CDCWireHit Class Reference

Class representing a hit wire in the central drift chamber. More...

#include <CDCWireHit.h>

Public Member Functions
	CDCWireHit ()=default
	Default constructor for ROOT compatibility.
	CDCWireHit (const CDCHit *ptrHit, double driftLength, double driftLengthVariance=c_simpleDriftLengthVariance, double chargeDeposit=0, double driftTime=0)
	Constructor associating the CDCHit with estimates of the drift length and charge deposit.
	CDCWireHit (const CDCHit *ptrHit, CDC::TDCCountTranslatorBase *ptrTDCCountTranslator=nullptr, CDC::ADCCountTranslatorBase *ptrADCCountTranslator=nullptr)
	Constructor for augmenting the CDCHit with the geometry information of the CDCWire.
	CDCWireHit (const WireID &wireID, double driftLength, double driftLengthVariance=c_simpleDriftLengthVariance, double chargeDeposit=0)
	Constructor that takes a wire ID and a driftlength at the reference. For testing only!
bool	operator== (const CDCWireHit &rhs) const
	Equality comparison based on the wire and the hit id.
bool	operator< (const CDCWireHit &rhs) const
	Total ordering relation based on the wire and the hit id.
bool	operator< (const CDCHit &hit)
	Defines CDCWireHits and raw CDCHit to be coaligned.
const CDCHit *	getHit () const
	Getter for the CDCHit pointer into the StoreArray.
Index	getStoreIHit () const
	Getter for the index of the hit in the StoreArray holding this hit.
const CDCWire &	getWire () const
	Getter for the CDCWire the hit is located on.
const CDCWire &	attachWire () const
	Reestablishes the pointer of the hit to the wire and returns it Since the DataStore only transport the event data and not "static" geometry information the wire is lost whenever the DataStore is stream across an interprocess boundary or to file.
const WireID &	getWireID () const
	Getter for the WireID of the wire the hit is located on.
EStereoKind	getStereoKind () const
	Getter for the stereo type of the underlying wire.
bool	isAxial () const
	Indicator if the underlying wire is axial.
ISuperLayer	getISuperLayer () const
	Getter for the super layer id.
ILayer	getILayer () const
	Getter for the layer id.
const Vector2D &	getRefPos2D () const
	The two dimensional reference position (z=0) of the underlying wire.
const Vector3D &	getRefPos3D () const
	The three dimensional reference position of the underlying wire.
double	getRefCylindricalR () const
	The distance from the beam line at reference position of the underlying wire.
double	getRefDriftLength () const
	Getter for the drift length at the reference position of the wire.
double	getRefDriftLengthVariance () const
	Getter for the variance of the drift length at the reference position of the wire.
double	getRefChargeDeposit () const
	Getter for the charge due to energy deposit in the drift cell.
bool	isOnWire (const CDCWire &wire) const
	Checks if the wire hit is based on the given wire.
Vector2D	reconstruct2D (const CDCTrajectory2D &trajectory2D) const
	Reconstructs a position of primary ionisation on the drift circle.
Vector3D	reconstruct3D (const CDCTrajectory2D &trajectory2D, ERightLeft rlInfo, double z=0) const
	Attempts to reconstruct a three dimensional position (especially of stereo hits).
Circle2D	conformalTransformed (const Vector2D &relativeTo) const
	Applys the conformal transformation to the drift circle this hit represents.
AutomatonCell &	getAutomatonCell () const
	Mutable getter for the automaton cell.
AutomatonCell *	operator-> () const
	Indirection to the automaton cell for easier access to the flags.
int	getISuperCluster () const
	Getter for the super cluster id.
void	setISuperCluster (int iSuperCluster)
	Setter for the super cluster id.
double	getDriftTime () const
	Return the drift time measured by the CDC for this hit.

Static Public Member Functions
static CDC::TDCCountTranslatorBase &	getTDCCountTranslator ()
	Return an instance of the used TDC count translator.
static CDC::ADCCountTranslatorBase &	getADCCountTranslator ()
	Return an instance of the used ADC count translator.

Static Public Attributes
static constexpr const double	c_simpleDriftLengthVariance = 0.000169
	A default value for the drift length variance if no variance from the drift length translation is available.

Private Attributes
WireID	m_wireID
	Memory for the WireID.
CDCWire const *	m_wire = nullptr
	Memory for the CDCWire pointer - Trailing comment indicates to not stream this member.
AutomatonCell	m_automatonCell {1}
	Memory for the automaton cell.
double	m_refDriftLength = 0
	Memory for the drift length at the wire reference point.
double	m_refDriftLengthVariance = c_simpleDriftLengthVariance
	Memory for the variance of the drift length at the wire reference point.
double	m_refChargeDeposit = 0.0
	Memory for the charge induced by the energy deposit in the drift cell.
int	m_iSuperCluster = -1
	Memory for the super cluster id.
double	m_refDriftTime = 0.0f
	Measured drift time of the CDC hit.
const CDCHit *	m_hit = nullptr
	Memory for the CDCHit pointer.

Friends
bool	operator< (const CDCWireHit &wireHit, const CDCWire &wire)
	Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.
bool	operator< (const CDCWire &wire, const CDCWireHit &wireHit)
	Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.
bool	operator< (const CDCWireHit *wireHit, const CDCWire &wire)
	Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.
bool	operator< (const CDCWire &wire, const CDCWireHit *wireHit)
	Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.
bool	operator< (const CDCWireHit &wireHit, const CDCHit &hit)
	Defines CDCWireHits and raw CDCHit to be coaligned.
bool	operator< (const CDCHit &hit, const CDCWireHit &wireHit)
	Defines wire hits and raw CDCHit to be coaligned.

Detailed Description

Class representing a hit wire in the central drift chamber.

This class combines the measurement information from a CDCHit with the geometry information. It forms the basis of all other higher level tracking objects. It contains an AutomatonCell which defines the flags of usage etc. Additionally it contains references to both the CDCWire instance from the CDCWireTopology and the CDCHit from the StoreArray of the event.

Definition at line 55 of file CDCWireHit.h.

Constructor & Destructor Documentation

CDCWireHit() [1/3]

CDCWireHit	(	const CDCHit *	ptrHit,
		double	driftLength,
		double	driftLengthVariance = c_simpleDriftLengthVariance,
		double	chargeDeposit = 0,
		double	driftTime = 0
	)

Constructor associating the CDCHit with estimates of the drift length and charge deposit.

Also stores the CDCHit necessary for later translation to Genfit.

Parameters

ptrHit	Reference to the CDCHit.
driftLength	Initial estimate of the drift length at the reference position.
driftLengthVariance	Initial estimate of the variance of the dirft length at the reference position.
chargeDeposit	Initial estimate of the deposited charge in the drift cell.
driftTime	Measured drift time

Definition at line 51 of file CDCWireHit.cc.

  : m_wireID(ptrHit->getID())
  , m_wire(CDCWire::getInstance(*ptrHit))
  , m_automatonCell(1)
  , m_refDriftLength(driftLength)
  , m_refDriftLengthVariance(driftLengthVariance)
  , m_refChargeDeposit(chargeDeposit)
  , m_refDriftTime(driftTime)
  , m_hit(ptrHit)
{
}

CDCWireHit() [2/3]

CDCWireHit ( const CDCHit *  ptrHit, CDC::TDCCountTranslatorBase *  ptrTDCCountTranslator = nullptr, CDC::ADCCountTranslatorBase *  ptrADCCountTranslator = nullptr  )

explicit

Constructor for augmenting the CDCHit with the geometry information of the CDCWire.

Binds to the CDCHit and the corresponding wire together and translates the TDC count to a driftlength. Also stores the index of the StoreArray from which the hit has been taken. Necessary for later translation to genfit.

Parameters

ptrHit	Reference to the CDCHit.
ptrTDCCountTranslator	instance of the used TDC count translator (optional)
ptrADCCountTranslator	instance of the used ADC count translator (optional)

Definition at line 67 of file CDCWireHit.cc.

  : m_wireID(ptrHit->getID())
  , m_wire(ptrHit ? CDCWire::getInstance(*ptrHit) : nullptr)
  , m_automatonCell(1)
  , m_hit(ptrHit)
{
  if (not ptrHit) {
    B2ERROR("CDCWireHit constructor invoked with nullptr CDCHit");
    return;
  }
  const CDCHit& hit = *ptrHit;
 
  TDCCountTranslatorBase& tdcCountTranslator =
    ptrTDCCountTranslator ? *ptrTDCCountTranslator : getTDCCountTranslator();
  ADCCountTranslatorBase& adcCountTranslator =
    ptrADCCountTranslator ? *ptrADCCountTranslator : getADCCountTranslator();
 
  float initialTOFEstimate = 0;
 
  float refDriftLengthRight = tdcCountTranslator.getDriftLength(hit.getTDCCount(),
                              getWireID(),
                              initialTOFEstimate,
                              false, // bool leftRight
                              getWire().getRefZ());
 
  float refDriftLengthLeft = tdcCountTranslator.getDriftLength(hit.getTDCCount(),
                             getWireID(),
                             initialTOFEstimate,
                             true, // bool leftRight
                             getWire().getRefZ());
 
  m_refDriftTime = tdcCountTranslator.getDriftTime(hit.getTDCCount(),
                                                   getWireID(),
                                                   initialTOFEstimate,
                                                   getWire().getRefZ(),
                                                   hit.getADCCount());
 
  m_refDriftLength = (refDriftLengthLeft + refDriftLengthRight) / 2.0;
 
  m_refDriftLengthVariance = tdcCountTranslator.getDriftLengthResolution(m_refDriftLength,
                             getWireID(),
                             false, // bool leftRight ?
                             getWire().getRefZ());
 
  m_refChargeDeposit = adcCountTranslator.getCharge(hit.getADCCount(),
                                                    getWireID(),
                                                    false, // bool leftRight
                                                    getWire().getRefZ(),
                                                    0); // theta
}

CDCWireHit() [3/3]

CDCWireHit	(	const WireID &	wireID,
		double	driftLength,
		double	driftLengthVariance = c_simpleDriftLengthVariance,
		double	chargeDeposit = 0
	)

Constructor that takes a wire ID and a driftlength at the reference. For testing only!

Definition at line 120 of file CDCWireHit.cc.

  : m_wireID(wireID)
  , m_wire(CDCWire::getInstance(wireID))
  , m_automatonCell(1)
  , m_refDriftLength(driftLength)
  , m_refDriftLengthVariance(driftLengthVariance)
  , m_refChargeDeposit(chargeDeposit)
  , m_hit(nullptr)
{
}

Member Function Documentation

attachWire()

const CDCWire & attachWire

(

)

const

Reestablishes the pointer of the hit to the wire and returns it Since the DataStore only transport the event data and not "static" geometry information the wire is lost whenever the DataStore is stream across an interprocess boundary or to file.

In this case this method can be called to lookup the wire again.

Definition at line 159 of file CDCWireHit.cc.

{
  m_wire = CDCWire::getInstance(m_wireID);
  assert(m_wire);
  return *m_wire;
}

conformalTransformed()

Circle2D conformalTransformed

(

const Vector2D &

relativeTo

)

const

Applys the conformal transformation to the drift circle this hit represents.

Although not advisable to use we provide an interface to obtain the inversion at the unit circle as a transformation to the so called conformal space. We provide the self-inverse for of the transformation

• 
• 
• 

Definition at line 200 of file CDCWireHit.cc.

{
  Circle2D driftCircle(getRefPos2D() - relativeTo, getRefDriftLength());
  driftCircle.conformalTransform();
  return driftCircle;
}

getADCCountTranslator()

ADCCountTranslatorBase & getADCCountTranslator ( )

static

Return an instance of the used ADC count translator.

Definition at line 45 of file CDCWireHit.cc.

{
  static CDC::LinearGlobalADCCountTranslator s_adcCountTranslator;
  return s_adcCountTranslator;
}

getAutomatonCell()

AutomatonCell & getAutomatonCell ( ) const

inline

Mutable getter for the automaton cell.

Definition at line 286 of file CDCWireHit.h.

      {
        return m_automatonCell;
      }

getDriftTime()

double getDriftTime ( ) const

inline

Return the drift time measured by the CDC for this hit.

Definition at line 310 of file CDCWireHit.h.

      {
        return m_refDriftTime;
      }

getHit()

const CDCHit * getHit ( ) const

inline

Getter for the CDCHit pointer into the StoreArray.

Definition at line 159 of file CDCWireHit.h.

      {
        return m_hit;
      }

getILayer()

ILayer getILayer ( ) const

inline

Getter for the layer id.

Definition at line 209 of file CDCWireHit.h.

      {
        return getWireID().getILayer();
      }

getISuperCluster()

int getISuperCluster ( ) const

inline

Getter for the super cluster id.

Definition at line 298 of file CDCWireHit.h.

      {
        return m_iSuperCluster;
      }

getISuperLayer()

ISuperLayer getISuperLayer ( ) const

inline

Getter for the super layer id.

Definition at line 203 of file CDCWireHit.h.

      {
        return getWireID().getISuperLayer();
      }

getRefChargeDeposit()

double getRefChargeDeposit ( ) const

inline

Getter for the charge due to energy deposit in the drift cell.

Definition at line 236 of file CDCWireHit.h.

      {
        return m_refChargeDeposit;
      }

getRefCylindricalR()

double getRefCylindricalR

(

)

const

The distance from the beam line at reference position of the underlying wire.

Definition at line 222 of file CDCWireHit.cc.

{
  return getWire().getRefCylindricalR();
}

getRefDriftLength()

double getRefDriftLength ( ) const

inline

Getter for the drift length at the reference position of the wire.

Definition at line 224 of file CDCWireHit.h.

      {
        return m_refDriftLength;
      }

getRefDriftLengthVariance()

double getRefDriftLengthVariance ( ) const

inline

Getter for the variance of the drift length at the reference position of the wire.

Definition at line 230 of file CDCWireHit.h.

      {
        return m_refDriftLengthVariance;
      }

getRefPos2D()

const Vector2D & getRefPos2D

(

)

const

The two dimensional reference position (z=0) of the underlying wire.

Definition at line 212 of file CDCWireHit.cc.

{
  return getWire().getRefPos2D();
}

getRefPos3D()

const Vector3D & getRefPos3D

(

)

const

The three dimensional reference position of the underlying wire.

Definition at line 217 of file CDCWireHit.cc.

{
  return getWire().getRefPos3D();
}

getStereoKind()

EStereoKind getStereoKind ( ) const

inline

Getter for the stereo type of the underlying wire.

Definition at line 191 of file CDCWireHit.h.

      {
        return ISuperLayerUtil::getStereoKind(getISuperLayer());
      }

getStoreIHit()

Index getStoreIHit

(

)

const

Getter for the index of the hit in the StoreArray holding this hit.

Definition at line 207 of file CDCWireHit.cc.

{
  return getHit() ? getHit()->getArrayIndex() : c_InvalidIndex;
}

getTDCCountTranslator()

TDCCountTranslatorBase & getTDCCountTranslator ( )

static

Return an instance of the used TDC count translator.

Definition at line 39 of file CDCWireHit.cc.

{
  static CDC::RealisticTDCCountTranslator s_tdcCountTranslator;
  return s_tdcCountTranslator;
}

getWire()

const CDCWire & getWire ( ) const

inline

Getter for the CDCWire the hit is located on.

Definition at line 168 of file CDCWireHit.h.

      {
        // if (not m_wire) return attachWire();
        if (not m_wire) return attachWire();
        return *m_wire;
      }

getWireID()

const WireID & getWireID ( ) const

inline

Getter for the WireID of the wire the hit is located on.

Definition at line 185 of file CDCWireHit.h.

      {
        return m_wireID;
      }

isAxial()

bool isAxial ( ) const

inline

Indicator if the underlying wire is axial.

Definition at line 197 of file CDCWireHit.h.

      {
        return ISuperLayerUtil::isAxial(getISuperLayer());
      }

isOnWire()

bool isOnWire ( const CDCWire &  wire ) const

inline

Checks if the wire hit is based on the given wire.

Definition at line 242 of file CDCWireHit.h.

      {
        return &getWire() == &wire;
      }

operator->()

AutomatonCell * operator-> ( ) const

inline

Indirection to the automaton cell for easier access to the flags.

Definition at line 292 of file CDCWireHit.h.

      {
        return &m_automatonCell;
      }

operator<() [1/2]

bool operator<

(

const CDCHit &

hit

)

Defines CDCWireHits and raw CDCHit to be coaligned.

Definition at line 134 of file CDCWireHit.cc.

{
  return this->getWireID().getEWire() < hit.getID();
}

operator<() [2/2]

bool operator< ( const CDCWireHit &  rhs ) const

inline

Total ordering relation based on the wire and the hit id.

Definition at line 113 of file CDCWireHit.h.

      {
        return
          std::make_pair(getWireID().getEWire(), getRefDriftLength()) <
          std::make_pair(rhs.getWireID().getEWire(), rhs.getRefDriftLength());
      }

operator==()

bool operator== ( const CDCWireHit &  rhs ) const

inline

Equality comparison based on the wire and the hit id.

Definition at line 107 of file CDCWireHit.h.

      {
        return getWireID() == rhs.getWireID() and getRefDriftLength() == rhs.getRefDriftLength();
      }

reconstruct2D()

Vector2D reconstruct2D

(

const CDCTrajectory2D &

trajectory2D

)

const

Reconstructs a position of primary ionisation on the drift circle.

The result is the position of closest approach on the drift circle to the trajectory.

All positions and the trajectory are interpreted to lie at z=0. Also the right left passage hypotheses does not play a role in the reconstruction in any way.

Definition at line 166 of file CDCWireHit.cc.

{
  const Vector2D& refPos2D = getRefPos2D();
  Vector2D recoPos2D = trajectory2D.getClosest(refPos2D);
 
  const Vector2D& wirePos2D = getWire().getRefPos2D();
  const double driftLength = getRefDriftLength();
 
  Vector2D disp2D = recoPos2D - wirePos2D;
 
  // Fix the displacement to lie on the drift circle.
  disp2D.normalizeTo(driftLength);
  return wirePos2D + disp2D;
}

reconstruct3D()

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

Attempts to reconstruct a three dimensional position (especially of stereo hits).

This method makes a distinct difference between axial and stereo hits:

• Stereo hits are moved out of the reference plane such that the oriented drift circle meets the trajectory in one point. Therefore the left right passage hypothesis has to be taken into account
• For axial hits the reconstructed position is undefined in the z coordinate. Also the drift circle cannot be moved such that it would meet the trajectory. Hence we default to the result of reconstruct2D, which yield the closest approach of the drift circle to the trajectory in the reference plane.

Definition at line 181 of file CDCWireHit.cc.

{
  const EStereoKind stereoType = getStereoKind();
 
  if (stereoType == EStereoKind::c_StereoV or stereoType == EStereoKind::c_StereoU) {
    const WireLine& wireLine = getWire().getWireLine();
    const double signedDriftLength = isValid(rlInfo) ? static_cast<double>(rlInfo) * getRefDriftLength() : 0.0;
    return trajectory2D.reconstruct3D(wireLine, signedDriftLength, z);
 
  } else { /*if (stereoType == EStereoKind::c_Axial)*/
    const Vector2D recoPos2D = reconstruct2D(trajectory2D);
    // for axial wire we can not determine the z coordinate by looking at the xy projection only
    // we set it the basic assumption.
    return Vector3D(recoPos2D, z);
  }
}

setISuperCluster()

void setISuperCluster ( int  iSuperCluster )

inline

Setter for the super cluster id.

Definition at line 304 of file CDCWireHit.h.

      {
        m_iSuperCluster = iSuperCluster;
      }

Friends And Related Function Documentation

operator< [1/4]

bool operator< ( const CDCWire &  wire, const CDCWireHit &  wireHit  )

friend

Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.

Definition at line 128 of file CDCWireHit.h.

      {
        return &wire < &wireHit.getWire();
      }

operator< [2/4]

bool operator< ( const CDCWire &  wire, const CDCWireHit *  wireHit  )

friend

Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.

Definition at line 143 of file CDCWireHit.h.

      {
        assert(wireHit);
        return wire < *wireHit;
      }

operator< [3/4]

bool operator< ( const CDCWireHit &  wireHit, const CDCWire &  wire  )

friend

Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.

Definition at line 121 of file CDCWireHit.h.

      {
        return &wireHit.getWire() < &wire;
      }

operator< [4/4]

bool operator< ( const CDCWireHit *  wireHit, const CDCWire &  wire  )

friend

Defines CDCWires and CDCWireHits to be coaligned on the wire on which they are based.

Definition at line 135 of file CDCWireHit.h.

      {
        assert(wireHit);
        return *wireHit < wire;
      }

Member Data Documentation

c_simpleDriftLengthVariance

constexpr const double c_simpleDriftLengthVariance = 0.000169

staticconstexpr

A default value for the drift length variance if no variance from the drift length translation is available.

Definition at line 64 of file CDCWireHit.h.

m_automatonCell

AutomatonCell m_automatonCell {1}

mutableprivate

Memory for the automaton cell.

Definition at line 323 of file CDCWireHit.h.

m_hit

const CDCHit* m_hit = nullptr

private

Memory for the CDCHit pointer.

Definition at line 341 of file CDCWireHit.h.

m_iSuperCluster

int m_iSuperCluster = -1

private

Memory for the super cluster id.

Definition at line 335 of file CDCWireHit.h.

m_refChargeDeposit

double m_refChargeDeposit = 0.0

private

Memory for the charge induced by the energy deposit in the drift cell.

Definition at line 332 of file CDCWireHit.h.

m_refDriftLength

double m_refDriftLength = 0

private

Memory for the drift length at the wire reference point.

Definition at line 326 of file CDCWireHit.h.

m_refDriftLengthVariance

double m_refDriftLengthVariance = c_simpleDriftLengthVariance

private

Memory for the variance of the drift length at the wire reference point.

Definition at line 329 of file CDCWireHit.h.

m_refDriftTime

double m_refDriftTime = 0.0f

private

Measured drift time of the CDC hit.

Definition at line 338 of file CDCWireHit.h.

m_wire

CDCWire const* m_wire = nullptr

mutableprivate

Memory for the CDCWire pointer - Trailing comment indicates to not stream this member.

Definition at line 320 of file CDCWireHit.h.

m_wireID

WireID m_wireID

private

Memory for the WireID.

Definition at line 317 of file CDCWireHit.h.

---

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

• tracking/trackFindingCDC/eventdata/hits/include/CDCWireHit.h
• tracking/trackFindingCDC/eventdata/hits/src/CDCWireHit.cc