Chi2StripEstimator Class Reference

#include <Chi2StripEstimator.h>

Inheritance diagram for Chi2StripEstimator:

Public Member Functions
	Chi2StripEstimator (double maxChi2, double nSigma=3.)
virtual Chi2StripEstimator *	clone () const
virtual std::pair< bool, double >	estimate (const TrajectoryStateOnSurface &, const TransientTrackingRecHit &) const
Public Member Functions inherited from Chi2MeasurementEstimatorBase
	Chi2MeasurementEstimatorBase (double maxChi2, double nSigma=3.)
double	chiSquaredCut () const
virtual bool	estimate (const TrajectoryStateOnSurface &ts, const BoundPlane &plane) const
virtual Local2DVector	maximalLocalDisplacement (const TrajectoryStateOnSurface &ts, const BoundPlane &plane) const
double	nSigmaCut () const
Public Member Functions inherited from MeasurementEstimator
virtual	~MeasurementEstimator ()

Additional Inherited Members
Public Types inherited from MeasurementEstimator
typedef std::pair< bool, double >	HitReturnType
typedef Vector2DBase< float, LocalTag >	Local2DVector
typedef bool	SurfaceReturnType
Protected Member Functions inherited from Chi2MeasurementEstimatorBase
std::pair< bool, double >	returnIt (double est) const

Detailed Description

A Chi2 MeasurementEstimator that works in the measurement (strip) frame and uses both coordinates of a hit. Ported from ORCA.

Date:

2007/05/09 14:05:13

Revision:

1.2

Author

todorov, cerati

Definition at line 15 of file Chi2StripEstimator.h.

Constructor & Destructor Documentation

Chi2StripEstimator::Chi2StripEstimator ( double  maxChi2, double  nSigma = 3.  )

inlineexplicit

Definition at line 18 of file Chi2StripEstimator.h.

Referenced by clone().

                                                                  : 
    Chi2MeasurementEstimatorBase( maxChi2, nSigma) {}

Member Function Documentation

virtual Chi2StripEstimator* Chi2StripEstimator::clone ( void  ) const

inlinevirtual

Implements MeasurementEstimator.

Definition at line 24 of file Chi2StripEstimator.h.

References Chi2StripEstimator().

                                            {
    return new Chi2StripEstimator(*this);
  }

pair< bool, double > Chi2StripEstimator::estimate ( const TrajectoryStateOnSurface &  ts, const TransientTrackingRecHit &  hit  ) const

virtual

Returns pair( true, value) if the TrajectoryStateOnSurface is compatible with the RecHit, and pair( false, value) if it is not compatible. The TrajectoryStateOnSurface must be on the same Surface as the RecHit. For an estimator where there is no value computed, e.g. fixed window estimator, only the first(bool) part is of interest.

Implements Chi2MeasurementEstimatorBase.

Definition at line 11 of file Chi2StripEstimator.cc.

References funct::C, TransientTrackingRecHit::detUnit(), invertPosDefMatrix(), GeomDetType::isTrackerPixel(), TrajectoryStateOnSurface::localError(), TrackingRecHit::localPosition(), TrajectoryStateOnSurface::localPosition(), TrackingRecHit::localPositionError(), m, max(), Topology::measurementError(), Topology::measurementPosition(), LocalTrajectoryError::positionError(), dttmaxenums::R, alignCSCRings::r, GeomDetUnit::topology(), GeomDetUnit::type(), MeasurementError::uu(), MeasurementError::uv(), MeasurementError::vv(), PV2DBase< T, PVType, FrameType >::x(), vdt::x, and PV2DBase< T, PVType, FrameType >::y().

Referenced by Chi2SwitchingEstimator::estimate().

                                                           {

  if(//hit.isMatched() || 
     hit.detUnit()->type().isTrackerPixel()) {
    return HitReturnType(false,0);
  }

  const StripTopology* topology = 
    dynamic_cast<const StripTopology*>(&(hit.detUnit()->topology())); 

  MeasurementPoint mp;
  MeasurementError me;

  AlgebraicVector2 m;
  mp = topology->measurementPosition(hit.localPosition());
  m[0] = mp.x();
  m[1] = mp.y();
  
  AlgebraicSymMatrix22 V;
  me = topology->measurementError(hit.localPosition(),
                  hit.localPositionError());
 
  V(0,0) = me.uu();
  V(1,0) = me.uv();
  V(1,1) = me.vv();

  AlgebraicVector2 x;
  mp = topology->measurementPosition(state.localPosition());
  m[0] = mp.x();
  m[1] = mp.y();
  
  AlgebraicSymMatrix22 C;
  me = topology->measurementError(state.localPosition(),
                  state.localError().positionError());
  C(0,0) = me.uu();
  C(1,0) = me.uv();
  C(1,1) = me.vv();

  AlgebraicVector2 r(m - x);
  AlgebraicSymMatrix22 R(V+C);
  bool ierr =  !invertPosDefMatrix(R);
  if (ierr) {
    edm::LogError("Chi2StripEstimator")<<" could not invert matrix:\n"<<(V+C);
    return returnIt( 0.0 );
  }

  double est = max(ROOT::Math::Similarity(r, R), 0.000001); // avoid exact zero

  return returnIt( est);
}