AliKFVertex Class Reference

#include <AliKFVertex.h>

Inheritance diagram for AliKFVertex:

Public Member Functions
	AliKFVertex ()
	~AliKFVertex ()
	AliKFVertex (const KFPVertex &vertex)
Int_t	GetNContributors () const
void	operator+= (const AliKFParticle &Daughter)
AliKFVertex	operator- (const AliKFParticle &Daughter) const
void	operator-= (const AliKFParticle &Daughter)
void	SetBeamConstraint (float X, float Y, float Z, float ErrX, float ErrY, float ErrZ)
void	SetBeamConstraintOff ()
void	ConstructPrimaryVertex (const AliKFParticle *vDaughters[], int NDaughters, Bool_t vtxFlag[], float ChiCut=3.5)

Protected Attributes
Bool_t	fIsConstrained

Detailed Description

Definition at line 24 of file AliKFVertex.h.

Constructor & Destructor Documentation

AliKFVertex::AliKFVertex ( )

inline

Definition at line 35 of file AliKFVertex.h.

:AliKFParticle(),fIsConstrained(0){ } 

AliKFVertex::~AliKFVertex ( )

inline

Definition at line 39 of file AliKFVertex.h.

{}

AliKFVertex::AliKFVertex

(

const KFPVertex &

vertex

)

Definition at line 22 of file AliKFVertex.cxx.

References KFPVertex::GetChi2(), KFPVertex::GetCovarianceMatrix(), KFPVertex::GetNContributors(), and KFPVertex::GetXYZ().

                                                 : fIsConstrained(0)
{
  // Constructor from ALICE VVertex

  vertex.GetXYZ( fP );
  vertex.GetCovarianceMatrix( fC );  
  fChi2 = vertex.GetChi2();  
  fNDF = 2*vertex.GetNContributors() - 3;
  fQ = 0;
  fAtProductionVertex = 0;
  fIsLinearized = 0;
  fSFromDecay = 0;
}

Member Function Documentation

void AliKFVertex::ConstructPrimaryVertex	(	const AliKFParticle *	vDaughters[],
		int	NDaughters,
		Bool_t	vtxFlag[],
		float	ChiCut = 3.5
	)

Definition at line 67 of file AliKFVertex.cxx.

References fIsConstrained, i, and p.

{
  //* Primary vertex finder with simple rejection of outliers

  if( NDaughters<2 ) return;
  float constrP[3]={fP[0], fP[1], fP[2]};
  float constrC[6]={fC[0], fC[1], fC[2], fC[3], fC[4], fC[5]};

  Construct( vDaughters, NDaughters, 0, -1, fIsConstrained );

  SetVtxGuess( fVtxGuess[0], fVtxGuess[1], fVtxGuess[2] );

  for( int i=0; i<NDaughters; i++ ) vtxFlag[i] = 1;

  Int_t nRest = NDaughters;
  while( nRest>2 )
  {    
    float worstChi = 0.;
    Int_t worstDaughter = 0;
    for( Int_t it=0; it<NDaughters; it++ ){
      if( !vtxFlag[it] ) continue;      
      const AliKFParticle &p = *(vDaughters[it]);
      AliKFVertex tmp = *this - p;
      float chi = p.GetDeviationFromVertex( tmp );      
      if( worstChi < chi ){
        worstChi = chi;
        worstDaughter = it;
      }
    }
    if( worstChi < ChiCut ) break;
      
    vtxFlag[worstDaughter] = 0;    
    *this -= *(vDaughters[worstDaughter]);
    nRest--;
  } 

  if( nRest>=2 ) {// final refit     
    SetVtxGuess( fP[0], fP[1], fP[2] );
    if( fIsConstrained ){
      fP[0] = constrP[0];
      fP[1] = constrP[1];
      fP[2] = constrP[2];
      for( int i=0; i<6; i++ ) fC[i] = constrC[i];
    }
    int nDaughtersNew=0;
    const AliKFParticle **vDaughtersNew=new const AliKFParticle *[NDaughters];
    for( int i=0; i<NDaughters; i++ ){
      if( vtxFlag[i] )  vDaughtersNew[nDaughtersNew++] = vDaughters[i];
    }
    Construct( vDaughtersNew, nDaughtersNew, 0, -1, fIsConstrained );
    delete[] vDaughtersNew;
  }

  if( nRest<=2 && GetChi2() > ChiCut*ChiCut*GetNDF() ) {
    for( int i=0; i<NDaughters; i++ ) vtxFlag[i] = 0;
    fNDF = -3;
    fChi2 = 0;
  }
}

Int_t AliKFVertex::GetNContributors ( ) const

inline

Definition at line 52 of file AliKFVertex.h.

References fIsConstrained.

{ return fIsConstrained ?fNDF/2:(fNDF+3)/2; }

void AliKFVertex::operator+= ( const AliKFParticle &  Daughter )

inline

Definition at line 98 of file AliKFVertex.h.

References operator+=().

{
  AliKFParticle::operator+=( Daughter );
}

AliKFVertex AliKFVertex::operator- ( const AliKFParticle &  Daughter ) const

inline

Definition at line 109 of file AliKFVertex.h.

{
  AliKFVertex tmp = *this;
  Daughter.SubtractFromVertex( tmp );
  return tmp;
}

void AliKFVertex::operator-= ( const AliKFParticle &  Daughter )

inline

Definition at line 104 of file AliKFVertex.h.

{
  Daughter.SubtractFromVertex( *this );
}

void AliKFVertex::SetBeamConstraint	(	float	X,
		float	Y,
		float	Z,
		float	ErrX,
		float	ErrY,
		float	ErrZ
	)

Definition at line 46 of file AliKFVertex.cxx.

References fIsConstrained, x, y, and z.

{
  // Set beam constraint to the vertex
  fP[0] = x;
  fP[1] = y;
  fP[2] = z;
  fC[0] = errX*errX;
  fC[1] = 0;
  fC[2] = errY*errY;
  fC[3] = 0;
  fC[4] = 0;
  fC[5] = errZ*errZ;
  fIsConstrained = 1;
}

void AliKFVertex::SetBeamConstraintOff

(

)

Definition at line 62 of file AliKFVertex.cxx.

References fIsConstrained.

{
  fIsConstrained = 0;
}

Member Data Documentation

Bool_t AliKFVertex::fIsConstrained

protected

Definition at line 86 of file AliKFVertex.h.

Referenced by ConstructPrimaryVertex(), GetNContributors(), SetBeamConstraint(), and SetBeamConstraintOff().

---

The documentation for this class was generated from the following files:

• AliKFVertex.h
• AliKFVertex.cxx