* provided "as is" without express or implied warranty. *
**************************************************************************/
-//-------------------------------------------------------------------------
+/* $Id$ */
+
+///////////////////////////////////////////////////////////////////////////
// Implementation of the ITS track class
//
// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
// dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
-//-------------------------------------------------------------------------
-
-#include <TMatrixD.h>
-
+///////////////////////////////////////////////////////////////////////////
#include <TMath.h>
#include "AliCluster.h"
-#include "AliTPCtrack.h"
+#include "AliESDVertex.h"
+#include "AliITSReconstructor.h"
#include "AliITStrackV2.h"
+#include "AliTracker.h"
+
+const Int_t AliITStrackV2::fgkWARN = 5;
ClassImp(AliITStrackV2)
-const Int_t kWARN=5;
//____________________________________________________________________________
-AliITStrackV2::AliITStrackV2():AliKalmanTrack(),
- fX(0),
- fAlpha(0),
+AliITStrackV2::AliITStrackV2() : AliKalmanTrack(),
+ fCheckInvariant(kTRUE),
fdEdx(0),
- fP0(0),
- fP1(0),
- fP2(0),
- fP3(0),
- fP4(0),
- fC00(0),
- fC10(0),
- fC11(0),
- fC20(0),
- fC21(0),
- fC22(0),
- fC30(0),
- fC31(0),
- fC32(0),
- fC33(0),
- fC40(0),
- fC41(0),
- fC42(0),
- fC43(0),
- fC44(0)
- {
- for(Int_t i=0; i<kMaxLayer; i++) fIndex[i]=0;
+ fESDtrack(0)
+{
+ for(Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) {fIndex[i]=-1; fModule[i]=-1;}
for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
}
+
+
//____________________________________________________________________________
-AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) :
-AliKalmanTrack(t) {
+AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
+ AliKalmanTrack(),
+ fCheckInvariant(kTRUE),
+ fdEdx(t.GetITSsignal()),
+ fESDtrack(&t)
+{
//------------------------------------------------------------------
- //Conversion TPC track -> ITS track
+ // Conversion ESD track -> ITS track.
+ // If c==kTRUE, create the ITS track out of the constrained params.
//------------------------------------------------------------------
- SetChi2(0.);
- SetNumberOfClusters(0);
-
- fdEdx = t.GetdEdx();
- SetMass(t.GetMass());
+ const AliExternalTrackParam *par=&t;
+ if (c) {
+ par=t.GetConstrainedParam();
+ if (!par) throw "AliITStrackV2: conversion failed !\n";
+ }
+ Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance());
- fAlpha = t.GetAlpha();
- if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
- else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
+ //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
- //Conversion of the track parameters
- Double_t x,p[5]; t.GetExternalParameters(x,p);
- fX=x; x=GetConvConst();
- fP0=p[0];
- fP1=p[1];
- fP2=p[2];
- fP3=p[3];
- fP4=p[4]/x;
+ SetLabel(t.GetLabel());
+ SetMass(t.GetMass());
+ SetNumberOfClusters(t.GetITSclusters(fIndex));
- //Conversion of the covariance matrix
- Double_t c[15]; t.GetExternalCovariance(c);
+ if (t.GetStatus()&AliESDtrack::kTIME) {
+ StartTimeIntegral();
+ Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
+ SetIntegratedLength(t.GetIntegratedLength());
+ }
- fC00=c[0 ];
- fC10=c[1 ]; fC11=c[2 ];
- fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ];
- fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ];
- fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x;
+ for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
+}
- if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
+//____________________________________________________________________________
+void AliITStrackV2::ResetClusters() {
+ //------------------------------------------------------------------
+ // Reset the array of attached clusters.
+ //------------------------------------------------------------------
+ for (Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) fIndex[i]=-1;
+ SetChi2(0.);
+ SetNumberOfClusters(0);
+}
+//____________________________________________________________________________
+void AliITStrackV2::UpdateESDtrack(ULong_t flags) const {
+ // Update track params
+ fESDtrack->UpdateTrackParams(this,flags);
+ // copy the module indices
+ for(Int_t i=0;i<12;i++) {
+ // printf(" %d\n",GetModuleIndex(i));
+ fESDtrack->SetITSModuleIndex(i,GetModuleIndex(i));
+ }
+ // copy the 4 dedx samples
+ Double_t sdedx[4]={0.,0.,0.,0.};
+ for(Int_t i=0; i<4; i++) sdedx[i]=fdEdxSample[i];
+ fESDtrack->SetITSdEdxSamples(sdedx);
}
//____________________________________________________________________________
-AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) {
+AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) :
+ AliKalmanTrack(t),
+ fCheckInvariant(t.fCheckInvariant),
+ fdEdx(t.fdEdx),
+ fESDtrack(t.fESDtrack)
+{
//------------------------------------------------------------------
//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];
- if (i<4) fdEdxSample[i]=t.fdEdxSample[i];
+ Int_t i;
+ for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i];
+ for (i=0; i<2*AliITSgeomTGeo::GetNLayers(); i++) {
+ fIndex[i]=t.fIndex[i];
+ fModule[i]=t.fModule[i];
}
}
// This function compares tracks according to the their curvature
//-----------------------------------------------------------------
AliITStrackV2 *t=(AliITStrackV2*)o;
- //Double_t co=TMath::Abs(t->Get1Pt());
- //Double_t c =TMath::Abs(Get1Pt());
+ //Double_t co=OneOverPt();
+ //Double_t c =OneOverPt();
Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
Double_t c =GetSigmaY2()*GetSigmaZ2();
if (c>co) return 1;
return 0;
}
-//_____________________________________________________________________________
-void AliITStrackV2::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=GetConvConst();
-
- cc[0 ]=fC00;
- cc[1 ]=fC10; cc[2 ]=fC11;
- cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22;
- cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33;
- cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a;
-}
-
//____________________________________________________________________________
-Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) {
+Bool_t
+AliITStrackV2::PropagateToVertex(const AliESDVertex *v,Double_t d,Double_t x0)
+{
//------------------------------------------------------------------
//This function propagates a track to the minimal distance from the origin
- //------------------------------------------------------------------
- //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim.
- Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2));
- Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf);
- Double_t xv=(snf - fP2)/fP4 + fX;
- return PropagateTo(xv,d,x0);
+ //------------------------------------------------------------------
+ Double_t bz=GetBz();
+ if (PropagateToDCA(v,bz,kVeryBig)) {
+ Double_t xOverX0,xTimesRho;
+ xOverX0 = d; xTimesRho = d*x0;
+ if (CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kTRUE;
+ }
+ return kFALSE;
}
//____________________________________________________________________________
-Int_t AliITStrackV2::
-GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const {
+Bool_t AliITStrackV2::
+GetGlobalXYZat(Double_t xloc, Double_t &x, Double_t &y, Double_t &z) const {
//------------------------------------------------------------------
//This function returns a track position in the global system
//------------------------------------------------------------------
- Double_t dx=xk-fX;
- Double_t f1=fP2, f2=f1 + fP4*dx;
- if (TMath::Abs(f2) >= 0.9999) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("GetGlobalXYZat","Propagation failed (%d) !\n",n);
- return 0;
- }
-
- Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2);
-
- Double_t yk = fP0 + dx*(f1+f2)/(r1+r2);
- Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
-
- Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha);
- x = xk*cs - yk*sn;
- y = xk*sn + yk*cs;
- z = zk;
-
- return 1;
+ Double_t r[3];
+ Bool_t rc=GetXYZAt(xloc, GetBz(), r);
+ x=r[0]; y=r[1]; z=r[2];
+ return rc;
}
//_____________________________________________________________________________
-Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const
-{
+Double_t AliITStrackV2::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-30) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("GetPredictedChi2","Singular matrix (%d) !\n",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;
+ Double_t p[2]={c->GetY(), c->GetZ()};
+ Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
+ return AliExternalTrackParam::GetPredictedChi2(p,cov);
}
//____________________________________________________________________________
-Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) {
+Bool_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) {
//------------------------------------------------------------------
- //This function corrects the track parameters for crossed material
+ //This function propagates a track
//------------------------------------------------------------------
- Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
- Double_t beta2=p2/(p2 + GetMass()*GetMass());
- d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2));
-
- //Multiple scattering******************
- if (d!=0) {
- Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d);
- //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33;
- fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3);
- fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3);
- fC43 += theta2*fP3*fP4*(1. + fP3*fP3);
- fC44 += theta2*fP3*fP4*fP3*fP4;
- }
- //Energy losses************************
- if (x0!=0.) {
- d*=x0;
- Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
- fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE);
+ Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
+
+ //Double_t bz=GetBz();
+ //if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
+ Double_t b[3]; GetBxByBz(b);
+ if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) return kFALSE;
+ Double_t xOverX0,xTimesRho;
+ xOverX0 = d; xTimesRho = d*x0;
+ if (!CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kFALSE;
+
+ Double_t x=GetX(), y=GetY(), z=GetZ();
+ if (IsStartedTimeIntegral() && x>oldX) {
+ Double_t l2 = (x-oldX)*(x-oldX) + (y-oldY)*(y-oldY) + (z-oldZ)*(z-oldZ);
+ AddTimeStep(TMath::Sqrt(l2));
}
- if (!Invariant()) return 0;
-
- return 1;
+ return kTRUE;
}
//____________________________________________________________________________
-Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) {
- //------------------------------------------------------------------
- //This function propagates a track
- //------------------------------------------------------------------
- Double_t x1=fX, x2=xk, dx=x2-x1;
- Double_t f1=fP2, f2=f1 + fP4*dx;
- if (TMath::Abs(f2) >= 0.9999) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("PropagateTo","Propagation failed !\n",n);
- return 0;
- }
+Bool_t AliITStrackV2::PropagateToTGeo(Double_t xToGo, Int_t nstep, Double_t &xOverX0, Double_t &xTimesRho, Bool_t addTime) {
+ //-------------------------------------------------------------------
+ // Propagates the track to a reference plane x=xToGo in n steps.
+ // These n steps are only used to take into account the curvature.
+ // The material is calculated with TGeo. (L.Gaudichet)
+ //-------------------------------------------------------------------
+
+ Double_t startx = GetX(), starty = GetY(), startz = GetZ();
+ Double_t sign = (startx<xToGo) ? -1.:1.;
+ Double_t step = (xToGo-startx)/TMath::Abs(nstep);
- // old position [SR, GSI, 17.02.2003]
- Double_t oldX = fX, oldY = fP0, oldZ = fP1;
+ Double_t start[3], end[3], mparam[7];
+ //Double_t bz = GetBz();
+ Double_t b[3]; GetBxByBz(b);
+ Double_t bz = b[2];
- Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2);
+ Double_t x = startx;
- fP0 += dx*(f1+f2)/(r1+r2);
- fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
- fP2 += dx*fP4;
+ for (Int_t i=0; i<nstep; i++) {
+
+ GetXYZ(start); //starting global position
+ x += step;
+ if (!GetXYZAt(x, bz, end)) return kFALSE;
+ //if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE;
+ if (!AliExternalTrackParam::PropagateToBxByBz(x, b)) return kFALSE;
+ AliTracker::MeanMaterialBudget(start, end, mparam);
+ xTimesRho = sign*mparam[4]*mparam[0];
+ xOverX0 = mparam[1];
+ if (mparam[1]<900000) {
+ if (!AliExternalTrackParam::CorrectForMeanMaterial(xOverX0,
+ xTimesRho,GetMass())) return kFALSE;
+ } else { // this happens when MeanMaterialBudget cannot cross a boundary
+ return kFALSE;
+ }
+ }
- //f = F - 1
-
- Double_t f02= dx/(r1*r1*r1);
- Double_t f04=0.5*dx*dx/(r1*r1*r1);
- Double_t f12= dx*fP3*f1/(r1*r1*r1);
- Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1);
- Double_t f13= dx/r1;
- Double_t f24= dx;
-
- //b = C*ft
- Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30;
- Double_t b02=f24*fC40;
- Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31;
- Double_t b12=f24*fC41;
- Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32;
- Double_t b22=f24*fC42;
- Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43;
- Double_t b42=f24*fC44;
- Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33;
- Double_t b32=f24*fC43;
-
- //a = f*b = f*C*ft
- Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42;
- Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32;
- Double_t a22=f24*b42;
-
- //F*C*Ft = C + (b + bt + a)
- fC00 += b00 + b00 + a00;
- fC10 += b10 + b01 + a01;
- fC20 += b20 + b02 + a02;
- fC30 += b30;
- fC40 += b40;
- fC11 += b11 + b11 + a11;
- fC21 += b21 + b12 + a12;
- fC31 += b31;
- fC41 += b41;
- fC22 += b22 + b22 + a22;
- fC32 += b32;
- fC42 += b42;
-
- fX=x2;
-
- if (!CorrectForMaterial(d,x0)) return 0;
-
- // Integrated Time [SR, GSI, 17.02.2003]
- if (IsStartedTimeIntegral() && fX>oldX) {
- Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+
- (fP1-oldZ)*(fP1-oldZ);
+ if (addTime && IsStartedTimeIntegral() && GetX()>startx) {
+ Double_t l2 = ( (GetX()-startx)*(GetX()-startx) +
+ (GetY()-starty)*(GetY()-starty) +
+ (GetZ()-startz)*(GetZ()-startz) );
AddTimeStep(TMath::Sqrt(l2));
}
- //
- return 1;
+ return kTRUE;
}
//____________________________________________________________________________
-Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) {
+Bool_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, Int_t index)
+{
//------------------------------------------------------------------
//This function updates track parameters
//------------------------------------------------------------------
- Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
- Double_t c00=fC00;
- Double_t c10=fC10, c11=fC11;
- Double_t c20=fC20, c21=fC21, c22=fC22;
- Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
- Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
-
-
- 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 sf=fP2 + k20*dy + k21*dz;
-
- fP0 += k00*dy + k01*dz;
- fP1 += k10*dy + k11*dz;
- fP2 = sf;
- fP3 += k30*dy + k31*dz;
- 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;
+ Double_t p[2]={c->GetY(), c->GetZ()};
+ Double_t cov[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
- fC11-=k10*c01+k11*fC11;
- fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13;
- fC41-=k10*c04+k11*c14;
+ if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
- 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;
+ Int_t n=GetNumberOfClusters();
+ if (!Invariant()) {
+ if (n>fgkWARN) AliWarning("Wrong invariant !");
+ return kFALSE;
+ }
- fC44-=k40*c04+k41*c14;
+ if (chi2<0) return kTRUE;
- if (!Invariant()) {
- fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
- fC00=c00;
- fC10=c10; fC11=c11;
- fC20=c20; fC21=c21; fC22=c22;
- fC30=c30; fC31=c31; fC32=c32; fC33=c33;
- fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
- return 0;
+ // fill residuals for ITS+TPC tracks
+ if (fESDtrack) {
+ if (fESDtrack->GetStatus()&AliESDtrack::kTPCin) {
+ AliTracker::FillResiduals(this,p,cov,c->GetVolumeId());
+ }
}
- Int_t n=GetNumberOfClusters();
fIndex[n]=index;
SetNumberOfClusters(n+1);
SetChi2(GetChi2()+chi2);
- return 1;
+ return kTRUE;
}
-Int_t AliITStrackV2::Invariant() const {
+Bool_t AliITStrackV2::Invariant() const {
//------------------------------------------------------------------
// This function is for debugging purpose only
//------------------------------------------------------------------
+ if(!fCheckInvariant) return kTRUE;
+
Int_t n=GetNumberOfClusters();
-
- if (TMath::Abs(fP2)>=0.9999){
- if (n>kWARN) Warning("Invariant","fP2=%f\n",fP2);
- return 0;
+
+ // take into account the misalignment error
+ Float_t maxMisalErrY2=0,maxMisalErrZ2=0;
+ for (Int_t lay=0; lay<AliITSgeomTGeo::kNLayers; lay++) {
+ maxMisalErrY2 = TMath::Max(maxMisalErrY2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorY(lay,GetBz()));
+ maxMisalErrZ2 = TMath::Max(maxMisalErrZ2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorZ(lay,GetBz()));
}
- if (fC00<=0 || fC00>9.) {
- if (n>kWARN) Warning("Invariant","fC00=%f\n",fC00);
- return 0;
+ maxMisalErrY2 *= maxMisalErrY2;
+ maxMisalErrZ2 *= maxMisalErrZ2;
+ // this is because when we reset before refitting, we multiply the
+ // matrix by 10
+ maxMisalErrY2 *= 10.;
+ maxMisalErrZ2 *= 10.;
+
+ Double_t sP2=GetParameter()[2];
+ if (TMath::Abs(sP2) >= kAlmost1){
+ if (n>fgkWARN) Warning("Invariant","fP2=%f\n",sP2);
+ return kFALSE;
}
- if (fC11<=0 || fC11>9.) {
- if (n>kWARN) Warning("Invariant","fC11=%f\n",fC11);
- return 0;
+ Double_t sC00=GetCovariance()[0];
+ if (sC00<=0 || sC00>(9.+maxMisalErrY2)) {
+ if (n>fgkWARN) Warning("Invariant","fC00=%f\n",sC00);
+ return kFALSE;
}
- if (fC22<=0 || fC22>1.) {
- if (n>kWARN) Warning("Invariant","fC22=%f\n",fC22);
- return 0;
+ Double_t sC11=GetCovariance()[2];
+ if (sC11<=0 || sC11>(9.+maxMisalErrZ2)) {
+ if (n>fgkWARN) Warning("Invariant","fC11=%f\n",sC11);
+ return kFALSE;
}
- if (fC33<=0 || fC33>1.) {
- if (n>kWARN) Warning("Invariant","fC33=%f\n",fC33);
- return 0;
+ Double_t sC22=GetCovariance()[5];
+ if (sC22<=0 || sC22>1.) {
+ if (n>fgkWARN) Warning("Invariant","fC22=%f\n",sC22);
+ return kFALSE;
}
- if (fC44<=0 || fC44>6e-5) {
- if (n>kWARN) Warning("Invariant","fC44=%f\n",fC44);
- return 0;
+ Double_t sC33=GetCovariance()[9];
+ if (sC33<=0 || sC33>1.) {
+ if (n>fgkWARN) Warning("Invariant","fC33=%f\n",sC33);
+ return kFALSE;
}
- return 1;
+ Double_t sC44=GetCovariance()[14];
+ if (sC44<=0 /*|| sC44>6e-5*/) {
+ if (n>fgkWARN) Warning("Invariant","fC44=%f\n",sC44);
+ return kFALSE;
+ }
+
+ return kTRUE;
}
//____________________________________________________________________________
-Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) {
+Bool_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) {
//------------------------------------------------------------------
//This function propagates a track
//------------------------------------------------------------------
- Double_t alpha=fAlpha, x=fX;
- Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
- Double_t c00=fC00;
- Double_t c10=fC10, c11=fC11;
- Double_t c20=fC20, c21=fC21, c22=fC22;
- Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
- Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
-
- if (alp < -TMath::Pi()) alp += 2*TMath::Pi();
- else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi();
- Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha);
- Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2);
-
- TMatrixD *T=0;
- // **** rotation **********************
- {
- fAlpha = alp;
- fX = x*ca + p0*sa;
- fP0= -x*sa + p0*ca;
- fP2= sf*ca - cf*sa;
-
- TMatrixD C(5,5);
- C(0,0)=c00;
- C(1,0)=c10; C(1,1)=c11;
- C(2,0)=c20; C(2,1)=c21; C(2,2)=c22;
- C(3,0)=c30; C(3,1)=c31; C(3,2)=c32; C(3,3)=c33;
- C(4,0)=c40; C(4,1)=c41; C(4,2)=c42; C(4,3)=c43; C(4,4)=c44;
- C(0,1)=C(1,0);
- C(0,2)=C(2,0); C(1,2)=C(2,1);
- C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2);
- C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3);
-
- TMatrixD F(6,5);
- F(0,0)=sa;
- F(1,0)=ca;
- F(2,1)=F(4,3)=F(5,4)=1;
- F(3,2)=ca + sf/cf*sa;
-
- TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F));
- T=new TMatrixD(F,TMatrixD::kMult,tmp);
- }
-
- // **** translation ******************
- {
- Double_t dx=xk-fX;
- Double_t f1=fP2, f2=f1 + fP4*dx;
- if (TMath::Abs(f2) >= 0.9999) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("Propagate","Propagation failed (%d) !\n",n);
- return 0;
- }
- Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
-
- fX=xk;
- fP0 += dx*(f1+f2)/(r1+r2);
- fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
- fP2 += dx*fP4;
-
- TMatrixD F(5,6);
- F(0,1)=F(1,2)=F(2,3)=F(3,4)=F(4,5)=1;
- F(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2));
- F(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2));
- F(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1));
- F(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1);
- F(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1));
- F(2,5)=dx;
- F(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2));
- F(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1)));
- F(2,0)=-fP4;
-
- TMatrixD tmp(*T,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F));
- delete T;
- TMatrixD C(F,TMatrixD::kMult,tmp);
-
- fC00=C(0,0);
- fC10=C(1,0); fC11=C(1,1);
- fC20=C(2,0); fC21=C(2,1); fC22=C(2,2);
- fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3);
- fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4);
+ //Double_t bz=GetBz();
+ //if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE;
+ Double_t b[3]; GetBxByBz(b);
+ if (!AliExternalTrackParam::PropagateBxByBz(alp,xk,b)) return kFALSE;
if (!Invariant()) {
- fAlpha=alpha;
- fX=x;
- fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
- fC00=c00;
- fC10=c10; fC11=c11;
- fC20=c20; fC21=c21; fC22=c22;
- fC30=c30; fC31=c31; fC32=c32; fC33=c33;
- fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
- return 0;
- }
+ Int_t n=GetNumberOfClusters();
+ if (n>fgkWARN) AliWarning("Wrong invariant !");
+ return kFALSE;
}
- return 1;
+ return kTRUE;
}
-Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const {
- //------------------------------------------------------------------
- // This function calculates the transverse impact parameter
- // with respect to a point with global coordinates (x,y)
- //------------------------------------------------------------------
- Double_t xt=fX, yt=fP0;
+Bool_t AliITStrackV2::MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const {
+
+ //-------------------------------------------------------------------
+ // Get the mean material budget between the actual point and the
+ // primary vertex. (L.Gaudichet)
+ //-------------------------------------------------------------------
+
+ Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
+ Double_t vertexX = xyz[0]*cs + xyz[1]*sn;
+
+ Int_t nstep = Int_t((GetX()-vertexX)/step);
+ if (nstep<1) nstep = 1;
+ step = (GetX()-vertexX)/nstep;
- Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha);
- Double_t a = x*cs + y*sn;
- y = -x*sn + y*cs; x=a;
- xt-=x; yt-=y;
+ // Double_t mparam[7], densMean=0, radLength=0, length=0;
+ Double_t mparam[7];
+ Double_t p1[3], p2[3], x = GetX(), bz = GetBz();
+ GetXYZ(p1);
+
+ d=0.;
+
+ for (Int_t i=0; i<nstep; i++) {
+ x += step;
+ if (!GetXYZAt(x, bz, p2)) return kFALSE;
+ AliTracker::MeanMaterialBudget(p1, p2, mparam);
+ if (mparam[1]>900000) return kFALSE;
+ d += mparam[1];
+
+ p1[0] = p2[0];
+ p1[1] = p2[1];
+ p1[2] = p2[2];
+ }
- sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2);
- a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt);
- if (fP4<0) a=-a;
- return a/(1 + TMath::Sqrt(sn*sn + cs*cs));
+ return kTRUE;
}
-Int_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) {
+Bool_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) {
//------------------------------------------------------------------
- //This function improves angular track parameters
+ //This function improves angular track parameters
//------------------------------------------------------------------
- Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha);
- //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
- Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
- Double_t zv = xyz[2]; // local frame
- Double_t dy=fP0-yv, dz=fP1-zv;
- Double_t r2=fX*fX+dy*dy;
- Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
+ //Store the initail track parameters
+
+ Double_t x = GetX();
+ Double_t alpha = GetAlpha();
+ Double_t par[] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()};
+ Double_t cov[] = {
+ GetSigmaY2(),
+ GetSigmaZY(),
+ GetSigmaZ2(),
+ GetSigmaSnpY(),
+ GetSigmaSnpZ(),
+ GetSigmaSnp2(),
+ GetSigmaTglY(),
+ GetSigmaTglZ(),
+ GetSigmaTglSnp(),
+ GetSigmaTgl2(),
+ GetSigma1PtY(),
+ GetSigma1PtZ(),
+ GetSigma1PtSnp(),
+ GetSigma1PtTgl(),
+ GetSigma1Pt2()
+ };
+
+
+ Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
+//Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
+ Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
+ Double_t zv = xyz[2]; // local frame
+
+ Double_t dy = par[0] - yv, dz = par[1] - zv;
+ Double_t r2=GetX()*GetX() + dy*dy;
+ Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt());
Double_t beta2=p2/(p2 + GetMass()*GetMass());
x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
//Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
+
+ Double_t cnv=GetBz()*kB2C;
{
- Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4));
- Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
- sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
- sigma2p += ers[1]*ers[1]/r2;
- sigma2p += 0.25*fC44*fX*fX;
- Double_t eps2p=sigma2p/(fC22+sigma2p);
- fP0 += fC20/(fC22+sigma2p)*(parp-fP2);
- fP2 = eps2p*fP2 + (1-eps2p)*parp;
- fC22 *= eps2p;
- fC20 *= eps2p;
+ Double_t dummy = 4/r2 - GetC()*GetC();
+ if (dummy < 0) return kFALSE;
+ Double_t parp = 0.5*(GetC()*GetX() + dy*TMath::Sqrt(dummy));
+ Double_t sigma2p = theta2*(1.-GetSnp())*(1.+GetSnp())*(1. + GetTgl()*GetTgl());
+ Double_t ovSqr2 = 1./TMath::Sqrt(r2);
+ Double_t tfact = ovSqr2*(1.-dy*ovSqr2)*(1.+dy*ovSqr2);
+ sigma2p += cov[0]*tfact*tfact;
+ sigma2p += ers[1]*ers[1]/r2;
+ sigma2p += 0.25*cov[14]*cnv*cnv*GetX()*GetX();
+ Double_t eps2p=sigma2p/(cov[5] + sigma2p);
+ par[0] += cov[3]/(cov[5] + sigma2p)*(parp - GetSnp());
+ par[2] = eps2p*GetSnp() + (1 - eps2p)*parp;
+ cov[5] *= eps2p;
+ cov[3] *= eps2p;
}
{
- Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2));
- Double_t sigma2l=theta2;
- sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2);
- sigma2l += ers[2]*ers[2]/r2;
- Double_t eps2l=sigma2l/(fC33+sigma2l);
- fP1 += fC31/(fC33+sigma2l)*(parl-fP3);
- fP4 += fC43/(fC33+sigma2l)*(parl-fP3);
- fP3 = eps2l*fP3 + (1-eps2l)*parl;
- fC33 *= eps2l; fC43 *= eps2l;
- fC31 *= eps2l;
+ Double_t parl=0.5*GetC()*dz/TMath::ASin(0.5*GetC()*TMath::Sqrt(r2));
+ Double_t sigma2l=theta2;
+ sigma2l += cov[2]/r2 + cov[0]*dy*dy*dz*dz/(r2*r2*r2);
+ sigma2l += ers[2]*ers[2]/r2;
+ Double_t eps2l = sigma2l/(cov[9] + sigma2l);
+ par[1] += cov[7 ]/(cov[9] + sigma2l)*(parl - par[3]);
+ par[4] += cov[13]/(cov[9] + sigma2l)*(parl - par[3]);
+ par[3] = eps2l*par[3] + (1-eps2l)*parl;
+ cov[9] *= eps2l;
+ cov[13]*= eps2l;
+ cov[7] *= eps2l;
}
- if (!Invariant()) return 0;
- return 1;
-}
-/*
-Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) {
- //------------------------------------------------------------------
- //This function improves angular track parameters
- //------------------------------------------------------------------
- Double_t dy=fP0-yv, dz=fP1-zv;
- Double_t r2=fX*fX+dy*dy;
- Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
- Double_t beta2=p2/(p2 + GetMass()*GetMass());
- x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
- //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
- Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
-
- Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4));
- Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
- sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
- sigma2 += kSigmaYV*kSigmaYV/r2;
- sigma2 += 0.25*fC44*fX*fX;
- Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2);
- if (10*r2*fC44<fC22) {
- fP2 = eps2*fP2 + (1-eps2)*par;
- fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps;
- }
+ Set(x,alpha,par,cov);
- par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2));
- sigma2=theta2;
- sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2);
- sigma2 += kSigmaZV*kSigmaZV/r2;
- eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2);
- Double_t tgl=fP3;
- fP3 = eps2*fP3 + (1-eps2)*par;
- fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps;
-
- eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl));
- fP4*=eps;
- fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps;
-
- if (!Invariant()) return 0;
- return 1;
-}
-*/
-void AliITStrackV2::ResetCovariance() {
- //------------------------------------------------------------------
- //This function makes a track forget its history :)
- //------------------------------------------------------------------
-
- fC00*=10.;
- fC10=0.; fC11*=10.;
- fC20=0.; fC21=0.; fC22*=10.;
- fC30=0.; fC31=0.; fC32=0.; fC33*=10.;
- fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.;
+ if (!Invariant()) return kFALSE;
+ return kTRUE;
}
void AliITStrackV2::CookdEdx(Double_t low, Double_t up) {
//-----------------------------------------------------------------
// This function calculates dE/dX within the "low" and "up" cuts.
// Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
+ // Updated: F. Prino 8-June-2009
//-----------------------------------------------------------------
- Int_t i;
- Int_t nc=4;
- // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1
- // Take only SSD and SDD
+ // The cluster order is: SDD-1, SDD-2, SSD-1, SSD-2
+
+ Int_t nc=0;
+ Float_t dedx[4];
+ for (Int_t il=0; il<4; il++) { // count good (>0) dE/dx values
+ if(fdEdxSample[il]>0.){
+ dedx[nc]= fdEdxSample[il];
+ nc++;
+ }
+ }
+ if(nc<1){
+ SetdEdx(0.);
+ return;
+ }
- Int_t swap;//stupid sorting
+ Int_t swap; // sort in ascending order
do {
swap=0;
- for (i=0; i<nc-1; i++) {
- if (fdEdxSample[i]<=fdEdxSample[i+1]) continue;
- Float_t tmp=fdEdxSample[i];
- fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp;
+ for (Int_t i=0; i<nc-1; i++) {
+ if (dedx[i]<=dedx[i+1]) continue;
+ Float_t tmp=dedx[i];
+ dedx[i]=dedx[i+1];
+ dedx[i+1]=tmp;
swap++;
}
} while (swap);
- Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX
- // values from four ones choose
- // nu=2
- Float_t dedx=0;
- for (i=nl; i<nu; i++) dedx += fdEdxSample[i];
- dedx /= (nu-nl);
- SetdEdx(dedx);
+ Double_t nl=low*nc, nu =up*nc;
+ Float_t sumamp = 0;
+ Float_t sumweight =0;
+ for (Int_t i=0; i<nc; i++) {
+ Float_t weight =1;
+ if (i<nl+0.1) weight = TMath::Max(1.-(nl-i),0.);
+ if (i>nu-1) weight = TMath::Max(nu-i,0.);
+ sumamp+= dedx[i]*weight;
+ sumweight+=weight;
+ }
+ SetdEdx(sumamp/sumweight);
+}
+
+//____________________________________________________________________________
+Bool_t AliITStrackV2::
+GetPhiZat(Double_t r, Double_t &phi, Double_t &z) const {
+ //------------------------------------------------------------------
+ // This function returns the global cylindrical (phi,z) of the track
+ // position estimated at the radius r.
+ // The track curvature is neglected.
+ //------------------------------------------------------------------
+ Double_t d=GetD(0.,0.);
+ if (TMath::Abs(d) > r) {
+ if (r>1e-1) return kFALSE;
+ r = TMath::Abs(d);
+ }
+
+ Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
+ if (TMath::Abs(d) > rcurr) return kFALSE;
+ Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
+ Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
+
+ if (GetX()>=0.) {
+ phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
+ } else {
+ phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
+ }
+
+ // return a phi in [0,2pi[
+ if (phi<0.) phi+=2.*TMath::Pi();
+ else if (phi>=2.*TMath::Pi()) phi-=2.*TMath::Pi();
+ z=GetZ()+GetTgl()*(TMath::Sqrt((r-d)*(r+d))-TMath::Sqrt((rcurr-d)*(rcurr+d)));
+ return kTRUE;
+}
+//____________________________________________________________________________
+Bool_t AliITStrackV2::
+GetLocalXat(Double_t r,Double_t &xloc) const {
+ //------------------------------------------------------------------
+ // This function returns the local x of the track
+ // position estimated at the radius r.
+ // The track curvature is neglected.
+ //------------------------------------------------------------------
+ Double_t d=GetD(0.,0.);
+ if (TMath::Abs(d) > r) {
+ if (r>1e-1) return kFALSE;
+ r = TMath::Abs(d);
+ }
+
+ Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
+ Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
+ Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
+ Double_t phi;
+ if (GetX()>=0.) {
+ phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
+ } else {
+ phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
+ }
+
+ xloc=r*(TMath::Cos(phi)*TMath::Cos(GetAlpha())
+ +TMath::Sin(phi)*TMath::Sin(GetAlpha()));
+
+ return kTRUE;
}
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff