Setting arbitrary Magnetic field while track reading

[u/mrichter/AliRoot.git] / TPC / AliTPCtrack.h

#ifndef ALITPCTRACK_H
#define ALITPCTRACK_H
/* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 * See cxx source for full Copyright notice                               */

/* $Id$ */



//-------------------------------------------------------
//                    TPC Track Class
//
//   Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch 
//-------------------------------------------------------

/*****************************************************************************
 *                          December 18, 2000                                *
 *  Internal view of the TPC track parametrisation as well as the order of   *
 *           track parameters are subject for possible changes !             *
 *  Use GetExternalParameters() and GetExternalCovariance() to access TPC    *
 *      track information regardless of its internal representation.         *
 * This formation is now fixed in the following way:                         *
 *      external param0:   local Y-coordinate of a track (cm)                *
 *      external param1:   local Z-coordinate of a track (cm)                *
 *      external param2:   local sine of the track momentum azimuth angle    *
 *      external param3:   tangent of the track momentum dip angle           *
 *      external param4:   1/pt (1/(GeV/c))                                  *
 *****************************************************************************/

#include <AliKalmanTrack.h>
#include <TMath.h>

#include "AliTPCreco.h"

class AliBarrelTrack;

//_____________________________________________________________________________
class AliTPCtrack : public AliKalmanTrack {
public:
  AliTPCtrack();
  AliTPCtrack(UInt_t index, const Double_t xx[5], 
              const Double_t cc[15], Double_t xr, Double_t alpha); 
  AliTPCtrack(const AliKalmanTrack& t, Double_t alpha);
  AliTPCtrack(const AliTPCtrack& t);
  virtual ~AliTPCtrack() {}
  Int_t PropagateToVertex(Double_t x0=36.66,Double_t rho=1.2e-3);
  Int_t Rotate(Double_t angle);
  void SetdEdx(Double_t dedx) {fdEdx=dedx;}

  Double_t GetX()     const {return fX;}
  Double_t GetAlpha() const {return fAlpha;}
  Double_t GetdEdx()  const {return fdEdx;}

  Double_t GetY()   const {return fP0;}
  Double_t GetZ()   const {return fP1;}
  Double_t GetSnp() const {return fX*fP4 - fP2;}             
  Double_t 
    Get1Pt() const { return (1e-9*TMath::Abs(fP4)/fP4 + fP4)*GetConvConst(); }
  Double_t GetTgl() const {return fP3;}

  Double_t GetSigmaY2() const {return fC00;}
  Double_t GetSigmaZ2() const {return fC11;}

// Some methods useful for users. Implementation is not
// optimized for speed but for minimal maintanance effort
  Double_t Phi() const;
  Double_t Theta() const {return TMath::Pi()/2.-TMath::ATan(GetTgl());}
  Double_t Px() const {return TMath::Cos(Phi())/TMath::Abs(Get1Pt());}
  Double_t Py() const {return TMath::Sin(Phi())/TMath::Abs(Get1Pt());}
  Double_t Pz() const {return GetTgl()/TMath::Abs(Get1Pt());}
  Double_t Pt() const {return 1./TMath::Abs(Get1Pt());}
  Double_t P() const {return TMath::Sqrt(Pt()*Pt()+Pz()*Pz());}

  Int_t Compare(const TObject *o) const;

  void GetExternalParameters(Double_t& xr, Double_t x[5]) const ;
  void GetExternalCovariance(Double_t cov[15]) const ;

  // [SR, 01.04.2003]

  void GetBarrelTrack(AliBarrelTrack *track);

  void ResetNWrong() {fNWrong = 0;}
  void ResetNRotation() {fNRotation = 0;}
  
  Int_t GetNWrong() const {return fNWrong;}
  Int_t GetNRotation() const {return fNRotation;}

  Int_t GetNumber() const {return fNumber;}
  void  SetNumber(Int_t n) {fNumber = n;} 
  //

  Int_t GetClusterIndex(Int_t i) const {return fIndex[i];}

//******** To be removed next release !!! **************
  Double_t GetEta() const {return fP2;}
  Double_t GetC()   const {return fP4;}
  void GetCovariance(Double_t cc[15]) const {
    cc[0 ]=fC00;
    cc[1 ]=fC10;  cc[2 ]=fC11;
    cc[3 ]=fC20;  cc[4 ]=fC21;  cc[5 ]=fC22;
    cc[6 ]=fC40;  cc[7 ]=fC41;  cc[8 ]=fC42;  cc[9 ]=fC44;
    cc[10]=fC30;  cc[11]=fC31;  cc[12]=fC32;  cc[13]=fC43;  cc[14]=fC33;
  }  
//****************************************************** 

  virtual Double_t GetPredictedChi2(const AliCluster *cluster) const;
  Int_t PropagateTo(Double_t xr,Double_t x0=28.94,Double_t rho=0.9e-3);
  Int_t Update(const AliCluster* c, Double_t chi2, UInt_t i);
  void ResetCovariance();

protected: 
  Double_t fX;              // X-coordinate of this track (reference plane)
  Double_t fAlpha;          // Rotation angle the local (TPC sector)
                            // coordinate system and the global ALICE one.

  Double_t fdEdx;           // dE/dx

  Double_t fP0;             // Y-coordinate of a track
  Double_t fP1;             // Z-coordinate of a track
  Double_t fP2;             // C*x0
  Double_t fP3;             // tangent of the track momentum dip angle
  Double_t fP4;             // track curvature

  Double_t fC00;                         // covariance
  Double_t fC10, fC11;                   // matrix
  Double_t fC20, fC21, fC22;             // of the
  Double_t fC30, fC31, fC32, fC33;       // track
  Double_t fC40, fC41, fC42, fC43, fC44; // parameters
 
  UInt_t fIndex[kMaxRow];       // indices of associated clusters 

  //[SR, 01.04.2003]
  Int_t fNWrong;         // number of wrong clusters
  Int_t fNRotation;      // number of rotations
  Int_t fNumber;         // magic number used for number of clusters

  ClassDef(AliTPCtrack,1)   // Time Projection Chamber reconstructed tracks
};

inline 
void AliTPCtrack::GetExternalParameters(Double_t& xr, Double_t x[5]) const {
  //---------------------------------------------------------------------
  // This function return external TPC track representation
  //---------------------------------------------------------------------
     xr=fX;          
     x[0]=GetY(); x[1]=GetZ(); x[2]=GetSnp(); x[3]=GetTgl(); x[4]=Get1Pt();
}

#endif