CDCSZFitter Class Reference

Class implementing the z coordinate over travel distance line fit. More...

#include <CDCSZFitter.h>

Public Member Functions
CDCTrajectorySZ	fitWithStereoHits (const CDCTrack &track) const
	Returns the fitted sz trajectory of the track with the z-information of all stereo hits of the number of stereo hits is big enough.
CDCTrajectorySZ	fit (const CDCSegment2D &stereoSegment, const CDCTrajectory2D &axialTrajectory2D) const
	Returns a fitted trajectory.
CDCTrajectorySZ	fit (const CDCSegment3D &segment3D) const
	Fits a linear sz trajectory to the z and s coordinates in the stereo segment.
CDCTrajectorySZ	fit (CDCSZObservations observationsSZ) const
	Fits a linear sz trajectory to the s and z coordinates given in the observations.
CDCTrajectorySZ	fit (const CDCObservations2D &observations2D) const
	Legacy - Fits a linear sz trajectory to the x and y coordinates interpreted as sz space.
void	update (const CDCSegmentPair &segmentPair) const
	Updates the trajectory of the axial stereo segment pair inplace.
void	update (CDCTrajectorySZ &trajectorySZ, const CDCSegment2D &stereoSegment, const CDCTrajectory2D &axialTrajectory2D) const
	Update the given sz trajectory reconstructing the stereo segment with a near by axial segment.
void	update (CDCTrajectorySZ &trajectorySZ, CDCSZObservations &observationsSZ) const
	Update the trajectory with a fit to the observations.

Static Public Member Functions
static const CDCSZFitter &	getFitter ()
	Getter for a standard sz line fitter instance.

Detailed Description

Class implementing the z coordinate over travel distance line fit.

Definition at line 27 of file CDCSZFitter.h.

Member Function Documentation

fit() [1/4]

CDCTrajectorySZ fit

(

CDCSZObservations

observationsSZ

)

const

Fits a linear sz trajectory to the s and z coordinates given in the observations.

Definition at line 156 of file CDCSZFitter.cc.

{
  CDCTrajectorySZ trajectorySZ;
  update(trajectorySZ, observationsSZ);
  return trajectorySZ;
}

fit() [2/4]

CDCTrajectorySZ fit

(

const CDCObservations2D &

observations2D

)

const

Legacy - Fits a linear sz trajectory to the x and y coordinates interpreted as sz space.

Definition at line 182 of file CDCSZFitter.cc.

{
  CDCSZObservations szObservations;
  for (size_t i = 0; i < observations2D.size(); ++i) {
    const double s = observations2D.getX(i);
    const double z = observations2D.getY(i);
    szObservations.fill(s, z);
  }
  return fit(std::move(szObservations));
}

fit() [3/4]

CDCTrajectorySZ fit	(	const CDCSegment2D &	stereoSegment,
		const CDCTrajectory2D &	axialTrajectory2D
	)		const

Returns a fitted trajectory.

Definition at line 139 of file CDCSZFitter.cc.

{
  B2ASSERT("Expected stereo segment", not stereoSegment.isAxial());
 
  CDCTrajectorySZ trajectorySZ;
  update(trajectorySZ, stereoSegment, axialTrajectory2D);
  return trajectorySZ;
}

fit() [4/4]

CDCTrajectorySZ fit

(

const CDCSegment3D &

segment3D

)

const

Fits a linear sz trajectory to the z and s coordinates in the stereo segment.

Definition at line 149 of file CDCSZFitter.cc.

{
  CDCSZObservations observationsSZ;
  observationsSZ.appendRange(segment3D);
  return fit(std::move(observationsSZ));
}

fitWithStereoHits()

CDCTrajectorySZ fitWithStereoHits

(

const CDCTrack &

track

)

const

Returns the fitted sz trajectory of the track with the z-information of all stereo hits of the number of stereo hits is big enough.

Else return the basic assumption.

Definition at line 125 of file CDCSZFitter.cc.

{
  const bool onlyStereo = true;
  CDCSZObservations observationsSZ(EFitVariance::c_Proper, onlyStereo);
  observationsSZ.appendRange(track);
  if (observationsSZ.size() > 3) {
    CDCTrajectorySZ szTrajectory;
    update(szTrajectory, observationsSZ);
    return szTrajectory;
  } else {
    return CDCTrajectorySZ::basicAssumption();
  }
}

getFitter()

const CDCSZFitter & getFitter ( )

static

Getter for a standard sz line fitter instance.

Definition at line 36 of file CDCSZFitter.cc.

{
  static CDCSZFitter szFitter;
  return szFitter;
}

update() [1/3]

void update	(	CDCTrajectorySZ &	trajectorySZ,
		CDCSZObservations &	observationsSZ
	)		const

Update the trajectory with a fit to the observations.

Definition at line 209 of file CDCSZFitter.cc.

{
  trajectorySZ.clear();
  if (observationsSZ.size() < 3) {
    return;
  }
 
  // Determine NDF : Line fit eats up 2 degrees of freedom.
  size_t ndf = observationsSZ.size() - 2;
 
  // Matrix of weighted sums
  Eigen::Matrix<double, 3, 3> sumMatrixWSZ = getWSZSumMatrix(observationsSZ);
  UncertainSZLine uncertainSZLine = fitZ(sumMatrixWSZ);
 
  uncertainSZLine.setNDF(ndf);
  trajectorySZ.setSZLine(uncertainSZLine);
}

update() [2/3]

void update	(	CDCTrajectorySZ &	trajectorySZ,
		const CDCSegment2D &	stereoSegment,
		const CDCTrajectory2D &	axialTrajectory2D
	)		const

Update the given sz trajectory reconstructing the stereo segment with a near by axial segment.

Definition at line 193 of file CDCSZFitter.cc.

{
  B2ASSERT("Expected stereo segment", not stereoSegment.isAxial());
 
  // recostruct the stereo segment
  CDCSZObservations observationsSZ;
  for (const CDCRecoHit2D& recoHit2D : stereoSegment) {
    CDCRecoHit3D recoHit3D = CDCRecoHit3D::reconstruct(recoHit2D, axialTrajectory2D);
    observationsSZ.append(recoHit3D);
  }
 
  update(trajectorySZ, observationsSZ);
}

update() [3/3]

void update

(

const CDCSegmentPair &

segmentPair

)

const

Updates the trajectory of the axial stereo segment pair inplace.

Definition at line 163 of file CDCSZFitter.cc.

{
  const CDCSegment2D* ptrStereoSegment = segmentPair.getStereoSegment();
  const CDCSegment2D* ptrAxialSegment = segmentPair.getAxialSegment();
 
  assert(ptrStereoSegment);
  assert(ptrAxialSegment);
 
  const CDCSegment2D& stereoSegment = *ptrStereoSegment;
  const CDCSegment2D& axialSegment = *ptrAxialSegment;
  const CDCTrajectory2D& axialTrajectory2D = axialSegment.getTrajectory2D();
 
  CDCTrajectorySZ trajectorySZ;
  update(trajectorySZ, stereoSegment, axialTrajectory2D);
 
  CDCTrajectory3D trajectory3D(axialTrajectory2D, trajectorySZ);
  segmentPair.setTrajectory3D(trajectory3D);
}

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

• tracking/trackFindingCDC/fitting/include/CDCSZFitter.h
• tracking/trackFindingCDC/fitting/src/CDCSZFitter.cc