[u/mrichter/AliRoot.git] / HMPID / AliHMPIDtrack.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

#include "AliESDtrack.h" 
#include "AliTracker.h" 
#include "AliHMPIDtrack.h" 
#include "AliPID.h" 

ClassImp(AliHMPIDtrack)

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AliHMPIDtrack::AliHMPIDtrack():AliKalmanTrack()
{
  //
  // def. ctor
  //
}                                
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AliHMPIDtrack::AliHMPIDtrack(const AliHMPIDtrack& t):AliKalmanTrack(t)
{
  //
  // cctor.
  //
 }                                
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AliHMPIDtrack::AliHMPIDtrack(const AliESDtrack& t):AliKalmanTrack()
{
  //
  // Constructor from AliESDtrack
  //
  SetLabel(t.GetLabel());
  SetChi2(0.);
  SetMass(t.GetMassForTracking());

  Set(t.GetX(),t.GetAlpha(),t.GetParameter(),t.GetCovariance());

  if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
  StartTimeIntegral();
  Double_t times[AliPID::kSPECIESC]; 
  t.GetIntegratedTimes(times,AliPID::kSPECIESC); SetIntegratedTimes(times);
  SetIntegratedLength(t.GetIntegratedLength());
}              
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AliHMPIDtrack& AliHMPIDtrack::operator=(const AliHMPIDtrack &/*source*/)
{
  // ass. op.
  
  return *this;
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDtrack::PropagateTo(Double_t xk, Double_t xx0, Double_t xrho)
{
  //
  // Propagates this track to a reference plane defined by "xk" [cm] 
  // correcting for the mean crossed material.
  // Arguments:
  // "xx0"  - thickness/rad.length [units of the radiation length] 
  // "xrho" - thickness*density    [g/cm^2] 
  //  Returns: kTRUE if the track propagates to plane, else kFALSE
 
  if (xk == GetX()) {
    return kTRUE;
  }
  Double_t b[3]; GetBxByBz(b);
  if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) {
    return kFALSE;
  }
  if (!AliExternalTrackParam::CorrectForMeanMaterial(xx0,xrho,GetMass())) { 
    return kFALSE;
  }
  return kTRUE;            
}//PropagateTo()  
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDtrack::Rotate(Double_t alpha, Bool_t absolute)
{
  //
  // Rotates track parameters in R*phi plane
  // if absolute rotation alpha is in global system
  // otherwise alpha rotation is relative to the current rotation angle
  //  

  if (absolute) {
    alpha -= GetAlpha();
  }
 

  return AliExternalTrackParam::Rotate(GetAlpha()+alpha);

}   
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++  
Int_t AliHMPIDtrack::GetProlongation(Double_t xk, Double_t &y, Double_t &z)
{
  //
  // Find a prolongation at given x
  // Return 0 if it does not exist
  //  

  Double_t bz = GetBz();

  if (!AliExternalTrackParam::GetYAt(xk,bz,y)) {
    return 0;
  }
  if (!AliExternalTrackParam::GetZAt(xk,bz,z)) {
    return 0;
  }

  return 1;  

}
 
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t   AliHMPIDtrack::PropagateToR(Double_t r,Double_t step)
{
  //
  // Propagate track to the radial position
  // Rotation always connected to the last track position
  //

  Double_t xyz0[3];
  Double_t xyz1[3];
  Double_t y;
  Double_t z; 

  Double_t radius = TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
  // Direction +-
  Double_t dir    = (radius > r) ? -1.0 : 1.0;   

  for (Double_t x = radius+dir*step; dir*x < dir*r; x += dir*step) {

    GetXYZ(xyz0);	
    Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
    if(!Rotate(alpha,kTRUE)) return kFALSE;
    GetXYZ(xyz0);	
    if (!GetProlongation(x,y,z)) return kFALSE;
    xyz1[0] = x * TMath::Cos(alpha) + y * TMath::Sin(alpha); 
    xyz1[1] = x * TMath::Sin(alpha) - y * TMath::Cos(alpha);
    xyz1[2] = z;
    Double_t param[7];
    AliTracker::MeanMaterialBudget(xyz0,xyz1,param);
    if (param[1] <= 0) {
      param[1] = 100000000;
    }
    PropagateTo(x,param[1],param[0]*param[4]);

  } 

  GetXYZ(xyz0);	
  Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
  if(!Rotate(alpha,kTRUE)) return kFALSE;
  GetXYZ(xyz0);	
  if (!GetProlongation(r,y,z)) return kFALSE;
  xyz1[0] = r * TMath::Cos(alpha) + y * TMath::Sin(alpha); 
  xyz1[1] = r * TMath::Sin(alpha) - y * TMath::Cos(alpha);
  xyz1[2] = z;
  Double_t param[7];
  AliTracker::MeanMaterialBudget(xyz0,xyz1,param);

  if (param[1] <= 0) {
    param[1] = 100000000;
  }
 
  return PropagateTo(r,param[1],param[0]*param[4]);
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Double_t AliHMPIDtrack::GetPredictedChi2(const AliCluster3D *c) const {
  //
  // Arguments: AliCluster3D
  // Returns:   Chi2 of track for the cluster
  Double_t      p[3]={c->GetX(),       c->GetY(),       c->GetZ()};
  Double_t  covyz[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
  Double_t covxyz[3]={c->GetSigmaX2(), c->GetSigmaXY(), c->GetSigmaXZ()};
  return AliExternalTrackParam::GetPredictedChi2(p, covyz, covxyz);
}//GetPredictedChi2()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDtrack::PropagateTo(const AliCluster3D *c) {
  //
  // Arguments: AliCluster3D
  // Returns: kTRUE if the track propagates to the plane of the cluster
  Double_t      oldX=GetX(),   oldY=GetY(), oldZ=GetZ();
  Double_t      p[3]={c->GetX(), c->GetY(), c->GetZ()};
  Double_t  covyz[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
  Double_t covxyz[3]={c->GetSigmaX2(), c->GetSigmaXY(), c->GetSigmaXZ()};
  Double_t bz=-GetBz();
    
  if(!AliExternalTrackParam::PropagateTo(p, covyz, covxyz, bz)) return kFALSE;
  if(IsStartedTimeIntegral()) 
    {
      Double_t d = TMath::Sqrt((GetX()-oldX)*(GetX()-oldX) + (GetY()-oldY)*(GetY()-oldY) + (GetZ()-oldZ)*(GetZ()-oldZ));
      if (GetX()<oldX) d=-d;
      AddTimeStep(d);
    }
  return kTRUE;
}//PropagateTo()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDtrack::Intersect(Double_t pnt[3], Double_t norm[3]) const {
  //+++++++++++++++++++++++++++++++++++++++++    
  // Origin: K. Shileev (Kirill.Shileev@cern.ch)
  // Finds point of intersection (if exists) of the helix with the plane. 
  // Stores result in fX and fP.   
  // Arguments: planePoint,planeNorm - the plane defined by any plane's point 
  // and vector, normal to the plane
  // Returns: kTrue if helix intersects the plane, kFALSE otherwise.
  //+++++++++++++++++++++++++++++++++++++++++    
  Double_t x0[3]; GetXYZ(x0); //get track position in MARS
  
  //estimates initial helix length up to plane
  Double_t s=(pnt[0]-x0[0])*norm[0] + (pnt[1]-x0[1])*norm[1] + (pnt[2]-x0[2])*norm[2];
  Double_t dist=99999,distPrev=dist;
  Double_t p[3],x[3]; 
  while(TMath::Abs(dist)>0.00001){
    //calculates helix at the distance s from x0 ALONG the helix
    Propagate(s,x,p);
    //distance between current helix position and plane
    dist=(x[0]-pnt[0])*norm[0]+(x[1]-pnt[1])*norm[1]+(x[2]-pnt[2])*norm[2];  
    if(TMath::Abs(dist) >= TMath::Abs(distPrev)) {return kFALSE;}
    distPrev=dist;
    s-=dist;
  }
  //on exit pnt is intersection point,norm is track vector at that point, 
  //all in MARS
  for (Int_t i=0; i<3; i++) {pnt[i]=x[i]; norm[i]=p[i];}
  return kTRUE;
}//Intersect()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
void AliHMPIDtrack::Propagate(Double_t len, Double_t x[3],Double_t p[3]) const {
  //+++++++++++++++++++++++++++++++++++++++++    
  // Origin: K. Shileev (Kirill.Shileev@cern.ch)
  // Extrapolate track along simple helix in magnetic field
  // Arguments: len -distance alogn helix, [cm]
  //            bz  - mag field, [kGaus]   
  // Returns: x and p contain extrapolated positon and momentum  
  // The momentum returned for straight-line tracks is meaningless !
  //+++++++++++++++++++++++++++++++++++++++++    
  GetXYZ(x);    
  Double_t bField[3];
  TGeoGlobalMagField::Instance()->Field(x,bField);
  Double_t bz = -bField[2];
  if (OneOverPt() < kAlmost0 || TMath::Abs(bz) < kAlmost0Field ){ //straight-line tracks
     Double_t unit[3]; GetDirection(unit);
     x[0]+=unit[0]*len;   
     x[1]+=unit[1]*len;   
     x[2]+=unit[2]*len;

     p[0]=unit[0]/kAlmost0;   
     p[1]=unit[1]/kAlmost0;   
     p[2]=unit[2]/kAlmost0;   
  } else {
     GetPxPyPz(p);
     Double_t pp=GetP();
     Double_t a = -kB2C*bz*GetSign(); ////////// what is kB2C
     Double_t rho = a/pp;
     x[0] += p[0]*TMath::Sin(rho*len)/a - p[1]*(1-TMath::Cos(rho*len))/a;
     x[1] += p[1]*TMath::Sin(rho*len)/a + p[0]*(1-TMath::Cos(rho*len))/a;
     x[2] += p[2]*len/pp;
     Double_t p0=p[0];
     p[0] = p0  *TMath::Cos(rho*len) - p[1]*TMath::Sin(rho*len);
     p[1] = p[1]*TMath::Cos(rho*len) + p0  *TMath::Sin(rho*len);
  }
}//Propagate()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDtrack::Update(const AliHMPIDCluster *pClu, Double_t /*chisq*/, Int_t /*index*/)
{
  //
  // Arguments: AliCluster3D, chi sq, and clu index
  // Returns: kTRUE if the track parameters are successfully updated
  Double_t p[2]={pClu->GetY(), pClu->GetZ()};
  Double_t cov[3]={pClu->GetSigmaY2(), 0., pClu->GetSigmaZ2()};
  if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;

  /*
  AliTracker::FillResiduals(this,p,cov,pClu->GetVolumeId());

  Int_t n=GetNumberOfClusters();
  fIndex[n]=index;
  SetNumberOfClusters(n+1);
  SetChi2(GetChi2()+chisq);
*/
  return kTRUE;

}//Update()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Commit	Line	Data
83253968	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15
	16	#include "AliESDtrack.h"
	17	#include "AliTracker.h"
	18	#include "AliHMPIDtrack.h"
fc9b31a7	19	#include "AliPID.h"
83253968	20
	21	ClassImp(AliHMPIDtrack)
	22
	23	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	24	AliHMPIDtrack::AliHMPIDtrack():AliKalmanTrack()
	25	{
	26	//
	27	// def. ctor
	28	//
	29	}
	30	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	31	AliHMPIDtrack::AliHMPIDtrack(const AliHMPIDtrack& t):AliKalmanTrack(t)
	32	{
	33	//
	34	// cctor.
	35	//
	36	}
	37	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	38	AliHMPIDtrack::AliHMPIDtrack(const AliESDtrack& t):AliKalmanTrack()
	39	{
	40	//
	41	// Constructor from AliESDtrack
	42	//
	43	SetLabel(t.GetLabel());
	44	SetChi2(0.);
1d26da6d	45	SetMass(t.GetMassForTracking());
83253968	46
	47	Set(t.GetX(),t.GetAlpha(),t.GetParameter(),t.GetCovariance());
	48
	49	if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
	50	StartTimeIntegral();
fc9b31a7	51	Double_t times[AliPID::kSPECIESC];
fc9b31a7	52	t.GetIntegratedTimes(times,AliPID::kSPECIESC); SetIntegratedTimes(times);
83253968	53	SetIntegratedLength(t.GetIntegratedLength());
	54	}
	55	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	56	AliHMPIDtrack& AliHMPIDtrack::operator=(const AliHMPIDtrack &/source/)
	57	{
	58	// ass. op.
	59
	60	return *this;
	61	}
	62	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	63	Bool_t AliHMPIDtrack::PropagateTo(Double_t xk, Double_t xx0, Double_t xrho)
	64	{
	65	//
	66	// Propagates this track to a reference plane defined by "xk" [cm]
	67	// correcting for the mean crossed material.
	68	// Arguments:
	69	// "xx0" - thickness/rad.length [units of the radiation length]
	70	// "xrho" - thickness*density [g/cm^2]
	71	// Returns: kTRUE if the track propagates to plane, else kFALSE
	72
	73	if (xk == GetX()) {
	74	return kTRUE;
	75	}
87a6d94b	76	Double_t b[3]; GetBxByBz(b);
87a6d94b	77	if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) {
83253968	78	return kFALSE;
	79	}
	80	if (!AliExternalTrackParam::CorrectForMeanMaterial(xx0,xrho,GetMass())) {
	81	return kFALSE;
	82	}
	83	return kTRUE;
	84	}//PropagateTo()
	85	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	86	Bool_t AliHMPIDtrack::Rotate(Double_t alpha, Bool_t absolute)
	87	{
	88	//
	89	// Rotates track parameters in R*phi plane
	90	// if absolute rotation alpha is in global system
	91	// otherwise alpha rotation is relative to the current rotation angle
	92	//
	93
	94	if (absolute) {
	95	alpha -= GetAlpha();
	96	}
	97
	98
	99	return AliExternalTrackParam::Rotate(GetAlpha()+alpha);
	100
	101	}
	102	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	103	Int_t AliHMPIDtrack::GetProlongation(Double_t xk, Double_t &y, Double_t &z)
	104	{
	105	//
	106	// Find a prolongation at given x
	107	// Return 0 if it does not exist
	108	//
	109
87a6d94b	110	Double_t bz = GetBz();
83253968	111
	112	if (!AliExternalTrackParam::GetYAt(xk,bz,y)) {
	113	return 0;
	114	}
	115	if (!AliExternalTrackParam::GetZAt(xk,bz,z)) {
	116	return 0;
	117	}
	118
	119	return 1;
	120
	121	}
	122
	123	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
496c71b0	124	Bool_t AliHMPIDtrack::PropagateToR(Double_t r,Double_t step)
83253968	125	{
	126	//
	127	// Propagate track to the radial position
	128	// Rotation always connected to the last track position
	129	//
	130
	131	Double_t xyz0[3];
	132	Double_t xyz1[3];
	133	Double_t y;
	134	Double_t z;
	135
	136	Double_t radius = TMath::Sqrt(GetX()GetX() + GetY()GetY());
	137	// Direction +-
	138	Double_t dir = (radius > r) ? -1.0 : 1.0;
	139
	140	for (Double_t x = radius+dirstep; dirx < dirr; x += dirstep) {
	141
	142	GetXYZ(xyz0);
	143	Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
bf3b953e	144	if(!Rotate(alpha,kTRUE)) return kFALSE;
83253968	145	GetXYZ(xyz0);
6d256146	146	if (!GetProlongation(x,y,z)) return kFALSE;
83253968	147	xyz1[0] = x * TMath::Cos(alpha) + y * TMath::Sin(alpha);
	148	xyz1[1] = x * TMath::Sin(alpha) - y * TMath::Cos(alpha);
	149	xyz1[2] = z;
	150	Double_t param[7];
	151	AliTracker::MeanMaterialBudget(xyz0,xyz1,param);
	152	if (param[1] <= 0) {
	153	param[1] = 100000000;
	154	}
	155	PropagateTo(x,param[1],param[0]*param[4]);
	156
	157	}
	158
	159	GetXYZ(xyz0);
	160	Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
bf3b953e	161	if(!Rotate(alpha,kTRUE)) return kFALSE;
83253968	162	GetXYZ(xyz0);
6d256146	163	if (!GetProlongation(r,y,z)) return kFALSE;
83253968	164	xyz1[0] = r * TMath::Cos(alpha) + y * TMath::Sin(alpha);
	165	xyz1[1] = r * TMath::Sin(alpha) - y * TMath::Cos(alpha);
	166	xyz1[2] = z;
	167	Double_t param[7];
	168	AliTracker::MeanMaterialBudget(xyz0,xyz1,param);
	169
	170	if (param[1] <= 0) {
	171	param[1] = 100000000;
	172	}
496c71b0	173
496c71b0	174	return PropagateTo(r,param[1],param[0]*param[4]);
83253968	175	}
	176	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	177	Double_t AliHMPIDtrack::GetPredictedChi2(const AliCluster3D *c) const {
	178	//
	179	// Arguments: AliCluster3D
	180	// Returns: Chi2 of track for the cluster
	181	Double_t p[3]={c->GetX(), c->GetY(), c->GetZ()};
	182	Double_t covyz[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
	183	Double_t covxyz[3]={c->GetSigmaX2(), c->GetSigmaXY(), c->GetSigmaXZ()};
	184	return AliExternalTrackParam::GetPredictedChi2(p, covyz, covxyz);
	185	}//GetPredictedChi2()
	186	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	187	Bool_t AliHMPIDtrack::PropagateTo(const AliCluster3D *c) {
	188	//
	189	// Arguments: AliCluster3D
	190	// Returns: kTRUE if the track propagates to the plane of the cluster
	191	Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
	192	Double_t p[3]={c->GetX(), c->GetY(), c->GetZ()};
	193	Double_t covyz[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
	194	Double_t covxyz[3]={c->GetSigmaX2(), c->GetSigmaXY(), c->GetSigmaXZ()};
5b147198	195	Double_t bz=-GetBz();
87a6d94b	196
83253968	197	if(!AliExternalTrackParam::PropagateTo(p, covyz, covxyz, bz)) return kFALSE;
	198	if(IsStartedTimeIntegral())
	199	{
	200	Double_t d = TMath::Sqrt((GetX()-oldX)(GetX()-oldX) + (GetY()-oldY)(GetY()-oldY) + (GetZ()-oldZ)*(GetZ()-oldZ));
	201	if (GetX()<oldX) d=-d;
	202	AddTimeStep(d);
87a6d94b	203	}
83253968	204	return kTRUE;
83253968	205	}//PropagateTo()
97a4d538	206	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
97a4d538	207	Bool_t AliHMPIDtrack::Intersect(Double_t pnt[3], Double_t norm[3]) const {
83253968	208	//+++++++++++++++++++++++++++++++++++++++++
	209	// Origin: K. Shileev (Kirill.Shileev@cern.ch)
	210	// Finds point of intersection (if exists) of the helix with the plane.
	211	// Stores result in fX and fP.
	212	// Arguments: planePoint,planeNorm - the plane defined by any plane's point
	213	// and vector, normal to the plane
	214	// Returns: kTrue if helix intersects the plane, kFALSE otherwise.
	215	//+++++++++++++++++++++++++++++++++++++++++
	216	Double_t x0[3]; GetXYZ(x0); //get track position in MARS
83253968	217
	218	//estimates initial helix length up to plane
	219	Double_t s=(pnt[0]-x0[0])norm[0] + (pnt[1]-x0[1])norm[1] + (pnt[2]-x0[2])*norm[2];
	220	Double_t dist=99999,distPrev=dist;
97a4d538	221	Double_t p[3],x[3];
83253968	222	while(TMath::Abs(dist)>0.00001){
83253968	223	//calculates helix at the distance s from x0 ALONG the helix
97a4d538	224	Propagate(s,x,p);
83253968	225	//distance between current helix position and plane
	226	dist=(x[0]-pnt[0])norm[0]+(x[1]-pnt[1])norm[1]+(x[2]-pnt[2])*norm[2];
	227	if(TMath::Abs(dist) >= TMath::Abs(distPrev)) {return kFALSE;}
	228	distPrev=dist;
	229	s-=dist;
	230	}
	231	//on exit pnt is intersection point,norm is track vector at that point,
	232	//all in MARS
	233	for (Int_t i=0; i<3; i++) {pnt[i]=x[i]; norm[i]=p[i];}
	234	return kTRUE;
	235	}//Intersect()
	236	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
97a4d538	237	void AliHMPIDtrack::Propagate(Double_t len, Double_t x[3],Double_t p[3]) const {
83253968	238	//+++++++++++++++++++++++++++++++++++++++++
	239	// Origin: K. Shileev (Kirill.Shileev@cern.ch)
	240	// Extrapolate track along simple helix in magnetic field
	241	// Arguments: len -distance alogn helix, [cm]
	242	// bz - mag field, [kGaus]
	243	// Returns: x and p contain extrapolated positon and momentum
	244	// The momentum returned for straight-line tracks is meaningless !
	245	//+++++++++++++++++++++++++++++++++++++++++
	246	GetXYZ(x);
97a4d538	247	Double_t bField[3];
97a4d538	248	TGeoGlobalMagField::Instance()->Field(x,bField);
5b147198	249	Double_t bz = -bField[2];
83253968	250	if (OneOverPt() < kAlmost0 \|\| TMath::Abs(bz) < kAlmost0Field ){ //straight-line tracks
	251	Double_t unit[3]; GetDirection(unit);
	252	x[0]+=unit[0]*len;
	253	x[1]+=unit[1]*len;
	254	x[2]+=unit[2]*len;
	255
	256	p[0]=unit[0]/kAlmost0;
	257	p[1]=unit[1]/kAlmost0;
	258	p[2]=unit[2]/kAlmost0;
	259	} else {
	260	GetPxPyPz(p);
	261	Double_t pp=GetP();
	262	Double_t a = -kB2CbzGetSign(); ////////// what is kB2C
	263	Double_t rho = a/pp;
	264	x[0] += p[0]TMath::Sin(rholen)/a - p[1](1-TMath::Cos(rholen))/a;
	265	x[1] += p[1]TMath::Sin(rholen)/a + p[0](1-TMath::Cos(rholen))/a;
	266	x[2] += p[2]*len/pp;
	267	Double_t p0=p[0];
	268	p[0] = p0 TMath::Cos(rholen) - p[1]TMath::Sin(rholen);
	269	p[1] = p[1]TMath::Cos(rholen) + p0 TMath::Sin(rholen);
	270	}
	271	}//Propagate()
	272	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ee2f3539	273	Bool_t AliHMPIDtrack::Update(const AliHMPIDCluster pClu, Double_t /chisq/, Int_t /index*/)
496c71b0	274	{
	275	//
	276	// Arguments: AliCluster3D, chi sq, and clu index
	277	// Returns: kTRUE if the track parameters are successfully updated
	278	Double_t p[2]={pClu->GetY(), pClu->GetZ()};
	279	Double_t cov[3]={pClu->GetSigmaY2(), 0., pClu->GetSigmaZ2()};
	280	if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
	281
	282	/*
	283	AliTracker::FillResiduals(this,p,cov,pClu->GetVolumeId());
	284
	285	Int_t n=GetNumberOfClusters();
	286	fIndex[n]=index;
	287	SetNumberOfClusters(n+1);
	288	SetChi2(GetChi2()+chisq);
	289	*/
	290	return kTRUE;
	291
	292	}//Update()
	293	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++