CDCRecoHit2D Class Reference

Class representing a two dimensional reconstructed hit in the central drift chamber. More...

#include <CDCRecoHit2D.h>

Public Member Functions
	CDCRecoHit2D ()=default
	Default constructor for ROOT.
	CDCRecoHit2D (const CDCRLWireHit &rlWireHit, const Vector2D &recoDisp2D)
	Constructs a reconstructed hit based on the given oriented wire hit with the given displacement from the wire reference position.
	CDCRecoHit2D (const CDCRLWireHit &rlWireHit)
	Constructs a reconstructed hit based on the oriented wire hit with no displacement.
void	reverse ()
	Turns the orientation in place.
CDCRecoHit2D	reversed () const
	Returns the recohit with the opposite right left information.
CDCRecoHit2D	getAlias () const
	Getter for the alias version of the reco hit.
	operator const Belle2::CDCHit * () const
	Make the wire hit automatically castable to its underlying cdcHit.
bool	operator== (const CDCRecoHit2D &other) const
	Equality comparison based on the oriented wire hit and displacement.
bool	operator< (const CDCRecoHit2D &other) const
	Total ordering relation based on wire hit, left right passage information and displacement in this order of importance.
CDC::EStereoKind	getStereoKind () const
	Getter for the stereo type of the underlying wire.
bool	isAxial () const
	Indicator if the underlying wire is axial.
CDC::ISuperLayer	getISuperLayer () const
	Getter for the superlayer id.
const CDC::CDCWire &	getWire () const
	Getter for the wire the reconstructed hit associated to.
const ROOT::Math::XYVector &	getRefPos2D () const
	Getter for the reference position of the wire.
bool	isOnWire (const CDC::CDCWire &wire) const
	Checks if the reconstructed hit is associated with the give wire.
const CDCWireHit &	getWireHit () const
	Getter for the wire hit associated with the reconstructed hit.
bool	hasWireHit (const CDCWireHit &wireHit) const
	Checks if the reconstructed hit is associated with the give wire hit.
ERightLeft	getRLInfo () const
	Getter for the right left passage information.
void	setRLInfo (ERightLeft &rlInfo)
	Setter the right left passage information.
double	getRefDriftLength () const
	Getter for the drift length at the wire reference position.
void	setRefDriftLength (double driftLength, bool snapRecoPos)
	Setter for the drift length at the wire reference position.
double	getSignedRefDriftLength () const
	Getter for the drift length at the wire reference position signed with the right left passage hypotheses.
double	getRefDriftLengthVariance () const
	Getter for the uncertainty in the drift length at the wire reference position.
Vector2D	getRecoPos2D () const
	Getter for the position in the reference plane.
void	setRecoPos2D (const Vector2D &recoPos2D)
	Setter for the position in the reference plane.
const Vector2D &	getRecoDisp2D () const
	Getter for the displacement from the wire reference position.
Vector2D	getFlightDirection2D () const
	Getter for the direction of flight.
double	getAlpha () const
	Getter for the direction of flight relative to the position.
void	snapToDriftCircle (bool switchSide=false)
	Scales the displacement vector in place to lie on the drift circle.
Vector3D	reconstruct3D (const CDCTrajectory2D &trajectory2D, const double z=0) const
	Reconstruct the three dimensional position (especially of stereo hits) by determining the z coordinate such that the reconstructed position lies on the given two dimensional trajectory as the reference reconstructed position is moved parallel to the stereo wire.
const CDCRLWireHit &	getRLWireHit () const
	Getter for the oriented wire hit associated with the reconstructed hit.
void	setRLWireHit (const CDCRLWireHit &rlWireHit)
	Setter for the oriented wire hit associated with the reconstructed hit.

Static Public Member Functions
static CDCRecoHit2D	average (const CDCRecoHit2D &recoHit1, const CDCRecoHit2D &recoHit2)
	Constructs the average of two reconstructed hit positions and snaps it to the drift circle.
static CDCRecoHit2D	average (const CDCRecoHit2D &recoHit1, const CDCRecoHit2D &recoHit2, const CDCRecoHit2D &recoHit3)
	Constructs the average of three reconstructed hit positions and snaps it to the drift circle.
static CDCRecoHit2D	fromRecoPos2D (const CDCRLWireHit &rlWireHit, const Vector2D &recoPos2D, bool snap=true)
	Constructs a two dimensional reconstructed hit from an absolute position.
static CDCRecoHit2D	fromSimHit (const CDCWireHit *wireHit, const CDCSimHit &simHit)
	Constructs a two dimensional reconstructed hit from a sim hit and the associated wirehit.

Private Attributes
CDCRLWireHit	m_rlWireHit
	Memory for the reference to the associated wire hit.
Vector2D	m_recoDisp2D
	Memory for the displacement of the associated wire reference position.

Friends
bool	operator< (const CDCRecoHit2D &recoHit2D, const CDC::CDCWire &wire)
	Defines wires and the two dimensional reconstructed hits as coaligned.
bool	operator< (const CDC::CDCWire &wire, const CDCRecoHit2D &recoHit2D)
	Defines wires and the two dimensional reconstructed hits as coaligned.
bool	operator< (const CDCRecoHit2D &recoHit2D, const CDCWireHit &wireHit)
	Defines wire hits and the two dimensional reconstructed hits as coaligned.
bool	operator< (const CDCWireHit &wireHit, const CDCRecoHit2D &recoHit2D)
	Defines wire hits and the two dimensional reconstructed hits as coaligned.

Detailed Description

Class representing a two dimensional reconstructed hit in the central drift chamber.

A recohit represents a likely point where the particle went through. It is always associated with a wire hit it seeks to reconstruct. The reconstructed point is stored as a displacement from the wire reference position associated with the hit. The displacement generally is as long as the drift length but must not.
In addition the reconstructed hit takes a right left passage information which indicates if the hit wire lies to the right or to the left of the particle trajectory causing the hit. The later readily indicates a flight direction from the reconstructed hit, if a tangential approach of the trajectory to the drift circle is assumed.

Definition at line 50 of file CDCRecoHit2D.h.

Constructor & Destructor Documentation

CDCRecoHit2D() [1/2]

CDCRecoHit2D	(	const CDCRLWireHit &	rlWireHit,
		const Vector2D &	recoDisp2D )

Constructs a reconstructed hit based on the given oriented wire hit with the given displacement from the wire reference position.

Definition at line 29 of file CDCRecoHit2D.cc.

                                                       :
  m_rlWireHit(rlWireHit),
  m_recoDisp2D(recoDisp2D)
{}

CDCRecoHit2D() [2/2]

CDCRecoHit2D ( const CDCRLWireHit & rlWireHit )

explicit

Constructs a reconstructed hit based on the oriented wire hit with no displacement.

Definition at line 24 of file CDCRecoHit2D.cc.

                                                        :
  m_rlWireHit(rlWireHit),
  m_recoDisp2D(Vector2D::getLowest())
{}

Member Function Documentation

average() [1/2]

CDCRecoHit2D average ( const CDCRecoHit2D & recoHit1, const CDCRecoHit2D & recoHit2 )

static

Constructs the average of two reconstructed hit positions and snaps it to the drift circle.

Averages the hit positions first. But the result will not lie on the circle, so we scale the displacement to snap onto the drift circle again. The function averages only reconstructed hits associated with the same right left oriented wire hit.
If not all reconstructed hits are on the same wire hit, the first hit is used.

Definition at line 47 of file CDCRecoHit2D.cc.

{
  CDCRLWireHit rlWireHit =
    CDCRLWireHit::average(recoHit1.getRLWireHit(),
                          recoHit2.getRLWireHit());
 
  Vector2D displacement =
    Vector2D::average(recoHit1.getRecoDisp2D(),
                      recoHit2.getRecoDisp2D());
 
  CDCRecoHit2D result(rlWireHit, displacement);
  result.snapToDriftCircle();
 
  return result;
}

average() [2/2]

CDCRecoHit2D average ( const CDCRecoHit2D & recoHit1, const CDCRecoHit2D & recoHit2, const CDCRecoHit2D & recoHit3 )

static

Constructs the average of three reconstructed hit positions and snaps it to the drift circle.

Averages the hit positions first. But the result will not lie on the circle, so we scale the displacement to snap onto the drift circle again. The function averages only reconstructed hits associated with the same wire hit.
If not all reconstructed hits are on the same wire, the first hit is used.

Definition at line 64 of file CDCRecoHit2D.cc.

{
  CDCRLWireHit rlWireHit =
    CDCRLWireHit::average(recoHit1.getRLWireHit(),
                          recoHit2.getRLWireHit(),
                          recoHit3.getRLWireHit());
 
  Vector2D displacement =
    Vector2D::average(recoHit1.getRecoDisp2D(),
                      recoHit2.getRecoDisp2D(),
                      recoHit3.getRecoDisp2D());
 
  CDCRecoHit2D result(rlWireHit, displacement);
  result.snapToDriftCircle();
 
  return result;
}

fromRecoPos2D()

CDCRecoHit2D fromRecoPos2D ( const CDCRLWireHit & rlWireHit, const Vector2D & recoPos2D, bool snap = true )

static

Constructs a two dimensional reconstructed hit from an absolute position.

Parameters

rlWireHit	the oriented wire hit the reconstructed hit is associated to
recoPos2D	the absolute position of the wire
snap	optional indicator if the displacement shall be shrank to the drift circle (default true)

Definition at line 84 of file CDCRecoHit2D.cc.

{
  CDCRecoHit2D result(rlWireHit, recoPos2D - rlWireHit.getRefPos2D());
  if (snap) result.snapToDriftCircle();
  return result;
}

fromSimHit()

CDCRecoHit2D fromSimHit ( const CDCWireHit * wireHit, const CDCSimHit & simHit )

static

Constructs a two dimensional reconstructed hit from a sim hit and the associated wirehit.

This translates the sim hit to a reconstructed hit mainly to be able to compare the reconstructed values from the algorithm with the Monte Carlo information. It merely takes the displacement from the wire, projects it to the reference plane and scales it onto the drift circle defined by the wire.

Definition at line 35 of file CDCRecoHit2D.cc.

{
  // find out if the wire is right or left of the track ( view in flight direction )
  Vector3D trackPosToWire{simHit.getPosWire() - simHit.getPosTrack()};
  CDCRecoHit2D recoHit2D(CDCRLWireHit::fromSimHit(wireHit, simHit),
                         Vector2D(-trackPosToWire.x(), -trackPosToWire.y()));
 
  recoHit2D.snapToDriftCircle();
  return recoHit2D;
}

getAlias()

CDCRecoHit2D getAlias

(

)

const

Getter for the alias version of the reco hit.

Definition at line 105 of file CDCRecoHit2D.cc.

{
  return CDCRecoHit2D(getRLWireHit().getAlias(), -getRecoDisp2D());
}

getAlpha()

double getAlpha ( ) const

inline

Getter for the direction of flight relative to the position.

Definition at line 266 of file CDCRecoHit2D.h.

      {
        return getRecoPos2D().angleWith(getFlightDirection2D());
      }

getFlightDirection2D()

Vector2D getFlightDirection2D ( ) const

inline

Getter for the direction of flight.

Definition at line 259 of file CDCRecoHit2D.h.

      {
        ERotation rotation = static_cast<ERotation>(-getRLInfo());
        return getRecoDisp2D().orthogonal(rotation);
      }

getISuperLayer()

CDC::ISuperLayer getISuperLayer ( ) const

inline

Getter for the superlayer id.

Definition at line 172 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getISuperLayer();
      }

getRecoDisp2D()

const Vector2D & getRecoDisp2D ( ) const

inline

Getter for the displacement from the wire reference position.

Definition at line 253 of file CDCRecoHit2D.h.

      {
        return m_recoDisp2D;
      }

getRecoPos2D()

Vector2D getRecoPos2D ( ) const

inline

Getter for the position in the reference plane.

Definition at line 241 of file CDCRecoHit2D.h.

      {
        return getRecoDisp2D() + getRefPos2D();
      }

getRefDriftLength()

double getRefDriftLength ( ) const

inline

Getter for the drift length at the wire reference position.

Definition at line 220 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getRefDriftLength();
      }

getRefDriftLengthVariance()

double getRefDriftLengthVariance ( ) const

inline

Getter for the uncertainty in the drift length at the wire reference position.

Definition at line 235 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getRefDriftLengthVariance();
      }

getRefPos2D()

const ROOT::Math::XYVector & getRefPos2D ( ) const

inline

Getter for the reference position of the wire.

Definition at line 184 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getRefPos2D();
      }

getRLInfo()

ERightLeft getRLInfo ( ) const

inline

Getter for the right left passage information.

Definition at line 208 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getRLInfo();
      }

getRLWireHit()

const CDCRLWireHit & getRLWireHit ( ) const

inline

Getter for the oriented wire hit associated with the reconstructed hit.

Definition at line 284 of file CDCRecoHit2D.h.

      {
        return m_rlWireHit;
      }

getSignedRefDriftLength()

double getSignedRefDriftLength ( ) const

inline

Getter for the drift length at the wire reference position signed with the right left passage hypotheses.

Definition at line 229 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getSignedRefDriftLength();
      }

getStereoKind()

CDC::EStereoKind getStereoKind ( ) const

inline

Getter for the stereo type of the underlying wire.

Definition at line 160 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getStereoKind();
      }

getWire()

const CDC::CDCWire & getWire ( ) const

inline

Getter for the wire the reconstructed hit associated to.

Definition at line 178 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getWire();
      }

getWireHit()

const CDCWireHit & getWireHit ( ) const

inline

Getter for the wire hit associated with the reconstructed hit.

Definition at line 196 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().getWireHit();
      }

hasWireHit()

bool hasWireHit ( const CDCWireHit & wireHit ) const

inline

Checks if the reconstructed hit is associated with the give wire hit.

Definition at line 202 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().hasWireHit(wireHit);
      }

isAxial()

bool isAxial ( ) const

inline

Indicator if the underlying wire is axial.

Definition at line 166 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().isAxial();
      }

isOnWire()

bool isOnWire ( const CDC::CDCWire & wire ) const

inline

Checks if the reconstructed hit is associated with the give wire.

Definition at line 190 of file CDCRecoHit2D.h.

      {
        return getRLWireHit().isOnWire(wire);
      }

operator const Belle2::CDCHit *()

operator const Belle2::CDCHit * ( ) const

inline

Make the wire hit automatically castable to its underlying cdcHit.

Definition at line 121 of file CDCRecoHit2D.h.

      { return static_cast<const CDCHit*>(getRLWireHit()); }

operator<()

bool operator< ( const CDCRecoHit2D & other ) const

inline

Total ordering relation based on wire hit, left right passage information and displacement in this order of importance.

Definition at line 136 of file CDCRecoHit2D.h.

      {
        return getRLWireHit() <  other.getRLWireHit() or (
                 getRLWireHit() == other.getRLWireHit() and
                 getRecoDisp2D() < other.getRecoDisp2D());
      }

operator==()

bool operator== ( const CDCRecoHit2D & other ) const

inline

Equality comparison based on the oriented wire hit and displacement.

Definition at line 126 of file CDCRecoHit2D.h.

      {
        return getRLWireHit() == other.getRLWireHit() and
               getRecoDisp2D() == other.getRecoDisp2D();
      }

reconstruct3D()

Vector3D reconstruct3D	(	const CDCTrajectory2D &	trajectory2D,
		const double	z = 0 ) const

Reconstruct the three dimensional position (especially of stereo hits) by determining the z coordinate such that the reconstructed position lies on the given two dimensional trajectory as the reference reconstructed position is moved parallel to the stereo wire.

For axial hits the point of closest approach on the trajectory is returned.

Definition at line 129 of file CDCRecoHit2D.cc.

{
  return getRLWireHit().reconstruct3D(trajectory2D, z);
}

reverse()

void reverse

(

)

Turns the orientation in place.

Changes the sign of the right left passage information, since the position remains the same by this reversion.

Definition at line 93 of file CDCRecoHit2D.cc.

{
  m_rlWireHit.reverse();
}

reversed()

CDCRecoHit2D reversed

(

)

const

Returns the recohit with the opposite right left information.

Definition at line 98 of file CDCRecoHit2D.cc.

{
  CDCRecoHit2D reversedRecoHit(*this);
  reversedRecoHit.reverse();
  return reversedRecoHit;
}

setRecoPos2D()

void setRecoPos2D ( const Vector2D & recoPos2D )

inline

Setter for the position in the reference plane.

Definition at line 247 of file CDCRecoHit2D.h.

      {
        m_recoDisp2D = recoPos2D - getRefPos2D();
      }

setRefDriftLength()

void setRefDriftLength	(	double	driftLength,
		bool	snapRecoPos )

Setter for the drift length at the wire reference position.

Definition at line 111 of file CDCRecoHit2D.cc.

{
  double oldDriftLength = m_rlWireHit.getRefDriftLength();
  m_rlWireHit.setRefDriftLength(driftLength);
  if (snapRecoPos) {
    bool switchSide = sign(oldDriftLength) != sign(driftLength);
    snapToDriftCircle(switchSide);
  }
}

setRLInfo()

void setRLInfo ( ERightLeft & rlInfo )

inline

Setter the right left passage information.

Definition at line 214 of file CDCRecoHit2D.h.

      {
        m_rlWireHit.setRLInfo(rlInfo);
      }

setRLWireHit()

void setRLWireHit ( const CDCRLWireHit & rlWireHit )

inline

Setter for the oriented wire hit associated with the reconstructed hit.

Definition at line 290 of file CDCRecoHit2D.h.

      {
        m_rlWireHit = rlWireHit;
      }

snapToDriftCircle()

void snapToDriftCircle

(

bool

switchSide = false

)

Scales the displacement vector in place to lie on the drift circle.

Definition at line 121 of file CDCRecoHit2D.cc.

{
  m_recoDisp2D.normalizeTo(getRLWireHit().getRefDriftLength());
  if (switchSide) {
    m_recoDisp2D = -m_recoDisp2D;
  }
}

Friends And Related Symbol Documentation

operator< [1/4]

bool operator< ( const CDC::CDCWire & wire, const CDCRecoHit2D & recoHit2D )

friend

Defines wires and the two dimensional reconstructed hits as coaligned.

Definition at line 148 of file CDCRecoHit2D.h.

      { return wire < recoHit2D.getRLWireHit(); }

operator< [2/4]

bool operator< ( const CDCRecoHit2D & recoHit2D, const CDC::CDCWire & wire )

friend

Defines wires and the two dimensional reconstructed hits as coaligned.

Definition at line 144 of file CDCRecoHit2D.h.

      { return recoHit2D.getRLWireHit() < wire; }

operator< [3/4]

bool operator< ( const CDCRecoHit2D & recoHit2D, const CDCWireHit & wireHit )

friend

Defines wire hits and the two dimensional reconstructed hits as coaligned.

Definition at line 152 of file CDCRecoHit2D.h.

      { return recoHit2D.getRLWireHit() < wireHit; }

operator< [4/4]

bool operator< ( const CDCWireHit & wireHit, const CDCRecoHit2D & recoHit2D )

friend

Defines wire hits and the two dimensional reconstructed hits as coaligned.

Definition at line 156 of file CDCRecoHit2D.h.

      { return wireHit < recoHit2D.getRLWireHit(); }

Member Data Documentation

m_recoDisp2D

Vector2D m_recoDisp2D

private

Memory for the displacement of the associated wire reference position.

Definition at line 300 of file CDCRecoHit2D.h.

m_rlWireHit

CDCRLWireHit m_rlWireHit

private

Memory for the reference to the associated wire hit.

Definition at line 297 of file CDCRecoHit2D.h.

---

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

• tracking/trackingUtilities/eventdata/hits/include/CDCRecoHit2D.h
• tracking/trackingUtilities/eventdata/hits/src/CDCRecoHit2D.cc