[u/mrichter/AliRoot.git] / STEER / AliExternalTrackParam.h

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

/* $Id$ */

/*****************************************************************************
 *              "External" track parametrisation class                       *
 *                                                                           *
 *      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 azimuthal angle  *
 *      external param3:   tangent of the track momentum dip angle           *
 *      external param4:   1/pt (1/(GeV/c))                                  *
 *                                                                           *
 * The parameters are estimated at an exact position x in a local coord.     *
 * system rotated by angle alpha with respect to the global coord.system.    *
 *        Origin: I.Belikov, CERN, Jouri.Belikov@cern.ch                     *
 *****************************************************************************/
#include "TMath.h"

#include "AliVTrack.h"

const Double_t kVeryBig=1./kAlmost0;
const Double_t kMostProbablePt=0.35;

class AliVVertex;
class TPolyMarker3D; 

const Double_t kC0max=100*100, // SigmaY<=100cm
               kC2max=100*100, // SigmaZ<=100cm
               kC5max=1*1,     // SigmaSin<=1
               kC9max=1*1,     // SigmaTan<=1
               kC14max=100*100; // Sigma1/Pt<=100 1/GeV

class AliExternalTrackParam: public AliVTrack {
 public:
  AliExternalTrackParam();
  AliExternalTrackParam(const AliExternalTrackParam &);
  AliExternalTrackParam& operator=(const AliExternalTrackParam & trkPar);
  AliExternalTrackParam(Double_t x, Double_t alpha, 
			const Double_t param[5], const Double_t covar[15]);
  AliExternalTrackParam(const AliVTrack *vTrack);
  AliExternalTrackParam(Double_t xyz[3],Double_t pxpypz[3],
			Double_t cv[21],Short_t sign);
  virtual ~AliExternalTrackParam(){}

  template <typename T>
  void Set(T x, T alpha, const T param[5], const T covar[15]) {
    //  Sets the parameters
    fX=x; fAlpha=alpha;
    for (Int_t i = 0; i < 5; i++)  fP[i] = param[i];
    for (Int_t i = 0; i < 15; i++) fC[i] = covar[i];

    CheckCovariance();

  }

  void Set(Double_t xyz[3],Double_t pxpypz[3],Double_t cv[21],Short_t sign);

  static void SetMostProbablePt(Double_t pt) { fgMostProbablePt=pt; }
  static Double_t GetMostProbablePt() { return fgMostProbablePt; }

  void Reset();
  void ResetCovariance(Double_t s2);
  void AddCovariance(const Double_t cov[15]);

  const Double_t *GetParameter() const {return fP;}
  const Double_t *GetCovariance() const {return fC;}

  Double_t GetAlpha() const {return fAlpha;}
  Double_t GetX() const {return fX;}
  Double_t GetY()    const {return fP[0];}
  Double_t GetZ()    const {return fP[1];}
  Double_t GetSnp()  const {return fP[2];}
  Double_t GetTgl()  const {return fP[3];}
  Double_t GetSigned1Pt()  const {return fP[4];}

  Double_t GetSigmaY2() const {return fC[0];}
  Double_t GetSigmaZY() const {return fC[1];}
  Double_t GetSigmaZ2() const {return fC[2];}
  Double_t GetSigmaSnpY() const {return fC[3];}
  Double_t GetSigmaSnpZ() const {return fC[4];}
  Double_t GetSigmaSnp2() const {return fC[5];}
  Double_t GetSigmaTglY() const {return fC[6];}
  Double_t GetSigmaTglZ() const {return fC[7];}
  Double_t GetSigmaTglSnp() const {return fC[8];}
  Double_t GetSigmaTgl2() const {return fC[9];}
  Double_t GetSigma1PtY() const {return fC[10];}
  Double_t GetSigma1PtZ() const {return fC[11];}
  Double_t GetSigma1PtSnp() const {return fC[12];}
  Double_t GetSigma1PtTgl() const {return fC[13];}
  Double_t GetSigma1Pt2() const {return fC[14];}

  // additional functions for AliVParticle
  Double_t Px() const;
  Double_t Py() const;
  Double_t Pz() const { return Pt()*GetTgl(); }
  Double_t Pt() const { return TMath::Abs(GetSignedPt()); }
  Double_t P() const { return GetP(); }
  Bool_t   PxPyPz(Double_t p[3]) const { return GetPxPyPz(p); }
  
  Double_t Xv() const;
  Double_t Yv() const;
  Double_t Zv() const {return GetZ();}
  Bool_t   XvYvZv(Double_t x[3]) const { return GetXYZ(x); }

  Double_t OneOverPt() const { return 1./Pt(); }
  Double_t Phi() const;
  Double_t Theta() const;
  virtual Double_t E() const;
  virtual Double_t M() const;
  Double_t Eta() const;
  virtual Double_t Y() const;
  virtual Short_t  Charge() const { return (Short_t)GetSign(); }
  virtual const Double_t *PID() const { return 0x0; }

  // additional functions from AliVTrack
  virtual Int_t    GetID() const { return -999; }
  virtual UChar_t  GetITSClusterMap() const {return 0; }
  virtual ULong_t  GetStatus() const { return 0; }

  Double_t GetSign() const {return (fP[4]>0) ? 1 : -1;}
  Double_t GetP() const;
  Double_t GetSignedPt() const {
    return (TMath::Abs(fP[4])>kAlmost0) ? 1./fP[4]:TMath::Sign(kVeryBig,fP[4]);
  }
  Double_t Get1P() const;
  virtual Double_t GetC(Double_t b) const {return fP[4]*b*kB2C;}
  void GetDZ(Double_t x,Double_t y,Double_t z,Double_t b,Float_t dz[2]) const; 
  Double_t GetD(Double_t xv, Double_t yv, Double_t b) const; 
  Double_t GetLinearD(Double_t xv, Double_t yv) const; 

  Bool_t CorrectForMeanMaterial(Double_t xOverX0, Double_t xTimesRho, 
        Double_t mass,  Bool_t anglecorr=kFALSE,
	Double_t (*f)(Double_t)=AliExternalTrackParam::BetheBlochSolid);

  Bool_t CorrectForMeanMaterialdEdx(Double_t xOverX0, Double_t xTimesRho, 
	Double_t mass, Double_t dEdx, Bool_t anglecorr=kFALSE);

  Bool_t CorrectForMeanMaterialZA(Double_t xOverX0, Double_t xTimesRho, 
                                  Double_t mass,
                                  Double_t zOverA=0.49848,
                                  Double_t density=2.33,
                                  Double_t exEnergy=173e-9,
                                  Double_t jp1=0.20,
                                  Double_t jp2=3.00,
                                  Bool_t anglecorr=kFALSE
  );

  //
  // Bethe-Bloch formula parameterizations
  //
  static Double_t BetheBlochAleph(Double_t bg,
                                  Double_t kp1=0.76176e-1,
                                  Double_t kp2=10.632,
                                  Double_t kp3=0.13279e-4,
                                  Double_t kp4=1.8631,
                                  Double_t kp5=1.9479
				  );
  static Double_t BetheBlochGeant(Double_t bg,
                                  Double_t kp0=2.33,
                                  Double_t kp1=0.20,
                                  Double_t kp2=3.00,
                                  Double_t kp3=173e-9,
                                  Double_t kp4=0.49848
				  );
    
  static Double_t BetheBlochSolid(Double_t bg);
  static Double_t BetheBlochGas(Double_t bg);

  Double_t GetPredictedChi2(Double_t p[2],Double_t cov[3]) const;

  Double_t 
    GetPredictedChi2(Double_t p[3],Double_t covyz[3],Double_t covxyz[3]) const;

  Double_t GetPredictedChi2(const AliExternalTrackParam *t) const;

  Bool_t 
    PropagateTo(Double_t p[3],Double_t covyz[3],Double_t covxyz[3],Double_t b);

  Double_t *GetResiduals(Double_t *p,Double_t *cov,Bool_t updated=kTRUE) const;
  Bool_t Update(Double_t p[2],Double_t cov[3]);
  Bool_t Rotate(Double_t alpha);
  Bool_t PropagateTo(Double_t x, Double_t b);
  Bool_t Propagate(Double_t alpha, Double_t x, Double_t b);
  Bool_t PropagateBxByBz(Double_t alpha, Double_t x, Double_t b[3]);
  void   Propagate(Double_t len,Double_t x[3],Double_t p[3],Double_t bz) const;
  Bool_t Intersect(Double_t pnt[3], Double_t norm[3], Double_t bz) const;

  static void g3helx3(Double_t qfield, Double_t step, Double_t vect[7]); 
  Bool_t PropagateToBxByBz(Double_t x, const Double_t b[3]);

  void GetHelixParameters(Double_t h[6], Double_t b) const;
  Double_t GetDCA(const AliExternalTrackParam *p, Double_t b,
    Double_t &xthis,Double_t &xp) const;
  Double_t PropagateToDCA(AliExternalTrackParam *p, Double_t b);
  Bool_t PropagateToDCA(const AliVVertex *vtx, Double_t b, Double_t maxd,
                        Double_t dz[2]=0, Double_t cov[3]=0);
  Bool_t PropagateToDCABxByBz(const AliVVertex *vtx, Double_t b[3], 
         Double_t maxd, Double_t dz[2]=0, Double_t cov[3]=0);
  
  void GetDirection(Double_t d[3]) const;
  Bool_t GetPxPyPz(Double_t *p) const;
  Bool_t GetXYZ(Double_t *p) const;
  Bool_t GetCovarianceXYZPxPyPz(Double_t cv[21]) const;
  Bool_t GetPxPyPzAt(Double_t x, Double_t b, Double_t p[3]) const;
  Bool_t GetXYZAt(Double_t x, Double_t b, Double_t r[3]) const;
  Bool_t GetYAt(Double_t x,  Double_t b,  Double_t &y) const;
  Bool_t GetZAt(Double_t x,  Double_t b,  Double_t &z) const;
  void Print(Option_t* option = "") const;
  Double_t GetSnpAt(Double_t x,Double_t b) const;

  //Deprecated
  Bool_t CorrectForMaterial(Double_t d, Double_t x0, Double_t mass,
	 Double_t (*f)(Double_t)=AliExternalTrackParam::BetheBlochSolid);

  Bool_t GetDistance(AliExternalTrackParam *param2, Double_t x, Double_t dist[3], Double_t b);
  Int_t GetIndex(Int_t i, Int_t j) const;
  Int_t GetLabel() const {return -1;} 
  Int_t PdgCode()  const {return 0;}

  //
  // visualization (M. Ivanov)
  //
  virtual void FillPolymarker(TPolyMarker3D *pol, Float_t magf, Float_t minR, Float_t maxR, Float_t stepR);
  virtual void DrawTrack(Float_t magF, Float_t minR, Float_t maxR, Float_t stepR);

  virtual Bool_t Translate(Double_t *vTrasl,Double_t *covV);

  void CheckCovariance();

/*  protected: */
 private:
  Double_t &Par(Int_t i) {return fP[i];}
  Double_t &Cov(Int_t i) {return fC[i];}
  
 private:
  Double32_t           fX;     // X coordinate for the point of parametrisation
  Double32_t           fAlpha; // Local <-->global coor.system rotation angle
  Double32_t           fP[5];  // The track parameters
  Double32_t           fC[15]; // The track parameter covariance matrix

  static Double32_t    fgMostProbablePt; // "Most probable" pt
                                         // (to be used if Bz=0)
  ClassDef(AliExternalTrackParam, 8)
};

inline void AliExternalTrackParam::ResetCovariance(Double_t s2) {
  //
  // Reset the covarince matrix to "something big"
  //

  s2 = TMath::Abs(s2);
  Double_t fC0=fC[0]*s2,
           fC2=fC[2]*s2,
           fC5=fC[5]*s2,
           fC9=fC[9]*s2,
           fC14=fC[14]*s2;
 
  if (fC0>kC0max)  fC0 = kC0max;
  if (fC2>kC2max)  fC2 = kC2max;
  if (fC5>kC5max)  fC5 = kC5max;
  if (fC9>kC9max)  fC9 = kC9max;
  if (fC14>kC14max)  fC14 = kC14max;


    fC[0] = fC0;
    fC[1] = 0.;  fC[2] = fC2;
    fC[3] = 0.;  fC[4] = 0.;  fC[5] = fC5;
    fC[6] = 0.;  fC[7] = 0.;  fC[8] = 0.;  fC[9] = fC9;
    fC[10]= 0.;  fC[11]= 0.;  fC[12]= 0.;  fC[13]= 0.;  fC[14] = fC14;
}


#endif
Commit	Line	Data
	1	#ifndef ALIEXTERNALTRACKPARAM_H
	2	#define ALIEXTERNALTRACKPARAM_H
	3	/* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	4	* See cxx source for full Copyright notice */
	5
	6	/* $Id$ */
	7
	8	/*****************************************************************************
	9	* "External" track parametrisation class *
	10	* *
	11	* external param0: local Y-coordinate of a track (cm) *
	12	* external param1: local Z-coordinate of a track (cm) *
	13	* external param2: local sine of the track momentum azimuthal angle *
	14	* external param3: tangent of the track momentum dip angle *
	15	* external param4: 1/pt (1/(GeV/c)) *
	16	* *
	17	* The parameters are estimated at an exact position x in a local coord. *
	18	* system rotated by angle alpha with respect to the global coord.system. *
	19	* Origin: I.Belikov, CERN, Jouri.Belikov@cern.ch *
	20	*****************************************************************************/
	21	#include "TMath.h"
	22
	23	#include "AliVTrack.h"
	24
	25	const Double_t kVeryBig=1./kAlmost0;
	26	const Double_t kMostProbablePt=0.35;
	27
	28	class AliVVertex;
	29	class TPolyMarker3D;
	30
	31	const Double_t kC0max=100*100, // SigmaY<=100cm
	32	kC2max=100*100, // SigmaZ<=100cm
	33	kC5max=1*1, // SigmaSin<=1
	34	kC9max=1*1, // SigmaTan<=1
	35	kC14max=100*100; // Sigma1/Pt<=100 1/GeV
	36
	37	class AliExternalTrackParam: public AliVTrack {
	38	public:
	39	AliExternalTrackParam();
	40	AliExternalTrackParam(const AliExternalTrackParam &);
	41	AliExternalTrackParam& operator=(const AliExternalTrackParam & trkPar);
	42	AliExternalTrackParam(Double_t x, Double_t alpha,
	43	const Double_t param[5], const Double_t covar[15]);
	44	AliExternalTrackParam(const AliVTrack *vTrack);
	45	AliExternalTrackParam(Double_t xyz[3],Double_t pxpypz[3],
	46	Double_t cv[21],Short_t sign);
	47	virtual ~AliExternalTrackParam(){}
	48
	49	template <typename T>
	50	void Set(T x, T alpha, const T param[5], const T covar[15]) {
	51	// Sets the parameters
	52	fX=x; fAlpha=alpha;
	53	for (Int_t i = 0; i < 5; i++) fP[i] = param[i];
	54	for (Int_t i = 0; i < 15; i++) fC[i] = covar[i];
	55
	56	CheckCovariance();
	57
	58	}
	59
	60	void Set(Double_t xyz[3],Double_t pxpypz[3],Double_t cv[21],Short_t sign);
	61
	62	static void SetMostProbablePt(Double_t pt) { fgMostProbablePt=pt; }
	63	static Double_t GetMostProbablePt() { return fgMostProbablePt; }
	64
	65	void Reset();
	66	void ResetCovariance(Double_t s2);
	67	void AddCovariance(const Double_t cov[15]);
	68
	69	const Double_t *GetParameter() const {return fP;}
	70	const Double_t *GetCovariance() const {return fC;}
	71
	72	Double_t GetAlpha() const {return fAlpha;}
	73	Double_t GetX() const {return fX;}
	74	Double_t GetY() const {return fP[0];}
	75	Double_t GetZ() const {return fP[1];}
	76	Double_t GetSnp() const {return fP[2];}
	77	Double_t GetTgl() const {return fP[3];}
	78	Double_t GetSigned1Pt() const {return fP[4];}
	79
	80	Double_t GetSigmaY2() const {return fC[0];}
	81	Double_t GetSigmaZY() const {return fC[1];}
	82	Double_t GetSigmaZ2() const {return fC[2];}
	83	Double_t GetSigmaSnpY() const {return fC[3];}
	84	Double_t GetSigmaSnpZ() const {return fC[4];}
	85	Double_t GetSigmaSnp2() const {return fC[5];}
	86	Double_t GetSigmaTglY() const {return fC[6];}
	87	Double_t GetSigmaTglZ() const {return fC[7];}
	88	Double_t GetSigmaTglSnp() const {return fC[8];}
	89	Double_t GetSigmaTgl2() const {return fC[9];}
	90	Double_t GetSigma1PtY() const {return fC[10];}
	91	Double_t GetSigma1PtZ() const {return fC[11];}
	92	Double_t GetSigma1PtSnp() const {return fC[12];}
	93	Double_t GetSigma1PtTgl() const {return fC[13];}
	94	Double_t GetSigma1Pt2() const {return fC[14];}
	95
	96	// additional functions for AliVParticle
	97	Double_t Px() const;
	98	Double_t Py() const;
	99	Double_t Pz() const { return Pt()*GetTgl(); }
	100	Double_t Pt() const { return TMath::Abs(GetSignedPt()); }
	101	Double_t P() const { return GetP(); }
	102	Bool_t PxPyPz(Double_t p[3]) const { return GetPxPyPz(p); }
	103
	104	Double_t Xv() const;
	105	Double_t Yv() const;
	106	Double_t Zv() const {return GetZ();}
	107	Bool_t XvYvZv(Double_t x[3]) const { return GetXYZ(x); }
	108
	109	Double_t OneOverPt() const { return 1./Pt(); }
	110	Double_t Phi() const;
	111	Double_t Theta() const;
	112	virtual Double_t E() const;
	113	virtual Double_t M() const;
	114	Double_t Eta() const;
	115	virtual Double_t Y() const;
	116	virtual Short_t Charge() const { return (Short_t)GetSign(); }
	117	virtual const Double_t *PID() const { return 0x0; }
	118
	119	// additional functions from AliVTrack
	120	virtual Int_t GetID() const { return -999; }
	121	virtual UChar_t GetITSClusterMap() const {return 0; }
	122	virtual ULong_t GetStatus() const { return 0; }
	123
	124	Double_t GetSign() const {return (fP[4]>0) ? 1 : -1;}
	125	Double_t GetP() const;
	126	Double_t GetSignedPt() const {
	127	return (TMath::Abs(fP[4])>kAlmost0) ? 1./fP[4]:TMath::Sign(kVeryBig,fP[4]);
	128	}
	129	Double_t Get1P() const;
	130	virtual Double_t GetC(Double_t b) const {return fP[4]bkB2C;}
	131	void GetDZ(Double_t x,Double_t y,Double_t z,Double_t b,Float_t dz[2]) const;
	132	Double_t GetD(Double_t xv, Double_t yv, Double_t b) const;
	133	Double_t GetLinearD(Double_t xv, Double_t yv) const;
	134
	135	Bool_t CorrectForMeanMaterial(Double_t xOverX0, Double_t xTimesRho,
	136	Double_t mass, Bool_t anglecorr=kFALSE,
	137	Double_t (*f)(Double_t)=AliExternalTrackParam::BetheBlochSolid);
	138
	139	Bool_t CorrectForMeanMaterialdEdx(Double_t xOverX0, Double_t xTimesRho,
	140	Double_t mass, Double_t dEdx, Bool_t anglecorr=kFALSE);
	141
	142	Bool_t CorrectForMeanMaterialZA(Double_t xOverX0, Double_t xTimesRho,
	143	Double_t mass,
	144	Double_t zOverA=0.49848,
	145	Double_t density=2.33,
	146	Double_t exEnergy=173e-9,
	147	Double_t jp1=0.20,
	148	Double_t jp2=3.00,
	149	Bool_t anglecorr=kFALSE
	150	);
	151
	152	//
	153	// Bethe-Bloch formula parameterizations
	154	//
	155	static Double_t BetheBlochAleph(Double_t bg,
	156	Double_t kp1=0.76176e-1,
	157	Double_t kp2=10.632,
	158	Double_t kp3=0.13279e-4,
	159	Double_t kp4=1.8631,
	160	Double_t kp5=1.9479
	161	);
	162	static Double_t BetheBlochGeant(Double_t bg,
	163	Double_t kp0=2.33,
	164	Double_t kp1=0.20,
	165	Double_t kp2=3.00,
	166	Double_t kp3=173e-9,
	167	Double_t kp4=0.49848
	168	);
	169
	170	static Double_t BetheBlochSolid(Double_t bg);
	171	static Double_t BetheBlochGas(Double_t bg);
	172
	173	Double_t GetPredictedChi2(Double_t p[2],Double_t cov[3]) const;
	174
	175	Double_t
	176	GetPredictedChi2(Double_t p[3],Double_t covyz[3],Double_t covxyz[3]) const;
	177
	178	Double_t GetPredictedChi2(const AliExternalTrackParam *t) const;
	179
	180	Bool_t
	181	PropagateTo(Double_t p[3],Double_t covyz[3],Double_t covxyz[3],Double_t b);
	182
	183	Double_t GetResiduals(Double_t p,Double_t *cov,Bool_t updated=kTRUE) const;
	184	Bool_t Update(Double_t p[2],Double_t cov[3]);
	185	Bool_t Rotate(Double_t alpha);
	186	Bool_t PropagateTo(Double_t x, Double_t b);
	187	Bool_t Propagate(Double_t alpha, Double_t x, Double_t b);
	188	Bool_t PropagateBxByBz(Double_t alpha, Double_t x, Double_t b[3]);
	189	void Propagate(Double_t len,Double_t x[3],Double_t p[3],Double_t bz) const;
	190	Bool_t Intersect(Double_t pnt[3], Double_t norm[3], Double_t bz) const;
	191
	192	static void g3helx3(Double_t qfield, Double_t step, Double_t vect[7]);
	193	Bool_t PropagateToBxByBz(Double_t x, const Double_t b[3]);
	194
	195	void GetHelixParameters(Double_t h[6], Double_t b) const;
	196	Double_t GetDCA(const AliExternalTrackParam *p, Double_t b,
	197	Double_t &xthis,Double_t &xp) const;
	198	Double_t PropagateToDCA(AliExternalTrackParam *p, Double_t b);
	199	Bool_t PropagateToDCA(const AliVVertex *vtx, Double_t b, Double_t maxd,
	200	Double_t dz[2]=0, Double_t cov[3]=0);
	201	Bool_t PropagateToDCABxByBz(const AliVVertex *vtx, Double_t b[3],
	202	Double_t maxd, Double_t dz[2]=0, Double_t cov[3]=0);
	203
	204	void GetDirection(Double_t d[3]) const;
	205	Bool_t GetPxPyPz(Double_t *p) const;
	206	Bool_t GetXYZ(Double_t *p) const;
	207	Bool_t GetCovarianceXYZPxPyPz(Double_t cv[21]) const;
	208	Bool_t GetPxPyPzAt(Double_t x, Double_t b, Double_t p[3]) const;
	209	Bool_t GetXYZAt(Double_t x, Double_t b, Double_t r[3]) const;
	210	Bool_t GetYAt(Double_t x, Double_t b, Double_t &y) const;
	211	Bool_t GetZAt(Double_t x, Double_t b, Double_t &z) const;
	212	void Print(Option_t* option = "") const;
	213	Double_t GetSnpAt(Double_t x,Double_t b) const;
	214
	215	//Deprecated
	216	Bool_t CorrectForMaterial(Double_t d, Double_t x0, Double_t mass,
	217	Double_t (*f)(Double_t)=AliExternalTrackParam::BetheBlochSolid);
	218
	219	Bool_t GetDistance(AliExternalTrackParam *param2, Double_t x, Double_t dist[3], Double_t b);
	220	Int_t GetIndex(Int_t i, Int_t j) const;
	221	Int_t GetLabel() const {return -1;}
	222	Int_t PdgCode() const {return 0;}
	223
	224	//
	225	// visualization (M. Ivanov)
	226	//
	227	virtual void FillPolymarker(TPolyMarker3D *pol, Float_t magf, Float_t minR, Float_t maxR, Float_t stepR);
	228	virtual void DrawTrack(Float_t magF, Float_t minR, Float_t maxR, Float_t stepR);
	229
	230	virtual Bool_t Translate(Double_t vTrasl,Double_t covV);
	231
	232	void CheckCovariance();
	233
	234	/* protected: */
	235	private:
	236	Double_t &Par(Int_t i) {return fP[i];}
	237	Double_t &Cov(Int_t i) {return fC[i];}
	238
	239	private:
	240	Double32_t fX; // X coordinate for the point of parametrisation
	241	Double32_t fAlpha; // Local <-->global coor.system rotation angle
	242	Double32_t fP[5]; // The track parameters
	243	Double32_t fC[15]; // The track parameter covariance matrix
	244
	245	static Double32_t fgMostProbablePt; // "Most probable" pt
	246	// (to be used if Bz=0)
	247	ClassDef(AliExternalTrackParam, 8)
	248	};
	249
	250	inline void AliExternalTrackParam::ResetCovariance(Double_t s2) {
	251	//
	252	// Reset the covarince matrix to "something big"
	253	//
	254
	255	s2 = TMath::Abs(s2);
	256	Double_t fC0=fC[0]*s2,
	257	fC2=fC[2]*s2,
	258	fC5=fC[5]*s2,
	259	fC9=fC[9]*s2,
	260	fC14=fC[14]*s2;
	261
	262	if (fC0>kC0max) fC0 = kC0max;
	263	if (fC2>kC2max) fC2 = kC2max;
	264	if (fC5>kC5max) fC5 = kC5max;
	265	if (fC9>kC9max) fC9 = kC9max;
	266	if (fC14>kC14max) fC14 = kC14max;
	267
	268
	269	fC[0] = fC0;
	270	fC[1] = 0.; fC[2] = fC2;
	271	fC[3] = 0.; fC[4] = 0.; fC[5] = fC5;
	272	fC[6] = 0.; fC[7] = 0.; fC[8] = 0.; fC[9] = fC9;
	273	fC[10]= 0.; fC[11]= 0.; fC[12]= 0.; fC[13]= 0.; fC[14] = fC14;
	274	}
	275
	276
	277
	278
	279	#endif