VertexDistanceXY Class Reference

#include <VertexDistanceXY.h>

Inheritance diagram for VertexDistanceXY:

Public Member Functions
VertexDistanceXY *	clone () const override
Measurement1D	signedDistance (const reco::Vertex &primVtx, const reco::Vertex &secVtx, const GlobalVector &momentum) const override
	VertexDistanceXY ()
Public Member Functions inherited from VertexDistance
virtual float	compatibility (const reco::Vertex &, const reco::Vertex &) const
virtual float	compatibility (const VertexState &, const VertexState &) const
virtual float	compatibility (const reco::Vertex &, const VertexState &) const
virtual float	compatibility (const VertexState &, const reco::Vertex &) const
Measurement1D	distance (const reco::Vertex &, const reco::Vertex &) const
Measurement1D	distance (const VertexState &, const VertexState &) const
Measurement1D	distance (const reco::Vertex &, const VertexState &) const
Measurement1D	distance (const VertexState &, const reco::Vertex &) const
virtual	~VertexDistance ()

Private Member Functions
float	compatibility (const GlobalPoint &vtx1Position, const GlobalError &vtx1PositionError, const GlobalPoint &vtx2Position, const GlobalError &vtx2PositionError) const override
Measurement1D	distance (const GlobalPoint &vtx1Position, const GlobalError &vtx1PositionError, const GlobalPoint &vtx2Position, const GlobalError &vtx2PositionError) const override

Private Attributes
AlgebraicSymMatrix22	theNullMatrix

Additional Inherited Members

Detailed Description

Computes the distance between two vertices as the chi-squared formed with their positions in the transverse plane.

Definition at line 11 of file VertexDistanceXY.h.

Constructor & Destructor Documentation

VertexDistanceXY::VertexDistanceXY ( )

inline

Definition at line 13 of file VertexDistanceXY.h.

Referenced by clone().

{}

Member Function Documentation

VertexDistanceXY* VertexDistanceXY::clone ( void  ) const

inlineoverridevirtual

Implements VertexDistance.

Definition at line 27 of file VertexDistanceXY.h.

References VertexDistanceXY().

{ return new VertexDistanceXY(*this); }

float VertexDistanceXY::compatibility ( const GlobalPoint &  vtx1Position, const GlobalError &  vtx1PositionError, const GlobalPoint &  vtx2Position, const GlobalError &  vtx2PositionError  ) const

overrideprivatevirtual

Implements VertexDistance.

Definition at line 40 of file VertexDistanceXY.cc.

References change_name::diff, relativeConstraints::error, Exception, GlobalErrorBase< T, ErrorWeightType >::matrix(), PV3DBase< T, PVType, FrameType >::x(), and PV3DBase< T, PVType, FrameType >::y().

                                                                                  {
  // error matrix of residuals
  AlgebraicSymMatrix33 err1 = vtx1PositionError.matrix();
  AlgebraicSymMatrix33 err2 = vtx2PositionError.matrix();
  AlgebraicSymMatrix22 error;
  error[0][0] = err1[0][0] + err2[0][0];
  error[0][1] = err1[0][1] + err2[0][1];
  error[1][1] = err1[1][1] + err2[1][1];
  if (error == theNullMatrix)
    return FLT_MAX;

  // position residuals
  GlobalVector diff = vtx2Position - vtx1Position;
  AlgebraicVector2 vDiff;
  vDiff[0] = diff.x();
  vDiff[1] = diff.y();

  // Invert error matrix of residuals
  bool ifail = !error.Invert();
  if (ifail) {
    throw cms::Exception("VertexDistanceXY::matrix inversion problem");
  }

  return ROOT::Math::Similarity(error, vDiff);
}

Measurement1D VertexDistanceXY::distance ( const GlobalPoint &  vtx1Position, const GlobalError &  vtx1PositionError, const GlobalPoint &  vtx2Position, const GlobalError &  vtx2PositionError  ) const

overrideprivatevirtual

Implements VertexDistance.

Definition at line 19 of file VertexDistanceXY.cc.

References change_name::diff, submitPVValidationJobs::err, relativeConstraints::error, GlobalErrorBase< T, ErrorWeightType >::matrix(), funct::pow(), mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), and PV3DBase< T, PVType, FrameType >::y().

Referenced by DiMuonVertexValidation::analyze(), VertexAnalysis::dist2D(), Onia2MuMuPAT::produce(), and btagbtvdeep::vertexDxy().

                                                                                     {
  AlgebraicSymMatrix33 error = vtx1PositionError.matrix() + vtx2PositionError.matrix();
  GlobalVector diff = vtx1Position - vtx2Position;
  AlgebraicVector3 vDiff;
  vDiff[0] = diff.x();
  vDiff[1] = diff.y();
  vDiff[2] = 0.;

  double dist = sqrt(pow(diff.x(), 2) + pow(diff.y(), 2));

  double err2 = ROOT::Math::Similarity(error, vDiff);
  double err = 0;
  if (dist != 0)
    err = sqrt(err2) / dist;

  return Measurement1D(dist, err);
}

Measurement1D VertexDistanceXY::signedDistance ( const reco::Vertex &  primVtx, const reco::Vertex &  secVtx, const GlobalVector &  momentum  ) const

overridevirtual

The signed distance is computed using a vector from the primary to the secondary vertex and a given reference vector. The sign is determined by the scalar product of the x,y component of the vector connecting the vertices and the reference vector: if the scalar product is greater than zero, the sign is +1, else -1

Implements VertexDistance.

Definition at line 9 of file VertexDistanceXY.cc.

References change_name::diff, HLT_FULL_cff::distance, Measurement1D::error(), reco::Vertex::position(), Measurement1D::value(), PV3DBase< T, PVType, FrameType >::x(), Basic3DVector< T >::x(), PV3DBase< T, PVType, FrameType >::y(), and Basic3DVector< T >::y().

                                                                                   {
  Measurement1D unsignedDistance = distance(vtx1, vtx2);
  Basic3DVector<float> diff = Basic3DVector<float>(vtx2.position()) - Basic3DVector<float>(vtx1.position());
  if ((momentum.x() * diff.x() + momentum.y() * diff.y()) < 0)
    return Measurement1D(-1.0 * unsignedDistance.value(), unsignedDistance.error());
  return unsignedDistance;
}

Member Data Documentation

AlgebraicSymMatrix22 VertexDistanceXY::theNullMatrix

private

Definition at line 33 of file VertexDistanceXY.h.