const {return fP1;}
52 Double_t GetSnp() const {return fX*fP4 - fP2;}
54 Get1Pt() const { return (1e-9*TMath::Abs(fP4)/fP4 + fP4)*GetConvConst(); }
55 Double_t GetTgl() const {return fP3;}
57 Double_t GetSigmaY2() const {return fC00;}
58 Double_t GetSigmaZ2() const {return fC11;}
60 Int_t Compare(const TObject *o) const;
62 void GetExternalParameters(Double_t& xr, Double_t x[5]) const ;
63 void GetExternalCovariance(Double_t cov[15]) const ;
65 Int_t GetClusterIndex(Int_t i) const {return fIndex[i];}
67 //******** To be removed next release !!! **************
68 Double_t GetEta() const {return fP2;}
69 Double_t GetC() const {return fP4;}
70 void GetCovariance(Double_t cc[15]) const {
72 cc[1 ]=fC10; cc[2 ]=fC11;
73 cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22;
74 cc[6 ]=fC40; cc[7 ]=fC41; cc[8 ]=fC42; cc[9 ]=fC44;
75 cc[10]=fC30; cc[11]=fC31; cc[12]=fC32; cc[13]=fC43; cc[14]=fC33;
77 //******************************************************
79 virtual Double_t GetPredictedChi2(const AliCluster *cluster) const;
80 Int_t PropagateTo(Double_t xr,Double_t x0=28.94,Double_t rho=0.9e-3);
81 Int_t Update(const AliCluster* c, Double_t chi2, UInt_t i);
82 void ResetCovariance();
85 Double_t fX; // X-coordinate of this track (reference plane)
86 Double_t fAlpha; // Rotation angle the local (TPC sector)
87 // coordinate system and the global ALICE one.
89 Double_t fdEdx; // dE/dx
91 Double_t fP0; // Y-coordinate of a track
92 Double_t fP1; // Z-coordinate of a track
94 Double_t fP3; // tangent of the track momentum dip angle
95 Double_t fP4; // track curvature
97 Double_t fC00; // covariance
98 Double_t fC10, fC11; // matrix
99 Double_t fC20, fC21, fC22; // of the
100 Double_t fC30, fC31, fC32, fC33; // track
101 Double_t fC40, fC41, fC42, fC43, fC44; // parameters
103 UInt_t fIndex[kMaxRow]; // indices of associated clusters
105 ClassDef(AliTPCtrack,1) // Time Projection Chamber reconstructed tracks
109 void AliTPCtrack::GetExternalParameters(Double_t& xr, Double_t x[5]) const {
110 //---------------------------------------------------------------------
111 // This function return external TPC track representation
112 //---------------------------------------------------------------------
114 x[0]=GetY(); x[1]=GetZ(); x[2]=GetSnp(); x[3]=GetTgl(); x[4]=Get1Pt();