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

//-----------------------------------------------------------------
//           Implementation of the TPC track class
//
// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
//-----------------------------------------------------------------

#include <iostream.h>

#include "AliCluster.h"
#include "AliTPCtrack.h"
#include "AliTPCcluster.h"
#include "AliTPCClustersRow.h"
#include "AliTPCClustersArray.h"

ClassImp(AliTPCtrack)
//_________________________________________________________________________
AliTPCtrack::AliTPCtrack(UInt_t index, const Double_t xx[5],
const Double_t cc[15], Double_t xref, Double_t alpha) : AliKalmanTrack() {
  //-----------------------------------------------------------------
  // This is the main track constructor.
  //-----------------------------------------------------------------
  fX=xref;
  fAlpha=alpha;
  if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
  if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
  fdEdx=0.;

  fP0=xx[0]; fP1=xx[1]; fP2=xx[2]; fP3=xx[3]; fP4=xx[4];

  fC00=cc[0];
  fC10=cc[1];  fC11=cc[2];
  fC20=cc[3];  fC21=cc[4];  fC22=cc[5];
  fC30=cc[6];  fC31=cc[7];  fC32=cc[8];  fC33=cc[9];
  fC40=cc[10]; fC41=cc[11]; fC42=cc[12]; fC43=cc[13]; fC44=cc[14];

  fIndex[0]=index;
  SetNumberOfClusters(1);
}

//_____________________________________________________________________________
AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) : AliKalmanTrack(t) {
  //-----------------------------------------------------------------
  // This is a track copy constructor.
  //-----------------------------------------------------------------
  fX=t.fX;
  fAlpha=t.fAlpha;
  fdEdx=t.fdEdx;

  fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4;

  fC00=t.fC00;
  fC10=t.fC10;  fC11=t.fC11;
  fC20=t.fC20;  fC21=t.fC21;  fC22=t.fC22;
  fC30=t.fC30;  fC31=t.fC31;  fC32=t.fC32;  fC33=t.fC33;
  fC40=t.fC40;  fC41=t.fC41;  fC42=t.fC42;  fC43=t.fC43;  fC44=t.fC44;

  Int_t n=GetNumberOfClusters();
  for (Int_t i=0; i<n; i++) fIndex[i]=t.fIndex[i];
}

//_____________________________________________________________________________
Int_t AliTPCtrack::Compare(const TObject *o) const {
  //-----------------------------------------------------------------
  // This function compares tracks according to the their curvature
  //-----------------------------------------------------------------
  AliTPCtrack *t=(AliTPCtrack*)o;
  Double_t co=TMath::Abs(t->Get1Pt());
  Double_t c =TMath::Abs(Get1Pt());
  if (c>co) return 1;
  else if (c<co) return -1;
  return 0;
}

//_____________________________________________________________________________
void AliTPCtrack::GetExternalCovariance(Double_t cc[15]) const {
  //-------------------------------------------------------------------------
  // This function returns an external representation of the covriance matrix.
  //   (See comments in AliTPCtrack.h about external track representation)
  //-------------------------------------------------------------------------
  Double_t a=kConversionConstant;

  Double_t c22=fX*fX*fC33-2*fX*fC32+fC22;
  Double_t c42=fX*fC43-fC42;
  Double_t c20=fX*fC30-fC20, c21=fX*fC31-fC21, c32=fX*fC33-fC32;
  
  cc[0 ]=fC00;
  cc[1 ]=fC10;   cc[2 ]=fC11;
  cc[3 ]=c20;    cc[4 ]=c21;    cc[5 ]=c22;
  cc[6 ]=fC40;   cc[7 ]=fC41;   cc[8 ]=c42;   cc[9 ]=fC44; 
  cc[10]=fC30*a; cc[11]=fC31*a; cc[12]=c32*a; cc[13]=fC43*a; cc[14]=fC33*a*a;

}

//_____________________________________________________________________________
Double_t AliTPCtrack::GetPredictedChi2(const AliCluster *c) const 
{
  //-----------------------------------------------------------------
  // This function calculates a predicted chi2 increment.
  //-----------------------------------------------------------------
  Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
  r00+=fC00; r01+=fC10; r11+=fC11;

  Double_t det=r00*r11 - r01*r01;
  if (TMath::Abs(det) < 1.e-10) {
    Int_t n=GetNumberOfClusters();
    if (n>4) cerr<<n<<" AliKalmanTrack warning: Singular matrix !\n";
    return 1e10;
  }
  Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
  
  Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
  
  return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
}

//_____________________________________________________________________________
Int_t AliTPCtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho,Double_t pm)
{
  //-----------------------------------------------------------------
  // This function propagates a track to a reference plane x=xk.
  //-----------------------------------------------------------------
  if (TMath::Abs(fP3*xk - fP2) >= 0.99999) {
    Int_t n=GetNumberOfClusters();
    if (n>4) cerr<<n<<" AliTPCtrack warning: Propagation failed !\n";
    return 0;
  }

  Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fP0, z1=fP1;
  Double_t c1=fP3*x1 - fP2, r1=sqrt(1.- c1*c1);
  Double_t c2=fP3*x2 - fP2, r2=sqrt(1.- c2*c2);
  
  fP0 += dx*(c1+c2)/(r1+r2);
  fP1 += dx*(c1+c2)/(c1*r2 + c2*r1)*fP4;

  //f = F - 1
  Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
  Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
  Double_t f03= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
  Double_t cr=c1*r2+c2*r1;
  Double_t f12=-dx*fP4*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
  Double_t f13=dx*fP4*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
  Double_t f14= dx*cc/cr; 

  //b = C*ft
  Double_t b00=f02*fC20 + f03*fC30, b01=f12*fC20 + f13*fC30 + f14*fC40;
  Double_t b10=f02*fC21 + f03*fC31, b11=f12*fC21 + f13*fC31 + f14*fC41;
  Double_t b20=f02*fC22 + f03*fC32, b21=f12*fC22 + f13*fC32 + f14*fC42;
  Double_t b30=f02*fC32 + f03*fC33, b31=f12*fC32 + f13*fC33 + f14*fC43;
  Double_t b40=f02*fC42 + f03*fC43, b41=f12*fC42 + f13*fC43 + f14*fC44;
  
  //a = f*b = f*C*ft
  Double_t a00=f02*b20+f03*b30,a01=f02*b21+f03*b31,a11=f12*b21+f13*b31+f14*b41;

  //F*C*Ft = C + (a + b + bt)
  fC00 += a00 + 2*b00;
  fC10 += a01 + b01 + b10; 
  fC20 += b20;
  fC30 += b30;
  fC40 += b40;
  fC11 += a11 + 2*b11;
  fC21 += b21; 
  fC31 += b31; 
  fC41 += b41; 

  fX=x2;

  //Multiple scattering******************
  Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fP0)*(y1-fP0)+(z1-fP1)*(z1-fP1));
  Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
  Double_t beta2=p2/(p2 + pm*pm);
  Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
  //Double_t theta2=1.0259e-6*10*10/20/(beta2*p2)*d*rho;

  Double_t ey=fP3*fX - fP2, ez=fP4;
  Double_t xz=fP3*ez, zz1=ez*ez+1, xy=fP2+ey;

  fC33 += xz*xz*theta2;
  fC32 += xz*ez*xy*theta2;
  fC43 += xz*zz1*theta2;
  fC22 += (2*ey*ez*ez*fP2+1-ey*ey+ez*ez+fP2*fP2*ez*ez)*theta2;
  fC42 += ez*zz1*xy*theta2;
  fC44 += zz1*zz1*theta2;

  //Energy losses************************
  Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d*rho;
  if (x1 < x2) dE=-dE;
  cc=fP3;
  fP3*=(1.- sqrt(p2+pm*pm)/p2*dE);
  fP2+=fX*(fP3-cc);

  return 1;
}

//_____________________________________________________________________________
Int_t AliTPCtrack::PropagateToVertex(Double_t x0,Double_t rho,Double_t pm) 
{
  //-----------------------------------------------------------------
  // This function propagates tracks to the "vertex".
  //-----------------------------------------------------------------
  Double_t c=fP3*fX - fP2;
  Double_t tgf=-fP2/(fP3*fP0 + sqrt(1-c*c));
  Double_t snf=tgf/sqrt(1.+ tgf*tgf);
  Double_t xv=(fP2+snf)/fP3;
  return PropagateTo(xv,x0,rho,pm);
}

//_____________________________________________________________________________
Int_t AliTPCtrack::Update(const AliCluster *c, Double_t chisq, UInt_t index) {
  //-----------------------------------------------------------------
  // This function associates a cluster with this track.
  //-----------------------------------------------------------------
  Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
  r00+=fC00; r01+=fC10; r11+=fC11;
  Double_t det=r00*r11 - r01*r01;
  Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;

  Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11;
  Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11;
  Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11;
  Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11;
  Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;

  Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
  Double_t cur=fP3 + k30*dy + k31*dz, eta=fP2 + k20*dy + k21*dz;
  if (TMath::Abs(cur*fX-eta) >= 0.99999) {
    Int_t n=GetNumberOfClusters();
    if (n>4) cerr<<n<<" AliTPCtrack warning: Filtering failed !\n";
    return 0;
  }

  fP0 += k00*dy + k01*dz;
  fP1 += k10*dy + k11*dz;
  fP2  = eta;
  fP3  = cur;
  fP4 += k40*dy + k41*dz;

  Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
  Double_t c12=fC21, c13=fC31, c14=fC41;

  fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11;
  fC20-=k00*c02+k01*c12;   fC30-=k00*c03+k01*c13;
  fC40-=k00*c04+k01*c14; 

  fC11-=k10*c01+k11*fC11;
  fC21-=k10*c02+k11*c12;   fC31-=k10*c03+k11*c13;
  fC41-=k10*c04+k11*c14; 

  fC22-=k20*c02+k21*c12;   fC32-=k20*c03+k21*c13;
  fC42-=k20*c04+k21*c14; 

  fC33-=k30*c03+k31*c13;
  fC43-=k30*c04+k31*c14; 

  fC44-=k40*c04+k41*c14; 

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

  return 1;
}

//_____________________________________________________________________________
Int_t AliTPCtrack::Rotate(Double_t alpha)
{
  //-----------------------------------------------------------------
  // This function rotates this track.
  //-----------------------------------------------------------------
  fAlpha += alpha;
  if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
  if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
  
  Double_t x1=fX, y1=fP0;
  Double_t ca=cos(alpha), sa=sin(alpha);
  Double_t r1=fP3*fX - fP2;
  
  fX = x1*ca + y1*sa;
  fP0=-x1*sa + y1*ca;
  fP2=fP2*ca + (fP3*y1 + sqrt(1.- r1*r1))*sa;
  
  Double_t r2=fP3*fX - fP2;
  if (TMath::Abs(r2) >= 0.99999) {
    Int_t n=GetNumberOfClusters();
    if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !\n";
    return 0;
  }
  
  Double_t y0=fP0 + sqrt(1.- r2*r2)/fP3;
  if ((fP0-y0)*fP3 >= 0.) {
    Int_t n=GetNumberOfClusters();
    if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !!!\n";
    return 0;
  }

  //f = F - 1
  Double_t f00=ca-1,    f23=(y1 - r1*x1/sqrt(1.- r1*r1))*sa, 
           f20=fP3*sa,  f22=(ca + sa*r1/sqrt(1.- r1*r1))-1;

  //b = C*ft
  Double_t b00=fC00*f00, b02=fC00*f20+fC30*f23+fC20*f22;
  Double_t b10=fC10*f00, b12=fC10*f20+fC31*f23+fC21*f22;
  Double_t b20=fC20*f00, b22=fC20*f20+fC32*f23+fC22*f22;
  Double_t b30=fC30*f00, b32=fC30*f20+fC33*f23+fC32*f22;
  Double_t b40=fC40*f00, b42=fC40*f20+fC43*f23+fC42*f22;

  //a = f*b = f*C*ft
  Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f23*b32+f22*b22;

  // *** Double_t dy2=fCyy;

  //F*C*Ft = C + (a + b + bt)
  fC00 += a00 + 2*b00;
  fC10 += b10;
  fC20 += a02+b20+b02;
  fC30 += b30;
  fC40 += b40;
  fC21 += b12;
  fC32 += b32;
  fC22 += a22 + 2*b22;
  fC42 += b42; 

  // *** fCyy+=dy2*sa*sa*r1*r1/(1.- r1*r1);
  // *** fCzz+=d2y*sa*sa*fT*fT/(1.- r1*r1);

  return 1;
}

//_____________________________________________________________________________
void AliTPCtrack::CookLabel(AliTPCClustersArray *ca) {
  //-----------------------------------------------------------------
  // This function cooks the track label. If label<0, this track is fake.
  //-----------------------------------------------------------------
  Int_t n=GetNumberOfClusters();
  Int_t *lb=new Int_t[n];
  Int_t *mx=new Int_t[n];
  AliTPCcluster **clusters=new AliTPCcluster*[n];

  Int_t i;
  Int_t sec,row,ncl;
  for (i=0; i<n; i++) {
     lb[i]=mx[i]=0;
     GetCluster(i,sec,row,ncl);
     AliTPCClustersRow *clrow=ca->GetRow(sec,row);
     clusters[i]=(AliTPCcluster*)(*clrow)[ncl];      
  }
  
  Int_t lab=123456789;
  for (i=0; i<n; i++) {
    AliTPCcluster *c=clusters[i];
    lab=TMath::Abs(c->GetLabel(0));
    Int_t j;
    for (j=0; j<n; j++)
      if (lb[j]==lab || mx[j]==0) break;
    lb[j]=lab;
    (mx[j])++;
  }
  
  Int_t max=0;
  for (i=0; i<n; i++) 
    if (mx[i]>max) {max=mx[i]; lab=lb[i];}
    
  for (i=0; i<n; i++) {
    AliTPCcluster *c=clusters[i];
    if (TMath::Abs(c->GetLabel(1)) == lab ||
        TMath::Abs(c->GetLabel(2)) == lab ) max++;
  }
  
  SetLabel(-lab);
  if (1.-Float_t(max)/n <= 0.10) {
    //Int_t tail=Int_t(0.08*fN);
     Int_t tail=14;
     max=0;
     for (i=1; i<=tail; i++) {
       AliTPCcluster *c=clusters[n-i];
       if (lab == TMath::Abs(c->GetLabel(0)) ||
           lab == TMath::Abs(c->GetLabel(1)) ||
           lab == TMath::Abs(c->GetLabel(2))) max++;
     }
     if (max >= Int_t(0.5*tail)) SetLabel(lab);
  }
/*
if (lab==111)
   for (i=0; i<n; i++) {
     AliTPCcluster *c=clusters[i];
     cerr<<i<<' '<<c->GetLabel(0)<<endl;
   }
*/
  delete[] lb;
  delete[] mx;
  delete[] clusters;
}
Commit	Line	Data
73042f01	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
73042f01	16	//-----------------------------------------------------------------
	17	// Implementation of the TPC track class
	18	//
	19	// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
	20	//-----------------------------------------------------------------
	21
b19a0509	22	#include <iostream.h>
	23
	24	#include "AliCluster.h"
73042f01	25	#include "AliTPCtrack.h"
	26	#include "AliTPCcluster.h"
	27	#include "AliTPCClustersRow.h"
	28	#include "AliTPCClustersArray.h"
	29
	30	ClassImp(AliTPCtrack)
	31	//_________________________________________________________________________
	32	AliTPCtrack::AliTPCtrack(UInt_t index, const Double_t xx[5],
b19a0509	33	const Double_t cc[15], Double_t xref, Double_t alpha) : AliKalmanTrack() {
73042f01	34	//-----------------------------------------------------------------
	35	// This is the main track constructor.
	36	//-----------------------------------------------------------------
73042f01	37	fX=xref;
be9c5115	38	fAlpha=alpha;
	39	if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
	40	if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
	41	fdEdx=0.;
73042f01	42
b19a0509	43	fP0=xx[0]; fP1=xx[1]; fP2=xx[2]; fP3=xx[3]; fP4=xx[4];
73042f01	44
b19a0509	45	fC00=cc[0];
	46	fC10=cc[1]; fC11=cc[2];
	47	fC20=cc[3]; fC21=cc[4]; fC22=cc[5];
	48	fC30=cc[6]; fC31=cc[7]; fC32=cc[8]; fC33=cc[9];
	49	fC40=cc[10]; fC41=cc[11]; fC42=cc[12]; fC43=cc[13]; fC44=cc[14];
73042f01	50
be9c5115	51	fIndex[0]=index;
be9c5115	52	SetNumberOfClusters(1);
73042f01	53	}
	54
	55	//_____________________________________________________________________________
b19a0509	56	AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) : AliKalmanTrack(t) {
73042f01	57	//-----------------------------------------------------------------
	58	// This is a track copy constructor.
	59	//-----------------------------------------------------------------
be9c5115	60	fX=t.fX;
be9c5115	61	fAlpha=t.fAlpha;
73042f01	62	fdEdx=t.fdEdx;
73042f01	63
be9c5115	64	fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4;
	65
	66	fC00=t.fC00;
	67	fC10=t.fC10; fC11=t.fC11;
	68	fC20=t.fC20; fC21=t.fC21; fC22=t.fC22;
	69	fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33;
	70	fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44;
	71
	72	Int_t n=GetNumberOfClusters();
	73	for (Int_t i=0; i<n; i++) fIndex[i]=t.fIndex[i];
	74	}
	75
	76	//_____________________________________________________________________________
	77	Int_t AliTPCtrack::Compare(const TObject *o) const {
	78	//-----------------------------------------------------------------
	79	// This function compares tracks according to the their curvature
	80	//-----------------------------------------------------------------
	81	AliTPCtrack t=(AliTPCtrack)o;
	82	Double_t co=TMath::Abs(t->Get1Pt());
	83	Double_t c =TMath::Abs(Get1Pt());
	84	if (c>co) return 1;
	85	else if (c<co) return -1;
	86	return 0;
	87	}
	88
	89	//_____________________________________________________________________________
	90	void AliTPCtrack::GetExternalCovariance(Double_t cc[15]) const {
	91	//-------------------------------------------------------------------------
	92	// This function returns an external representation of the covriance matrix.
	93	// (See comments in AliTPCtrack.h about external track representation)
	94	//-------------------------------------------------------------------------
	95	Double_t a=kConversionConstant;
	96
	97	Double_t c22=fXfXfC33-2fXfC32+fC22;
	98	Double_t c42=fX*fC43-fC42;
	99	Double_t c20=fXfC30-fC20, c21=fXfC31-fC21, c32=fX*fC33-fC32;
	100
	101	cc[0 ]=fC00;
	102	cc[1 ]=fC10; cc[2 ]=fC11;
	103	cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
	104	cc[6 ]=fC40; cc[7 ]=fC41; cc[8 ]=c42; cc[9 ]=fC44;
	105	cc[10]=fC30a; cc[11]=fC31a; cc[12]=c32a; cc[13]=fC43a; cc[14]=fC33aa;
	106
	107	}
	108
	109	//_____________________________________________________________________________
	110	Double_t AliTPCtrack::GetPredictedChi2(const AliCluster *c) const
	111	{
	112	//-----------------------------------------------------------------
	113	// This function calculates a predicted chi2 increment.
	114	//-----------------------------------------------------------------
	115	Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
	116	r00+=fC00; r01+=fC10; r11+=fC11;
	117
	118	Double_t det=r00r11 - r01r01;
	119	if (TMath::Abs(det) < 1.e-10) {
	120	Int_t n=GetNumberOfClusters();
	121	if (n>4) cerr<<n<<" AliKalmanTrack warning: Singular matrix !\n";
	122	return 1e10;
	123	}
	124	Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
	125
	126	Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
	127
128	return (dyr00dy + 2r01dydz + dzr11*dz)/det;
73042f01	129	}
	130
	131	//_____________________________________________________________________________
	132	Int_t AliTPCtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho,Double_t pm)
	133	{
	134	//-----------------------------------------------------------------
	135	// This function propagates a track to a reference plane x=xk.
	136	//-----------------------------------------------------------------
b19a0509	137	if (TMath::Abs(fP3*xk - fP2) >= 0.99999) {
be9c5115	138	Int_t n=GetNumberOfClusters();
be9c5115	139	if (n>4) cerr<<n<<" AliTPCtrack warning: Propagation failed !\n";
73042f01	140	return 0;
	141	}
	142
b19a0509	143	Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fP0, z1=fP1;
	144	Double_t c1=fP3x1 - fP2, r1=sqrt(1.- c1c1);
	145	Double_t c2=fP3x2 - fP2, r2=sqrt(1.- c2c2);
73042f01	146
b19a0509	147	fP0 += dx*(c1+c2)/(r1+r2);
b19a0509	148	fP1 += dx(c1+c2)/(c1r2 + c2r1)fP4;
73042f01	149
	150	//f = F - 1
	151	Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
b19a0509	152	Double_t f02=-dx(2rr + cc(c1/r1 + c2/r2))/(rrrr);
b19a0509	153	Double_t f03= dx(rrxx + cc(c1x1/r1+c2x2/r2))/(rrrr);
73042f01	154	Double_t cr=c1r2+c2r1;
b19a0509	155	Double_t f12=-dxfP4(2cr + cc(c2c1/r1-r1 + c1c2/r2-r2))/(cr*cr);
b19a0509	156	Double_t f13=dxfP4(crxx-cc(r1x2-c2c1x1/r1+r2x1-c1c2x2/r2))/(cr*cr);
73042f01	157	Double_t f14= dx*cc/cr;
	158
	159	//b = C*ft
b19a0509	160	Double_t b00=f02fC20 + f03fC30, b01=f12fC20 + f13fC30 + f14*fC40;
	161	Double_t b10=f02fC21 + f03fC31, b11=f12fC21 + f13fC31 + f14*fC41;
	162	Double_t b20=f02fC22 + f03fC32, b21=f12fC22 + f13fC32 + f14*fC42;
	163	Double_t b30=f02fC32 + f03fC33, b31=f12fC32 + f13fC33 + f14*fC43;
	164	Double_t b40=f02fC42 + f03fC43, b41=f12fC42 + f13fC43 + f14*fC44;
73042f01	165
	166	//a = fb = fC*ft
	167	Double_t a00=f02b20+f03b30,a01=f02b21+f03b31,a11=f12b21+f13b31+f14*b41;
	168
	169	//FCFt = C + (a + b + bt)
b19a0509	170	fC00 += a00 + 2*b00;
	171	fC10 += a01 + b01 + b10;
	172	fC20 += b20;
	173	fC30 += b30;
	174	fC40 += b40;
	175	fC11 += a11 + 2*b11;
	176	fC21 += b21;
	177	fC31 += b31;
	178	fC41 += b41;
73042f01	179
	180	fX=x2;
	181
	182	//Multiple scattering******************
b19a0509	183	Double_t d=sqrt((x1-fX)(x1-fX)+(y1-fP0)(y1-fP0)+(z1-fP1)*(z1-fP1));
be9c5115	184	Double_t p2=(1.+ GetTgl()GetTgl())/(Get1Pt()Get1Pt());
73042f01	185	Double_t beta2=p2/(p2 + pm*pm);
be9c5115	186	Double_t theta2=14.114.1/(beta2p21e6)d/x0*rho;
b19a0509	187	//Double_t theta2=1.0259e-61010/20/(beta2p2)d*rho;
73042f01	188
b19a0509	189	Double_t ey=fP3*fX - fP2, ez=fP4;
b19a0509	190	Double_t xz=fP3ez, zz1=ezez+1, xy=fP2+ey;
73042f01	191
b19a0509	192	fC33 += xzxztheta2;
	193	fC32 += xzezxy*theta2;
	194	fC43 += xzzz1theta2;
	195	fC22 += (2eyezezfP2+1-eyey+ezez+fP2fP2ezez)theta2;
	196	fC42 += ezzz1xy*theta2;
	197	fC44 += zz1zz1theta2;
73042f01	198
	199	//Energy losses************************
	200	Double_t dE=0.153e-3/beta2(log(5940beta2/(1-beta2)) - beta2)drho;
	201	if (x1 < x2) dE=-dE;
b19a0509	202	cc=fP3;
	203	fP3=(1.- sqrt(p2+pmpm)/p2*dE);
	204	fP2+=fX*(fP3-cc);
73042f01	205
	206	return 1;
	207	}
	208
	209	//_____________________________________________________________________________
b19a0509	210	Int_t AliTPCtrack::PropagateToVertex(Double_t x0,Double_t rho,Double_t pm)
73042f01	211	{
	212	//-----------------------------------------------------------------
	213	// This function propagates tracks to the "vertex".
	214	//-----------------------------------------------------------------
b19a0509	215	Double_t c=fP3*fX - fP2;
b19a0509	216	Double_t tgf=-fP2/(fP3fP0 + sqrt(1-cc));
73042f01	217	Double_t snf=tgf/sqrt(1.+ tgf*tgf);
b19a0509	218	Double_t xv=(fP2+snf)/fP3;
b19a0509	219	return PropagateTo(xv,x0,rho,pm);
73042f01	220	}
	221
	222	//_____________________________________________________________________________
be9c5115	223	Int_t AliTPCtrack::Update(const AliCluster *c, Double_t chisq, UInt_t index) {
73042f01	224	//-----------------------------------------------------------------
	225	// This function associates a cluster with this track.
	226	//-----------------------------------------------------------------
	227	Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
b19a0509	228	r00+=fC00; r01+=fC10; r11+=fC11;
73042f01	229	Double_t det=r00r11 - r01r01;
	230	Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
	231
b19a0509	232	Double_t k00=fC00r00+fC10r01, k01=fC00r01+fC10r11;
	233	Double_t k10=fC10r00+fC11r01, k11=fC10r01+fC11r11;
	234	Double_t k20=fC20r00+fC21r01, k21=fC20r01+fC21r11;
	235	Double_t k30=fC30r00+fC31r01, k31=fC30r01+fC31r11;
	236	Double_t k40=fC40r00+fC41r01, k41=fC40r01+fC41r11;
73042f01	237
b19a0509	238	Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
b19a0509	239	Double_t cur=fP3 + k30dy + k31dz, eta=fP2 + k20dy + k21dz;
73042f01	240	if (TMath::Abs(cur*fX-eta) >= 0.99999) {
be9c5115	241	Int_t n=GetNumberOfClusters();
	242	if (n>4) cerr<<n<<" AliTPCtrack warning: Filtering failed !\n";
	243	return 0;
73042f01	244	}
73042f01	245
b19a0509	246	fP0 += k00dy + k01dz;
	247	fP1 += k10dy + k11dz;
	248	fP2 = eta;
	249	fP3 = cur;
	250	fP4 += k40dy + k41dz;
73042f01	251
b19a0509	252	Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
b19a0509	253	Double_t c12=fC21, c13=fC31, c14=fC41;
73042f01	254
b19a0509	255	fC00-=k00fC00+k01fC10; fC10-=k00c01+k01fC11;
	256	fC20-=k00c02+k01c12; fC30-=k00c03+k01c13;
	257	fC40-=k00c04+k01c14;
73042f01	258
b19a0509	259	fC11-=k10c01+k11fC11;
	260	fC21-=k10c02+k11c12; fC31-=k10c03+k11c13;
	261	fC41-=k10c04+k11c14;
73042f01	262
b19a0509	263	fC22-=k20c02+k21c12; fC32-=k20c03+k21c13;
b19a0509	264	fC42-=k20c04+k21c14;
73042f01	265
b19a0509	266	fC33-=k30c03+k31c13;
b19a0509	267	fC43-=k30c04+k31c14;
73042f01	268
b19a0509	269	fC44-=k40c04+k41c14;
73042f01	270
be9c5115	271	Int_t n=GetNumberOfClusters();
	272	fIndex[n]=index;
	273	SetNumberOfClusters(n+1);
	274	SetChi2(GetChi2()+chisq);
	275
	276	return 1;
73042f01	277	}
	278
	279	//_____________________________________________________________________________
	280	Int_t AliTPCtrack::Rotate(Double_t alpha)
	281	{
	282	//-----------------------------------------------------------------
	283	// This function rotates this track.
	284	//-----------------------------------------------------------------
	285	fAlpha += alpha;
be9c5115	286	if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
be9c5115	287	if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
73042f01	288
b19a0509	289	Double_t x1=fX, y1=fP0;
73042f01	290	Double_t ca=cos(alpha), sa=sin(alpha);
b19a0509	291	Double_t r1=fP3*fX - fP2;
73042f01	292
73042f01	293	fX = x1ca + y1sa;
b19a0509	294	fP0=-x1sa + y1ca;
b19a0509	295	fP2=fP2ca + (fP3y1 + sqrt(1.- r1r1))sa;
73042f01	296
b19a0509	297	Double_t r2=fP3*fX - fP2;
73042f01	298	if (TMath::Abs(r2) >= 0.99999) {
be9c5115	299	Int_t n=GetNumberOfClusters();
be9c5115	300	if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !\n";
73042f01	301	return 0;
	302	}
	303
b19a0509	304	Double_t y0=fP0 + sqrt(1.- r2*r2)/fP3;
b19a0509	305	if ((fP0-y0)*fP3 >= 0.) {
be9c5115	306	Int_t n=GetNumberOfClusters();
be9c5115	307	if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !!!\n";
73042f01	308	return 0;
	309	}
	310
	311	//f = F - 1
b19a0509	312	Double_t f00=ca-1, f23=(y1 - r1x1/sqrt(1.- r1r1))*sa,
b19a0509	313	f20=fP3sa, f22=(ca + sar1/sqrt(1.- r1*r1))-1;
73042f01	314
73042f01	315	//b = C*ft
b19a0509	316	Double_t b00=fC00f00, b02=fC00f20+fC30f23+fC20f22;
	317	Double_t b10=fC10f00, b12=fC10f20+fC31f23+fC21f22;
	318	Double_t b20=fC20f00, b22=fC20f20+fC32f23+fC22f22;
	319	Double_t b30=fC30f00, b32=fC30f20+fC33f23+fC32f22;
	320	Double_t b40=fC40f00, b42=fC40f20+fC43f23+fC42f22;
73042f01	321
73042f01	322	//a = fb = fC*ft
b19a0509	323	Double_t a00=f00b00, a02=f00b02, a22=f20b02+f23b32+f22*b22;
73042f01	324
	325	// *** Double_t dy2=fCyy;
	326
	327	//FCFt = C + (a + b + bt)
b19a0509	328	fC00 += a00 + 2*b00;
	329	fC10 += b10;
	330	fC20 += a02+b20+b02;
	331	fC30 += b30;
	332	fC40 += b40;
	333	fC21 += b12;
	334	fC32 += b32;
	335	fC22 += a22 + 2*b22;
	336	fC42 += b42;
73042f01	337
	338	// *** fCyy+=dy2sasar1r1/(1.- r1*r1);
	339	// *** fCzz+=d2ysasafTfT/(1.- r1*r1);
	340
	341	return 1;
	342	}
	343
73042f01	344	//_____________________________________________________________________________
	345	void AliTPCtrack::CookLabel(AliTPCClustersArray *ca) {
	346	//-----------------------------------------------------------------
	347	// This function cooks the track label. If label<0, this track is fake.
	348	//-----------------------------------------------------------------
be9c5115	349	Int_t n=GetNumberOfClusters();
	350	Int_t *lb=new Int_t[n];
	351	Int_t *mx=new Int_t[n];
	352	AliTPCcluster *clusters=new AliTPCcluster[n];
73042f01	353
	354	Int_t i;
	355	Int_t sec,row,ncl;
be9c5115	356	for (i=0; i<n; i++) {
73042f01	357	lb[i]=mx[i]=0;
	358	GetCluster(i,sec,row,ncl);
	359	AliTPCClustersRow *clrow=ca->GetRow(sec,row);
	360	clusters[i]=(AliTPCcluster)(clrow)[ncl];
	361	}
	362
	363	Int_t lab=123456789;
be9c5115	364	for (i=0; i<n; i++) {
73042f01	365	AliTPCcluster *c=clusters[i];
	366	lab=TMath::Abs(c->GetLabel(0));
	367	Int_t j;
be9c5115	368	for (j=0; j<n; j++)
73042f01	369	if (lb[j]==lab \|\| mx[j]==0) break;
	370	lb[j]=lab;
	371	(mx[j])++;
	372	}
	373
	374	Int_t max=0;
be9c5115	375	for (i=0; i<n; i++)
73042f01	376	if (mx[i]>max) {max=mx[i]; lab=lb[i];}
73042f01	377
be9c5115	378	for (i=0; i<n; i++) {
73042f01	379	AliTPCcluster *c=clusters[i];
	380	if (TMath::Abs(c->GetLabel(1)) == lab \|\|
	381	TMath::Abs(c->GetLabel(2)) == lab ) max++;
	382	}
	383
	384	SetLabel(-lab);
be9c5115	385	if (1.-Float_t(max)/n <= 0.10) {
73042f01	386	//Int_t tail=Int_t(0.08*fN);
	387	Int_t tail=14;
	388	max=0;
	389	for (i=1; i<=tail; i++) {
be9c5115	390	AliTPCcluster *c=clusters[n-i];
73042f01	391	if (lab == TMath::Abs(c->GetLabel(0)) \|\|
	392	lab == TMath::Abs(c->GetLabel(1)) \|\|
	393	lab == TMath::Abs(c->GetLabel(2))) max++;
	394	}
	395	if (max >= Int_t(0.5*tail)) SetLabel(lab);
	396	}
be9c5115	397	/*
	398	if (lab==111)
	399	for (i=0; i<n; i++) {
	400	AliTPCcluster *c=clusters[i];
	401	cerr<<i<<' '<<c->GetLabel(0)<<endl;
	402	}
	403	*/
73042f01	404	delete[] lb;
	405	delete[] mx;
	406	delete[] clusters;
	407	}