[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.
  //-----------------------------------------------------------------
  fdEdx=0.;

  fAlpha=alpha;
  fX=xref;

  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[fN++]=index;
}

//_____________________________________________________________________________
AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) : AliKalmanTrack(t) {
  //-----------------------------------------------------------------
  // This is a track copy constructor.
  //-----------------------------------------------------------------
  for (Int_t i=0; i<fN; i++) fIndex[i]=t.fIndex[i];

  fdEdx=t.fdEdx;

  fAlpha=t.fAlpha;
  fX=t.fX;
}

//_____________________________________________________________________________
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) {
    if (fN>4) cerr<<fN<<" 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=GetP()*GetP();
  Double_t beta2=p2/(p2 + pm*pm);
  Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho/2.;
  //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);
}

//_____________________________________________________________________________
void 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) {
    if (fN>4) cerr<<fN<<" AliTPCtrack warning: Filtering failed !\n";
    return;
  }

  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; 

  fIndex[fN++]=index;
  fChi2 += chisq;
}

//_____________________________________________________________________________
Int_t AliTPCtrack::Rotate(Double_t alpha)
{
  //-----------------------------------------------------------------
  // This function rotates this track.
  //-----------------------------------------------------------------
  fAlpha += alpha;
  
  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) {
    if (fN>4) cerr<<fN<<" AliTPCtrack warning: Rotation failed !\n";
    return 0;
  }
  
  Double_t y0=fP0 + sqrt(1.- r2*r2)/fP3;
  if ((fP0-y0)*fP3 >= 0.) {
    if (fN>4) cerr<<fN<<" 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::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const 
{
  //-----------------------------------------------------------------
  // This function returns reconstructed track momentum in the global system.
  //-----------------------------------------------------------------
  Double_t pt=TMath::Abs(GetPt()); // GeV/c
  Double_t r=fP3*fX-fP2;
  Double_t y0=fP0 + sqrt(1.- r*r)/fP3;
  px=-pt*(fP0-y0)*fP3;    //cos(phi);
  py=-pt*(fP2-fX *fP3);   //sin(phi);
  pz=pt*fP4;
  Double_t tmp=px*TMath::Cos(fAlpha) - py*TMath::Sin(fAlpha);
  py=px*TMath::Sin(fAlpha) + py*TMath::Cos(fAlpha);
  px=tmp;  
}

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

  Int_t i;
  Int_t sec,row,ncl;
  for (i=0; i<fN; 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<fN; i++) {
    AliTPCcluster *c=clusters[i];
    lab=TMath::Abs(c->GetLabel(0));
    Int_t j;
    for (j=0; j<fN; j++)
      if (lb[j]==lab || mx[j]==0) break;
    lb[j]=lab;
    (mx[j])++;
  }
  
  Int_t max=0;
  for (i=0; i<fN; i++) 
    if (mx[i]>max) {max=mx[i]; lab=lb[i];}
    
  for (i=0; i<fN; 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)/fN <= 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[fN-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);
  }

  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	fdEdx=0.;
	38
	39	fAlpha=alpha;
	40	fX=xref;
	41
b19a0509	42	fP0=xx[0]; fP1=xx[1]; fP2=xx[2]; fP3=xx[3]; fP4=xx[4];
73042f01	43
b19a0509	44	fC00=cc[0];
	45	fC10=cc[1]; fC11=cc[2];
	46	fC20=cc[3]; fC21=cc[4]; fC22=cc[5];
	47	fC30=cc[6]; fC31=cc[7]; fC32=cc[8]; fC33=cc[9];
	48	fC40=cc[10]; fC41=cc[11]; fC42=cc[12]; fC43=cc[13]; fC44=cc[14];
73042f01	49
73042f01	50	fIndex[fN++]=index;
	51	}
	52
	53	//_____________________________________________________________________________
b19a0509	54	AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) : AliKalmanTrack(t) {
73042f01	55	//-----------------------------------------------------------------
	56	// This is a track copy constructor.
	57	//-----------------------------------------------------------------
b19a0509	58	for (Int_t i=0; i<fN; i++) fIndex[i]=t.fIndex[i];
b19a0509	59
73042f01	60	fdEdx=t.fdEdx;
	61
	62	fAlpha=t.fAlpha;
	63	fX=t.fX;
73042f01	64	}
	65
	66	//_____________________________________________________________________________
	67	Int_t AliTPCtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho,Double_t pm)
	68	{
	69	//-----------------------------------------------------------------
	70	// This function propagates a track to a reference plane x=xk.
	71	//-----------------------------------------------------------------
b19a0509	72	if (TMath::Abs(fP3*xk - fP2) >= 0.99999) {
73042f01	73	if (fN>4) cerr<<fN<<" AliTPCtrack warning: Propagation failed !\n";
	74	return 0;
	75	}
	76
b19a0509	77	Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fP0, z1=fP1;
	78	Double_t c1=fP3x1 - fP2, r1=sqrt(1.- c1c1);
	79	Double_t c2=fP3x2 - fP2, r2=sqrt(1.- c2c2);
73042f01	80
b19a0509	81	fP0 += dx*(c1+c2)/(r1+r2);
b19a0509	82	fP1 += dx(c1+c2)/(c1r2 + c2r1)fP4;
73042f01	83
	84	//f = F - 1
	85	Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
b19a0509	86	Double_t f02=-dx(2rr + cc(c1/r1 + c2/r2))/(rrrr);
b19a0509	87	Double_t f03= dx(rrxx + cc(c1x1/r1+c2x2/r2))/(rrrr);
73042f01	88	Double_t cr=c1r2+c2r1;
b19a0509	89	Double_t f12=-dxfP4(2cr + cc(c2c1/r1-r1 + c1c2/r2-r2))/(cr*cr);
b19a0509	90	Double_t f13=dxfP4(crxx-cc(r1x2-c2c1x1/r1+r2x1-c1c2x2/r2))/(cr*cr);
73042f01	91	Double_t f14= dx*cc/cr;
	92
	93	//b = C*ft
b19a0509	94	Double_t b00=f02fC20 + f03fC30, b01=f12fC20 + f13fC30 + f14*fC40;
	95	Double_t b10=f02fC21 + f03fC31, b11=f12fC21 + f13fC31 + f14*fC41;
	96	Double_t b20=f02fC22 + f03fC32, b21=f12fC22 + f13fC32 + f14*fC42;
	97	Double_t b30=f02fC32 + f03fC33, b31=f12fC32 + f13fC33 + f14*fC43;
	98	Double_t b40=f02fC42 + f03fC43, b41=f12fC42 + f13fC43 + f14*fC44;
73042f01	99
	100	//a = fb = fC*ft
	101	Double_t a00=f02b20+f03b30,a01=f02b21+f03b31,a11=f12b21+f13b31+f14*b41;
	102
	103	//FCFt = C + (a + b + bt)
b19a0509	104	fC00 += a00 + 2*b00;
	105	fC10 += a01 + b01 + b10;
	106	fC20 += b20;
	107	fC30 += b30;
	108	fC40 += b40;
	109	fC11 += a11 + 2*b11;
	110	fC21 += b21;
	111	fC31 += b31;
	112	fC41 += b41;
73042f01	113
	114	fX=x2;
	115
	116	//Multiple scattering******************
b19a0509	117	Double_t d=sqrt((x1-fX)(x1-fX)+(y1-fP0)(y1-fP0)+(z1-fP1)*(z1-fP1));
b19a0509	118	Double_t p2=GetP()*GetP();
73042f01	119	Double_t beta2=p2/(p2 + pm*pm);
b19a0509	120	Double_t theta2=14.114.1/(beta2p21e6)d/x0*rho/2.;
b19a0509	121	//Double_t theta2=1.0259e-61010/20/(beta2p2)d*rho;
73042f01	122
b19a0509	123	Double_t ey=fP3*fX - fP2, ez=fP4;
b19a0509	124	Double_t xz=fP3ez, zz1=ezez+1, xy=fP2+ey;
73042f01	125
b19a0509	126	fC33 += xzxztheta2;
	127	fC32 += xzezxy*theta2;
	128	fC43 += xzzz1theta2;
	129	fC22 += (2eyezezfP2+1-eyey+ezez+fP2fP2ezez)theta2;
	130	fC42 += ezzz1xy*theta2;
	131	fC44 += zz1zz1theta2;
73042f01	132
	133	//Energy losses************************
	134	Double_t dE=0.153e-3/beta2(log(5940beta2/(1-beta2)) - beta2)drho;
	135	if (x1 < x2) dE=-dE;
b19a0509	136	cc=fP3;
	137	fP3=(1.- sqrt(p2+pmpm)/p2*dE);
	138	fP2+=fX*(fP3-cc);
73042f01	139
	140	return 1;
	141	}
	142
	143	//_____________________________________________________________________________
b19a0509	144	Int_t AliTPCtrack::PropagateToVertex(Double_t x0,Double_t rho,Double_t pm)
73042f01	145	{
	146	//-----------------------------------------------------------------
	147	// This function propagates tracks to the "vertex".
	148	//-----------------------------------------------------------------
b19a0509	149	Double_t c=fP3*fX - fP2;
b19a0509	150	Double_t tgf=-fP2/(fP3fP0 + sqrt(1-cc));
73042f01	151	Double_t snf=tgf/sqrt(1.+ tgf*tgf);
b19a0509	152	Double_t xv=(fP2+snf)/fP3;
b19a0509	153	return PropagateTo(xv,x0,rho,pm);
73042f01	154	}
	155
	156	//_____________________________________________________________________________
b19a0509	157	void AliTPCtrack::Update(const AliCluster *c, Double_t chisq, UInt_t index)
73042f01	158	{
	159	//-----------------------------------------------------------------
	160	// This function associates a cluster with this track.
	161	//-----------------------------------------------------------------
	162	Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
b19a0509	163	r00+=fC00; r01+=fC10; r11+=fC11;
73042f01	164	Double_t det=r00r11 - r01r01;
	165	Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
	166
b19a0509	167	Double_t k00=fC00r00+fC10r01, k01=fC00r01+fC10r11;
	168	Double_t k10=fC10r00+fC11r01, k11=fC10r01+fC11r11;
	169	Double_t k20=fC20r00+fC21r01, k21=fC20r01+fC21r11;
	170	Double_t k30=fC30r00+fC31r01, k31=fC30r01+fC31r11;
	171	Double_t k40=fC40r00+fC41r01, k41=fC40r01+fC41r11;
73042f01	172
b19a0509	173	Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
b19a0509	174	Double_t cur=fP3 + k30dy + k31dz, eta=fP2 + k20dy + k21dz;
73042f01	175	if (TMath::Abs(cur*fX-eta) >= 0.99999) {
	176	if (fN>4) cerr<<fN<<" AliTPCtrack warning: Filtering failed !\n";
	177	return;
	178	}
	179
b19a0509	180	fP0 += k00dy + k01dz;
	181	fP1 += k10dy + k11dz;
	182	fP2 = eta;
	183	fP3 = cur;
	184	fP4 += k40dy + k41dz;
73042f01	185
b19a0509	186	Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
b19a0509	187	Double_t c12=fC21, c13=fC31, c14=fC41;
73042f01	188
b19a0509	189	fC00-=k00fC00+k01fC10; fC10-=k00c01+k01fC11;
	190	fC20-=k00c02+k01c12; fC30-=k00c03+k01c13;
	191	fC40-=k00c04+k01c14;
73042f01	192
b19a0509	193	fC11-=k10c01+k11fC11;
	194	fC21-=k10c02+k11c12; fC31-=k10c03+k11c13;
	195	fC41-=k10c04+k11c14;
73042f01	196
b19a0509	197	fC22-=k20c02+k21c12; fC32-=k20c03+k21c13;
b19a0509	198	fC42-=k20c04+k21c14;
73042f01	199
b19a0509	200	fC33-=k30c03+k31c13;
b19a0509	201	fC43-=k30c04+k31c14;
73042f01	202
b19a0509	203	fC44-=k40c04+k41c14;
73042f01	204
	205	fIndex[fN++]=index;
	206	fChi2 += chisq;
	207	}
	208
	209	//_____________________________________________________________________________
	210	Int_t AliTPCtrack::Rotate(Double_t alpha)
	211	{
	212	//-----------------------------------------------------------------
	213	// This function rotates this track.
	214	//-----------------------------------------------------------------
	215	fAlpha += alpha;
	216
b19a0509	217	Double_t x1=fX, y1=fP0;
73042f01	218	Double_t ca=cos(alpha), sa=sin(alpha);
b19a0509	219	Double_t r1=fP3*fX - fP2;
73042f01	220
73042f01	221	fX = x1ca + y1sa;
b19a0509	222	fP0=-x1sa + y1ca;
b19a0509	223	fP2=fP2ca + (fP3y1 + sqrt(1.- r1r1))sa;
73042f01	224
b19a0509	225	Double_t r2=fP3*fX - fP2;
73042f01	226	if (TMath::Abs(r2) >= 0.99999) {
	227	if (fN>4) cerr<<fN<<" AliTPCtrack warning: Rotation failed !\n";
	228	return 0;
	229	}
	230
b19a0509	231	Double_t y0=fP0 + sqrt(1.- r2*r2)/fP3;
b19a0509	232	if ((fP0-y0)*fP3 >= 0.) {
73042f01	233	if (fN>4) cerr<<fN<<" AliTPCtrack warning: Rotation failed !!!\n";
	234	return 0;
	235	}
	236
	237	//f = F - 1
b19a0509	238	Double_t f00=ca-1, f23=(y1 - r1x1/sqrt(1.- r1r1))*sa,
b19a0509	239	f20=fP3sa, f22=(ca + sar1/sqrt(1.- r1*r1))-1;
73042f01	240
73042f01	241	//b = C*ft
b19a0509	242	Double_t b00=fC00f00, b02=fC00f20+fC30f23+fC20f22;
	243	Double_t b10=fC10f00, b12=fC10f20+fC31f23+fC21f22;
	244	Double_t b20=fC20f00, b22=fC20f20+fC32f23+fC22f22;
	245	Double_t b30=fC30f00, b32=fC30f20+fC33f23+fC32f22;
	246	Double_t b40=fC40f00, b42=fC40f20+fC43f23+fC42f22;
73042f01	247
73042f01	248	//a = fb = fC*ft
b19a0509	249	Double_t a00=f00b00, a02=f00b02, a22=f20b02+f23b32+f22*b22;
73042f01	250
	251	// *** Double_t dy2=fCyy;
	252
	253	//FCFt = C + (a + b + bt)
b19a0509	254	fC00 += a00 + 2*b00;
	255	fC10 += b10;
	256	fC20 += a02+b20+b02;
	257	fC30 += b30;
	258	fC40 += b40;
	259	fC21 += b12;
	260	fC32 += b32;
	261	fC22 += a22 + 2*b22;
	262	fC42 += b42;
73042f01	263
	264	// *** fCyy+=dy2sasar1r1/(1.- r1*r1);
	265	// *** fCzz+=d2ysasafTfT/(1.- r1*r1);
	266
	267	return 1;
	268	}
	269
73042f01	270	//_____________________________________________________________________________
	271	void AliTPCtrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const
	272	{
	273	//-----------------------------------------------------------------
	274	// This function returns reconstructed track momentum in the global system.
	275	//-----------------------------------------------------------------
	276	Double_t pt=TMath::Abs(GetPt()); // GeV/c
b19a0509	277	Double_t r=fP3*fX-fP2;
	278	Double_t y0=fP0 + sqrt(1.- r*r)/fP3;
	279	px=-pt(fP0-y0)fP3; //cos(phi);
	280	py=-pt(fP2-fX fP3); //sin(phi);
	281	pz=pt*fP4;
73042f01	282	Double_t tmp=pxTMath::Cos(fAlpha) - pyTMath::Sin(fAlpha);
	283	py=pxTMath::Sin(fAlpha) + pyTMath::Cos(fAlpha);
	284	px=tmp;
	285	}
	286
	287	//_____________________________________________________________________________
	288	void AliTPCtrack::CookLabel(AliTPCClustersArray *ca) {
	289	//-----------------------------------------------------------------
	290	// This function cooks the track label. If label<0, this track is fake.
	291	//-----------------------------------------------------------------
	292	Int_t *lb=new Int_t[fN];
	293	Int_t *mx=new Int_t[fN];
	294	AliTPCcluster *clusters=new AliTPCcluster[fN];
	295
	296	Int_t i;
	297	Int_t sec,row,ncl;
	298	for (i=0; i<fN; i++) {
	299	lb[i]=mx[i]=0;
	300	GetCluster(i,sec,row,ncl);
	301	AliTPCClustersRow *clrow=ca->GetRow(sec,row);
	302	clusters[i]=(AliTPCcluster)(clrow)[ncl];
	303	}
	304
	305	Int_t lab=123456789;
	306	for (i=0; i<fN; i++) {
	307	AliTPCcluster *c=clusters[i];
	308	lab=TMath::Abs(c->GetLabel(0));
	309	Int_t j;
	310	for (j=0; j<fN; j++)
	311	if (lb[j]==lab \|\| mx[j]==0) break;
	312	lb[j]=lab;
	313	(mx[j])++;
	314	}
	315
	316	Int_t max=0;
	317	for (i=0; i<fN; i++)
	318	if (mx[i]>max) {max=mx[i]; lab=lb[i];}
	319
	320	for (i=0; i<fN; i++) {
	321	AliTPCcluster *c=clusters[i];
	322	if (TMath::Abs(c->GetLabel(1)) == lab \|\|
	323	TMath::Abs(c->GetLabel(2)) == lab ) max++;
	324	}
	325
	326	SetLabel(-lab);
	327	if (1.-Float_t(max)/fN <= 0.10) {
	328	//Int_t tail=Int_t(0.08*fN);
	329	Int_t tail=14;
	330	max=0;
	331	for (i=1; i<=tail; i++) {
	332	AliTPCcluster *c=clusters[fN-i];
	333	if (lab == TMath::Abs(c->GetLabel(0)) \|\|
	334	lab == TMath::Abs(c->GetLabel(1)) \|\|
	335	lab == TMath::Abs(c->GetLabel(2))) max++;
	336	}
	337	if (max >= Int_t(0.5*tail)) SetLabel(lab);
	338	}
	339
	340	delete[] lb;
	341	delete[] mx;
	342	delete[] clusters;
	343	}