* provided "as is" without express or implied warranty. *
**************************************************************************/
-/*
-$Log$
-*/
+// $Id$
+
+///////////////////////////////////////////////////////////////////////////
+// Class AliTrack
+// Handling of the attributes of a reconstructed particle track.
+//
+// Coding example :
+// ----------------
+//
+// Float_t a[4]={195.,1.2,-0.04,8.5};
+// Ali4Vector pmu;
+// pmu.SetVector(a,"car");
+// AliTrack t1;
+// t1.Set4Momentum(pmu);
+//
+// Float_t b[3]={1.2,-0.04,8.5};
+// Ali3Vector p;
+// p.SetVector(b,"car");
+// AliTrack t2;
+// t2.Set3Momentum(p);
+// t2.SetCharge(0);
+// t2.SetMass(1.115);
+//
+// t1.Info();
+// t2.Info();
+//
+// Float_t pi=acos(-1.);
+// Float_t thcms=0.2*pi; // decay theta angle in cms
+// Float_t phicms=pi/4.; // decay theta angle in cms
+// Float_t m1=0.938;
+// Float_t m2=0.140;
+// t2.Decay(m1,m2,thcms,phicms); // Track t2 decay : Lambda -> proton + pion
+//
+// t2.List();
+//
+// Int_t ndec=t2.GetNdecay();
+// AliTrack* d1=t2.GetDecayTrack(1); // Access to decay track number 1
+// AliTrack* d2=t2.GetDecayTrack(2); // Access to decay track number 2
+//
+// AliSignal s1,s2,s3,s4;
+//
+// .... // Code (e.g. detector readout) to fill AliSignal data
+//
+// AliTrack trec; // Track which will be reconstructed from signals
+// trec.AddSignal(s1);
+// trec.AddSignal(s3);
+// trec.AddSignal(s4);
+//
+// Ali3Vector P;
+// Float_t Q,M;
+//
+// ... // Code which accesses signals from trec and reconstructs
+// 3-momentum P, charge Q, mass M etc...
+//
+// trec.Set3Momentum(P);
+// trec.SetCharge(Q);
+// trec.SetMass(M);
+//
+// Float_t r1[3]={1.6,-3.8,25.7};
+// Float_t er1[3]={0.2,0.5,1.8};
+// Float_t r2[3]={8.6,23.8,-6.7};
+// Float_t er2[3]={0.93,1.78,0.8};
+// AliPosition begin,end;
+// begin.SetPosition(r1,"car");
+// begin.SetPositionErrors(er1,"car");
+// end.SetPosition(r2,"car");
+// end.SetPositionErrors(er2,"car");
+// trec.SetBeginPoint(begin);
+// trec.SetEndPoint(end);
+//
+// Note : All quantities are in GeV, GeV/c or GeV/c**2
+//
+//--- Author: Nick van Eijndhoven 10-jul-1997 UU-SAP Utrecht
+//- Modified: NvE $Date$ UU-SAP Utrecht
+///////////////////////////////////////////////////////////////////////////
#include "AliTrack.h"
// Default constructor
// All variables initialised to 0
fDecays=0;
+ fSignals=0;
+ fMasses=0;
+ fDmasses=0;
+ fPmasses=0;
Reset();
}
///////////////////////////////////////////////////////////////////////////
delete fDecays;
fDecays=0;
}
+ if (fSignals)
+ {
+ fSignals->Clear();
+ delete fSignals;
+ fSignals=0;
+ }
}
///////////////////////////////////////////////////////////////////////////
void AliTrack::Reset()
{
-// Reset all variables to 0
- fM=0;
+// Reset all variables to 0 and delete all auto-generated decay tracks.
fQ=0;
+ fUserId=0;
fNdec=0;
+ fNsig=0;
+ fNmasses=0;
Double_t a[4]={0,0,0,0};
SetVector(a,"sph");
if (fDecays)
delete fDecays;
fDecays=0;
}
+ if (fSignals)
+ {
+ fSignals->Clear();
+ delete fSignals;
+ fSignals=0;
+ }
+ Double_t b[3]={0,0,0};
+ fBegin.SetPosition(b,"sph");
+ fEnd.SetPosition(b,"sph");
+ fImpactXY.SetPosition(b,"sph");
+ fImpactXZ.SetPosition(b,"sph");
+ fImpactYZ.SetPosition(b,"sph");
+ fClosest.SetPosition(b,"sph");
+ if (fMasses)
+ {
+ delete fMasses;
+ fMasses=0;
+ }
+ if (fDmasses)
+ {
+ delete fDmasses;
+ fDmasses=0;
+ }
+ if (fPmasses)
+ {
+ delete fPmasses;
+ fPmasses=0;
+ }
}
///////////////////////////////////////////////////////////////////////////
void AliTrack::Set3Momentum(Ali3Vector& p)
{
// Set the track parameters according to the 3-momentum p
- Double_t E=sqrt(p.Dot(p)+fM*fM);
- SetVector(E,p);
+ Set3Vector(p);
}
///////////////////////////////////////////////////////////////////////////
void AliTrack::Set4Momentum(Ali4Vector& p)
{
// Set the track parameters according to the 4-momentum p
Double_t E=p.GetScalar();
+ Double_t dE=p.GetResultError();
Ali3Vector pv=p.Get3Vector();
SetVector(E,pv);
-
- Double_t m2=p.Dot(p);
- fM=0;
- if (m2 > 0.) fM=sqrt(m2);
+ SetScalarError(dE);
}
///////////////////////////////////////////////////////////////////////////
-void AliTrack::SetMass(Double_t m)
+void AliTrack::SetMass(Double_t m,Double_t dm)
{
// Set the particle mass
- fM=m;
- Ali3Vector p=Get3Vector();
- Double_t E=sqrt(p.Dot(p)+fM*fM);
- SetVector(E,p);
+// The default value for the error dm is 0.
+ Double_t inv=pow(m,2);
+ Double_t dinv=fabs(2.*m*dm);
+ SetInvariant(inv,dinv);
}
///////////////////////////////////////////////////////////////////////////
void AliTrack::SetCharge(Float_t q)
void AliTrack::Info(TString f)
{
// Provide track information within the coordinate frame f
- cout << " *AliTrack::Info* Mass : " << fM << " Charge : " << fQ
- << " Momentum : " << GetMomentum() << " Ntracks : " << fNdec << endl;
- cout << " ";
+ Double_t m=GetMass();
+ Double_t dm=GetResultError();
+ cout << " *AliTrack::Info* Id : " << fUserId << " Mass : " << m
+ << " error : " << dm << " Charge : " << fQ
+ << " Momentum : " << GetMomentum() << " Nmass hyp. : " << fNmasses
+ << " Ntracks : " << fNdec << " Nsignals : " << fNsig << endl;
+ for (Int_t i=0; i<fNmasses; i++)
+ {
+ cout << " Mass hypothesis " << (i+1) << " Mass : " << fMasses->At(i)
+ << " error : " << fDmasses->At(i) << " prob. : " << fPmasses->At(i)
+ << endl;
+ }
Ali4Vector::Info(f);
}
///////////////////////////////////////////////////////////////////////////
if (td)
{
cout << " ---Level 1 sec. track no. " << id << endl;
- cout << " ";
td->Info(f);
}
else
// Provide complete track and decay information within the coordinate frame f
Info(f); // Information of the current track
+ cout << " Begin-point :"; fBegin.Info(f);
+ cout << " End-point :"; fEnd.Info(f);
+ for (Int_t is=1; is<=GetNsignals(); is++)
+ {
+ ((AliSignal*)GetSignal(is))->Info(f);
+ }
AliTrack* t=this;
Dump(t,1,f); // Information of all decay products
if (td)
{
cout << " ---Level " << n << " sec. track no. " << id << endl;
- cout << " ";
td->Info(f);
+ for (Int_t is=1; is<=td->GetNsignals(); is++)
+ {
+ ((AliSignal*)td->GetSignal(is))->Info(f);
+ }
// Go for next decay level of this decay track recursively
Dump(td,n+1,f);
//////////////////////////////////////////////////////////////////////////
Double_t AliTrack::GetMomentum()
{
-// Provide the value of the track 3-momentum
- Ali3Vector p=Get3Vector();
- return sqrt(p.Dot(p));
+// Provide the value of the track 3-momentum.
+// The error can be obtained by invoking GetResultError() after
+// invokation of GetMomentum().
+ Double_t norm=fV.GetNorm();
+ fDresult=fV.GetResultError();
+ return norm;
}
///////////////////////////////////////////////////////////////////////////
Ali3Vector AliTrack::Get3Momentum()
///////////////////////////////////////////////////////////////////////////
Double_t AliTrack::GetMass()
{
-// Provide the particle mass
- return fM;
+// Provide the particle mass.
+// The error can be obtained by invoking GetResultError() after
+// invokation of GetMass().
+ Double_t inv=GetInvariant();
+ Double_t dinv=GetResultError();
+ Double_t dm=0;
+ if (inv >= 0)
+ {
+ Double_t m=sqrt(inv);
+ if (m) dm=dinv/(2.*m);
+ fDresult=dm;
+ return m;
+ }
+ else
+ {
+ cout << "*AliTrack::GetMass* Unphysical situation m**2 = " << inv << endl;
+ cout << " Value 0 will be returned." << endl;
+ fDresult=dm;
+ return 0;
+ }
}
///////////////////////////////////////////////////////////////////////////
Float_t AliTrack::GetCharge()
///////////////////////////////////////////////////////////////////////////
Double_t AliTrack::GetEnergy()
{
-// Provide the particle's energy
- return GetScalar();
+// Provide the particle's energy.
+// The error can be obtained by invoking GetResultError() after
+// invokation of GetEnergy().
+ Double_t E=GetScalar();
+ if (E>0)
+ {
+ return E;
+ }
+ else
+ {
+ cout << "*AliTrack::GetEnergy* Unphysical situation E = " << E << endl;
+ cout << " Value 0 will be returned." << endl;
+ return 0;
+ }
}
///////////////////////////////////////////////////////////////////////////
void AliTrack::Decay(Double_t m1,Double_t m2,Double_t thcms,Double_t phicms)
// phicms : cms phi decay angle (in rad.) of m1
fNdec=2; // it's a 2-body decay
+
+ Double_t M=GetMass();
// Compute the 4-momenta of the decay products in the cms
// Note : p2=p1=pnorm for a 2-body decay
- Double_t e1=((fM*fM)+(m1*m1)-(m2*m2))/(2.*fM);
- Double_t e2=((fM*fM)+(m2*m2)-(m1*m1))/(2.*fM);
+ Double_t e1=0;
+ if (M) e1=((M*M)+(m1*m1)-(m2*m2))/(2.*M);
+ Double_t e2=0;
+ if (M) e2=((M*M)+(m2*m2)-(m1*m1))/(2.*M);
Double_t pnorm=(e1*e1)-(m1*m1);
if (pnorm>0.)
{
Ali4Vector pprim1;
pprim1.SetVector(e1,p);
+ pprim1.SetInvariant(m1*m1);
Ali4Vector pprim2;
p*=-1;
pprim2.SetVector(e2,p);
+ pprim2.SetInvariant(m2*m2);
// Determine boost parameters from the parent particle
- Double_t E=GetScalar();
+ Double_t E=GetEnergy();
p=Get3Vector();
Ali4Vector pmu;
pmu.SetVector(E,p);
fDecays->Add(new AliTrack);
((AliTrack*)fDecays->At(0))->Set4Momentum(p1);
+ ((AliTrack*)fDecays->At(0))->SetMass(m1);
fDecays->Add(new AliTrack);
((AliTrack*)fDecays->At(1))->Set4Momentum(p2);
-
-// Set the mass values to m1 and m2 to omit roundoff errors
- ((AliTrack*)fDecays->At(0))->SetMass(m1);
((AliTrack*)fDecays->At(1))->SetMass(m2);
}
///////////////////////////////////////////////////////////////////////////
}
}
///////////////////////////////////////////////////////////////////////////
+void AliTrack::AddSignal(AliSignal& s)
+{
+// Relate an AliSignal object to this track.
+ if (!fSignals) fSignals=new TObjArray();
+ fNsig++;
+ fSignals->Add(&s);
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::RemoveSignal(AliSignal& s)
+{
+// Remove related AliSignal object to this track.
+ if (fSignals)
+ {
+ AliSignal* test=(AliSignal*)fSignals->Remove(&s);
+ if (test)
+ {
+ fNsig--;
+ fSignals->Compress();
+ }
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliTrack::GetNsignals()
+{
+// Provide the number of related AliSignals.
+ return fNsig;
+}
+///////////////////////////////////////////////////////////////////////////
+AliSignal* AliTrack::GetSignal(Int_t j)
+{
+// Provide the related AliSignal number j.
+// Note : j=1 denotes the first signal.
+ if ((j >= 1) && (j <= fNsig))
+ {
+ return (AliSignal*)fSignals->At(j-1);
+ }
+ else
+ {
+ cout << " *AliTrack* signal number : " << j << " out of range." << endl;
+ cout << " -- Signal number 1 (if any) returned." << endl;
+ return (AliSignal*)fDecays->At(0);
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::SetBeginPoint(AliPosition p)
+{
+// Store the position of the track begin-point.
+ fBegin=p;
+}
+///////////////////////////////////////////////////////////////////////////
+AliPosition AliTrack::GetBeginPoint()
+{
+// Provide the position of the track begin-point.
+ return fBegin;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::SetEndPoint(AliPosition p)
+{
+// Store the position of the track end-point.
+ fEnd=p;
+}
+///////////////////////////////////////////////////////////////////////////
+AliPosition AliTrack::GetEndPoint()
+{
+// Provide the position of the track end-point.
+ return fEnd;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::AddMassHypothesis(Double_t prob,Double_t m,Double_t dm)
+{
+// Add a mass hypothesis for this current track.
+// prob=probalility m=mass value dm=error on the mass value.
+// The default value for the mass error dm is 0.
+ if (!fMasses) fMasses=new TArrayD();
+ if (!fDmasses) fDmasses=new TArrayD();
+ if (!fPmasses) fPmasses=new TArrayD();
+
+ fNmasses++;
+ fMasses->Set(fNmasses);
+ fDmasses->Set(fNmasses);
+ fPmasses->Set(fNmasses);
+
+ fMasses->AddAt(m,fNmasses-1);
+ fDmasses->AddAt(dm,fNmasses-1);
+ fPmasses->AddAt(prob,fNmasses-1);
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliTrack::GetNMassHypotheses()
+{
+// Provide the number of mass hypotheses for this track.
+ return fNmasses;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetMassHypothesis(Int_t j)
+{
+// Provide the mass of the jth hypothesis for this track.
+// Note : the first hypothesis is indicated by j=1.
+// Default : j=0 ==> Hypothesis with highest probability.
+// The error on the mass can be obtained by invoking GetResultError()
+// after invokation of GetMassHypothesis(j).
+
+ Double_t m=0,dm=0,prob=0;
+
+ // Check validity of index j
+ if (j<0 || j>fNmasses)
+ {
+ cout << " *AliTrack::GetMassHypothesis* Invalid index j : " << j
+ << " Number of mass hypotheses : " << fNmasses << endl;
+ fDresult=0;
+ return 0;
+ }
+
+ // Select mass hypothesis with highest probability
+ if (j==0)
+ {
+ if (fNmasses)
+ {
+ m=fMasses->At(0);
+ dm=fDmasses->At(0);
+ prob=fPmasses->At(0);
+ for (Int_t i=1; i<fNmasses; i++)
+ {
+ if (fPmasses->At(i)>prob)
+ {
+ m=fMasses->At(i);
+ dm=fDmasses->At(i);
+ }
+ }
+ }
+ fDresult=dm;
+ return m;
+ }
+
+ // Provide data of requested mass hypothesis
+ m=fMasses->At(j-1);
+ fDresult=fDmasses->At(j-1);
+ return m;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetMassHypothesisProb(Int_t j)
+{
+// Provide the probability of the jth hypothesis for this track.
+// Note : the first hypothesis is indicated by j=1.
+// Default : j=0 ==> Hypothesis with highest probability.
+
+ Double_t prob=0;
+
+ // Check validity of index j
+ if (j<0 || j>fNmasses)
+ {
+ cout << " *AliTrack::GetMassHypothesisProb* Invalid index j : " << j
+ << " Number of mass hypotheses : " << fNmasses << endl;
+ return 0;
+ }
+
+ // Select mass hypothesis with highest probability
+ if (j==0)
+ {
+ if (fNmasses)
+ {
+ prob=fPmasses->At(0);
+ for (Int_t i=1; i<fNmasses; i++)
+ {
+ if (fPmasses->At(i)>prob) prob=fPmasses->At(i);
+ }
+ }
+ return prob;
+ }
+
+ // Provide probability of requested mass hypothesis
+ prob=fPmasses->At(j-1);
+ return prob;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::SetMass()
+{
+// Set the mass and error to the value of the hypothesis with highest prob.
+
+ Double_t m=0,dm=0,prob=0;
+
+ // Select mass hypothesis with highest probability
+ if (fNmasses)
+ {
+ m=fMasses->At(0);
+ dm=fDmasses->At(0);
+ prob=fPmasses->At(0);
+ for (Int_t i=1; i<fNmasses; i++)
+ {
+ if (fPmasses->At(i)>prob)
+ {
+ m=fMasses->At(i);
+ dm=fDmasses->At(i);
+ }
+ }
+ SetMass(m,dm);
+ }
+ else
+ {
+ cout << " *AliTrack::SetMass()* No hypothesis present => No action." << endl;
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::RemoveMassHypothesis(Int_t j)
+{
+// Remove the jth mass hypothesis for this track.
+// Note : the first hypothesis is indicated by j=1.
+
+ if (j<=0 || j>fNmasses) // Check validity of index j
+ {
+ cout << " *AliTrack::RemoveMassHypothesis* Invalid index j : " << j
+ << " Number of mass hypotheses : " << fNmasses << endl;
+ }
+ else
+ {
+ if (j != fNmasses)
+ {
+ fMasses->AddAt(fMasses->At(fNmasses-1),j-1);
+ fDmasses->AddAt(fDmasses->At(fNmasses-1),j-1);
+ fPmasses->AddAt(fPmasses->At(fNmasses-1),j-1);
+ }
+ fMasses->AddAt(0,fNmasses-1);
+ fDmasses->AddAt(0,fNmasses-1);
+ fPmasses->AddAt(0,fNmasses-1);
+ fNmasses--;
+ fMasses->Set(fNmasses);
+ fDmasses->Set(fNmasses);
+ fPmasses->Set(fNmasses);
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetPt()
+{
+// Provide trans. momentum value w.r.t. z-axis.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetPt().
+ Ali3Vector v;
+ v=GetVecTrans();
+ Double_t norm=v.GetNorm();
+ fDresult=v.GetResultError();
+
+ return norm;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetPl()
+{
+// Provide long. momentum value w.r.t. z-axis.
+// Note : the returned value can also be negative.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetPl().
+ Ali3Vector v;
+ v=GetVecLong();
+
+ Double_t pl=v.GetNorm();
+ fDresult=v.GetResultError();
+
+ Double_t a[3];
+ v.GetVector(a,"sph");
+ if (cos(a[1])<0) pl=-pl;
+
+ return pl;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetEt()
+{
+// Provide trans. energy value w.r.t. z-axis.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetEt().
+ Double_t et=GetScaTrans();
+
+ return et;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetEl()
+{
+// Provide long. energy value w.r.t. z-axis.
+// Note : the returned value can also be negative.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetEl().
+ Double_t el=GetScaLong();
+
+ return el;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetMt()
+{
+// Provide transverse mass value w.r.t. z-axis.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetMt().
+ Double_t pt=GetPt();
+ Double_t dpt=GetResultError();
+ Double_t m=GetMass();
+ Double_t dm=GetResultError();
+
+ Double_t mt=sqrt(pt*pt+m*m);
+ Double_t dmt2=0;
+ if (mt) dmt2=(pow((pt*dpt),2)+pow((m*dm),2))/(mt*mt);
+
+ fDresult=sqrt(dmt2);
+ return mt;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetMt(Int_t j)
+{
+// Provide transverse mass value w.r.t. z-axis and jth mass hypothesis.
+// Note : the first hypothesis is indicated by j=1.
+// j=0 ==> Hypothesis with highest probability.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetMt(j).
+ Double_t pt=GetPt();
+ Double_t dpt=GetResultError();
+ Double_t m=GetMassHypothesis(j);
+ Double_t dm=GetResultError();
+
+ Double_t mt=sqrt(pt*pt+m*m);
+ Double_t dmt2=0;
+ if (mt) dmt2=(pow((pt*dpt),2)+pow((m*dm),2))/(mt*mt);
+
+ fDresult=sqrt(dmt2);
+ return mt;
+}
+///////////////////////////////////////////////////////////////////////////
+Double_t AliTrack::GetRapidity()
+{
+// Provide rapidity value w.r.t. z-axis.
+// The error on the value can be obtained by GetResultError()
+// after invokation of GetRapidity().
+// Note : Also GetPseudoRapidity() is available since this class is
+// derived from Ali4Vector.
+ Double_t e=GetEnergy();
+ Double_t de=GetResultError();
+ Double_t pl=GetPl();
+ Double_t dpl=GetResultError();
+ Double_t sum=e+pl;
+ Double_t dif=e-pl;
+
+ Double_t y=9999,dy2=0;
+ if (sum && dif) y=0.5*log(sum/dif);
+
+ if (sum*dif) dy2=(1./(sum*dif))*(pow((pl*de),2)+pow((e*dpl),2));
+
+ fDresult=sqrt(dy2);
+ return y;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::SetImpactPoint(AliPosition p,TString q)
+{
+// Store the position of the impact-point in the plane "q=0".
+// Here q denotes one of the axes X, Y or Z.
+// Note : The character to denote the axis may be entered in lower or
+// in uppercase.
+ Int_t axis=0;
+ if (q=="x" || q=="X") axis=1;
+ if (q=="y" || q=="Y") axis=2;
+ if (q=="z" || q=="Z") axis=3;
+
+ switch (axis)
+ {
+ case 1: // Impact-point in the plane X=0
+ fImpactYZ=p;
+ break;
+
+ case 2: // Impact-point in the plane Y=0
+ fImpactXZ=p;
+ break;
+
+ case 3: // Impact-point in the plane Z=0
+ fImpactXY=p;
+ break;
+
+ default: // Unsupported axis
+ cout << "*AliTrack::SetImpactPoint* Unsupported axis : " << q << endl
+ << " Possible axes are 'X', 'Y' and 'Z'." << endl;
+ break;
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+AliPosition AliTrack::GetImpactPoint(TString q)
+{
+// Provide the position of the impact-point in the plane "q=0".
+// Here q denotes one of the axes X, Y or Z.
+// Note : The character to denote the axis may be entered in lower or
+// in uppercase.
+ AliPosition dummy;
+ Int_t axis=0;
+ if (q=="x" || q=="X") axis=1;
+ if (q=="y" || q=="Y") axis=2;
+ if (q=="z" || q=="Z") axis=3;
+
+ switch (axis)
+ {
+ case 1: // Impact-point in the plane X=0
+ return fImpactYZ;
+
+ case 2: // Impact-point in the plane Y=0
+ return fImpactXZ;
+
+ case 3: // Impact-point in the plane Z=0
+ return fImpactXY;
+
+ default: // Unsupported axis
+ cout << "*AliTrack::GetImpactPoint* Unsupported axis : " << q << endl
+ << " Possible axes are 'X', 'Y' and 'Z'." << endl;
+ return dummy;
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::SetId(Int_t id)
+{
+// Set a user defined identifier for this track.
+ fUserId=id;
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliTrack::GetId()
+{
+// Provide the user defined identifier of this track.
+ return fUserId;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliTrack::SetClosestPoint(AliPosition p)
+{
+// Set position p as the point of closest approach w.r.t. some reference
+ fClosest=p;
+}
+///////////////////////////////////////////////////////////////////////////
+AliPosition AliTrack::GetClosestPoint()
+{
+// Provide the point of closest approach w.r.t. some reference
+ return fClosest;
+}
+///////////////////////////////////////////////////////////////////////////
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff