CDCSZFitter Class Reference

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

#include <CDCSZFitter.h>

Static Public Member Functions
static const CDCSZFitter &	getFitter ()
	Getter for a standard sz line fitter instance.
static TrackingUtilities::CDCTrajectorySZ	fitWithStereoHits (const TrackingUtilities::CDCTrack &track)
	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.
static TrackingUtilities::CDCTrajectorySZ	fit (const TrackingUtilities::CDCSegment2D &stereoSegment, const TrackingUtilities::CDCTrajectory2D &axialTrajectory2D)
	Returns a fitted trajectory.
static TrackingUtilities::CDCTrajectorySZ	fit (const TrackingUtilities::CDCSegment3D &segment3D)
	Fits a linear sz trajectory to the z and s coordinates in the stereo segment.
static TrackingUtilities::CDCTrajectorySZ	fit (CDCSZObservations observationsSZ)
	Fits a linear sz trajectory to the s and z coordinates given in the observations.
static TrackingUtilities::CDCTrajectorySZ	fit (const CDCObservations2D &observations2D)
	Legacy - Fits a linear sz trajectory to the x and y coordinates interpreted as sz space.
static void	update (const TrackingUtilities::CDCSegmentPair &segmentPair)
	Updates the trajectory of the axial stereo segment pair inplace.
static void	update (TrackingUtilities::CDCTrajectorySZ &trajectorySZ, const TrackingUtilities::CDCSegment2D &stereoSegment, const TrackingUtilities::CDCTrajectory2D &axialTrajectory2D)
	Update the given sz trajectory reconstructing the stereo segment with a near by axial segment.
static void	update (TrackingUtilities::CDCTrajectorySZ &trajectorySZ, CDCSZObservations &observationsSZ)
	Update the trajectory with a fit to the observations.

Detailed Description

Class implementing the z coordinate over travel distance line fit.

Definition at line 29 of file CDCSZFitter.h.

Member Function Documentation

fit() [1/4]

CDCTrajectorySZ fit ( CDCSZObservations observationsSZ )

static

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 )

static

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 TrackingUtilities::CDCSegment2D & stereoSegment, const TrackingUtilities::CDCTrajectory2D & axialTrajectory2D )

static

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 TrackingUtilities::CDCSegment3D & segment3D )

static

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 TrackingUtilities::CDCTrack & track )

static

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 37 of file CDCSZFitter.cc.

{
  static CDCSZFitter szFitter;
  return szFitter;
}

update() [1/3]

void update ( const TrackingUtilities::CDCSegmentPair & segmentPair )

static

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);
}

update() [2/3]

void update ( TrackingUtilities::CDCTrajectorySZ & trajectorySZ, CDCSZObservations & observationsSZ )

static

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() [3/3]

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

static

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);
}

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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