CDCTrajectory2D Class Reference

Particle trajectory as it is seen in xy projection represented as a circle. More...

#include <CDCTrajectory2D.h>

Public Member Functions
	CDCTrajectory2D ()
	Default constructor for ROOT compatibility.
	CDCTrajectory2D (const UncertainPerigeeCircle &perigeeCircle)
	Constructs a trajectory from a generalized circle.
	CDCTrajectory2D (const ROOT::Math::XYVector &localOrigin, const UncertainPerigeeCircle &localPerigeeCircle, double flightTime=NAN)
	Constructs a trajectory from a generalized circle and a start point.
	CDCTrajectory2D (const ROOT::Math::XYVector &pos2D, double time, const ROOT::Math::XYVector &mom2D, double charge, double bZ)
	Construct a trajectory with given start point, transverse momentum at the start point, the given charge and the magnetic field value in z direction.
	CDCTrajectory2D (const ROOT::Math::XYVector &pos2D, double time, const ROOT::Math::XYVector &mom2D, double charge)
	Construct a trajectory with given start point, transverse momentum at the start point and given charge.
bool	isFitted () const
	Checks if the circle is already set to a valid value.
void	clear ()
	Clears all information from this trajectory.
void	reverse ()
	Reverses the trajectory in place.
CDCTrajectory2D	reversed () const
	Returns the reverse trajectory as a copy.
std::array< double, 2 >	reconstructBothZ (const CDC::WireLine &wireLine, double distance=0.0, double z=0) const
	Gives the two z positions where the given drift circle on the wire line touches the trajectory.
double	reconstructZ (const CDC::WireLine &wireLine, double distance=0.0, double z=0) const
	Gives the one z positions within the CDC closest to the given z where the given drift circle on the wire line touches the trajectory.
std::array< ROOT::Math::XYZVector, 2 >	reconstructBoth3D (const CDC::WireLine &wireLine, double distance=0.0, double z=0) const
	Gives the two three dimensional points where the drift circle touches the wire line.
ROOT::Math::XYZVector	reconstruct3D (const CDC::WireLine &wireLine, double distance=0.0, double z=0) const
	Gives the one three dimensional positions within the CDC closest to the given z where the given drift circle on the wire line touches the trajectory.
ROOT::Math::XYVector	getClosest (const ROOT::Math::XYVector &point) const
	Calculates the closest approach on the trajectory to the given point.
CDC::ISuperLayer	getNextISuperLayer () const
	Indicates which superlayer the trajectory traverses after the one, where the start point of the trajectory is located.
CDC::ISuperLayer	getPreviousISuperLayer () const
	Indicates which superlayer the trajectory traverses before the one, where the start point of the trajectory is located.
CDC::ISuperLayer	getNextAxialISuperLayer () const
	Indicates which axial superlayer the trajectory traverses after the one, where the start point of the trajectory is located.
CDC::ISuperLayer	getPreviousAxialISuperLayer () const
	Indicates which axial superlayer the trajectory traverses before the one, where the start point of the trajectory is located.
CDC::ISuperLayer	getMaximalISuperLayer () const
	Indicates the maximal superlayer the trajectory traverses.
CDC::ISuperLayer	getStartISuperLayer () const
	Indicates the superlayer the trajectory starts in.
CDC::ISuperLayer	getMinimalISuperLayer () const
	Indicates the minimal superlayer the trajectory traverses.
template<class AHits>
EForwardBackward	isForwardOrBackwardTo (const AHits &hits) const
	Calculates if this trajectory and the hits are coaligned Returns:
template<class AFromHits, class AToHits>
double	getArcLength2DGap (const AFromHits &fromHits, const AToHits &toHits) const
	Calculates the perpendicular travel distance from the last position of the fromHits to the first position of the toHits.
template<class AFromHits, class AToHits>
double	getArcLength2DFrontOffset (const AFromHits &fromHits, const AToHits &toHits) const
	Calculates the perpendicular travel distance from the first position of the fromHits to the first position of the toHits.
template<class AFromHits, class AToHits>
double	getArcLength2DBackOffset (const AFromHits &fromHits, const AToHits &toHits) const
	Calculates the perpendicular travel distance from the last position of the fromHits to the last position of the toHits.
template<class AHits>
double	getTotalArcLength2D (const AHits &hits) const
	Calculates the perpendicular travel distance from the first position of the hits to the last position of the hits.
double	calcArcLength2D (const ROOT::Math::XYVector &point) const
	Calculate the travel distance from the start position of the trajectory.
double	calcArcLength2DBetween (const ROOT::Math::XYVector &fromPoint, const ROOT::Math::XYVector &toPoint) const
	Calculate the travel distance between the two given positions Returns the travel distance on the trajectory from the first given point to the second given point.
double	getArcLength2DPeriod () const
	Getter for the arc length for one round trip around the trajectory.
void	setPosMom2D (const ROOT::Math::XYVector &pos2D, const ROOT::Math::XYVector &mom2D, double charge)
	Setter for start point and momentum at the start point subjected to the charge sign.
ESign	getChargeSign () const
	Gets the charge sign of the trajectory.
double	getAbsMom2D (double bZ) const
	Get the estimation for the absolute value of the transvers momentum.
double	getAbsMom2D () const
	Get the estimation for the absolute value of the transvers momentum.
ROOT::Math::XYVector	getMom2DAtSupport (const double bZ) const
	Get the momentum at the support point of the trajectory.
ROOT::Math::XYVector	getMom2DAtSupport () const
	Get the momentum at the support point of the trajectory.
ROOT::Math::XYVector	getFlightDirection2D (const ROOT::Math::XYVector &point) const
	Get the unit direction of flight at the given point, where arcLength2D = 0.
ROOT::Math::XYVector	getFlightDirection2DAtSupport () const
	Get the unit direction of flight at the support point, where arcLength2D = 0.
bool	isMovingOutward () const
	Indicates if the trajectory is moving outwards or inwards (to or away from the origin) from the start point on.
ROOT::Math::XYVector	getPos2DAtArcLength2D (double arcLength2D)
	Getter for the position at a given two dimensional arc length.
ROOT::Math::XYVector	getSupport () const
	Get the support point of the trajectory in global coordinates.
ROOT::Math::XYVector	getGlobalPerigee () const
	Getter for the closest approach on the trajectory to the global origin.
ROOT::Math::XYVector	getGlobalCenter () const
	Getter for the center of the trajectory in global coordinates.
ROOT::Math::XYVector	getOuterExit (double factor=1) const
	Calculates the point where the trajectory meets the outer wall of the CDC.
ROOT::Math::XYVector	getInnerExit () const
	Calculates the point where the trajectory meets the inner wall of the CDC.
ROOT::Math::XYVector	getExit () const
	Calculates the point where the trajectory leaves the CDC.
bool	isCurler (double factor=1) const
	Checks if the trajectory leaves the outer radius of the CDC times the given tolerance factor.
bool	isOriginer (double factor=1) const
	Checks if the trajectory intersects with the inner radius of the CDC time the given tolerance factor.
double	getMaximalCylindricalR () const
	Getter for the maximal distance from the origin.
double	getMinimalCylindricalR () const
	Getter for the minimal distance from the origin - same as absolute value of the impact parameter.
double	getGlobalImpact () const
	Getter for the signed impact parameter of the trajectory.
double	getDist2D (const ROOT::Math::XYVector &point) const
	Calculates the distance from the point to the trajectory as seen from the xy projection.
ERightLeft	isRightOrLeft (const ROOT::Math::XYVector &point) const
	Checks if the given point is to the right or to the left of the trajectory.
double	getCurvature () const
	Getter for the curvature as seen from the xy projection.
double	getLocalCovariance (EPerigeeParameter iRow, EPerigeeParameter iCol) const
	Getter for an individual element of the covariance matrix of the local helix parameters.
double	getLocalVariance (EPerigeeParameter i) const
	Getter for an individual diagonal element of the covariance matrix of the local helix parameters.
PerigeeCircle	getGlobalCircle () const
	Getter for the circle in global coordinates.
void	setGlobalCircle (const UncertainPerigeeCircle &perigeeCircle)
	Setter for the generalized circle that describes the trajectory.
const UncertainPerigeeCircle &	getLocalCircle () const
	Getter for the circle in local coordinates.
double	getPValue () const
	Getter for p-value.
double	getChi2 () const
	Getter for the chi2 value of the circle fit.
void	setChi2 (const double chi2)
	Setter for the chi square value of the circle fit.
size_t	getNDF () const
	Getter for the number of degrees of freedom of the circle fit.
void	setNDF (std::size_t ndf)
	Setter for the number of degrees of freedom of the circle fit.
void	setLocalCircle (const UncertainPerigeeCircle &localPerigeeCircle)
	Setter for the generalized circle that describes the trajectory.
const ROOT::Math::XYVector &	getLocalOrigin () const
	Getter for the origin of the local coordinate system.
double	setLocalOrigin (const ROOT::Math::XYVector &localOrigin)
	Setter for the origin of the local coordinate system.
double	getFlightTime () const
	Getter for the time when the particle reached the support point position.
void	setFlightTime (double flightTime)
	Setter for the time when the particle reached the support point position.

Private Member Functions
CDC::ISuperLayer	getISuperLayerAfter (CDC::ISuperLayer iSuperLayer, bool movingOutward) const
	Returns which superlayer is traversed after the current one following the trajectory outward or inward as indicated by the boolean input.
CDC::ISuperLayer	getISuperLayerAfterStart (bool movingOutward) const
	Returns which superlayer is traversed after the current one following the trajectory outward or inward as indicated by the boolean input.
CDC::ISuperLayer	getISuperLayerAfterStart (EForwardBackward forwardBackwardInfo) const
	Indicates which superlayer is traversed after the current one following the trajectory forward or backward as indicated by the input.
CDC::ISuperLayer	getAxialISuperLayerAfterStart (EForwardBackward forwardBackwardInfo) const
	Indicates which axial superlayer is traversed after the one, where the start point of the trajectory is located considering if you want to follow the trajectory in the forward or backward direction.

Private Attributes
ROOT::Math::XYVector	m_localOrigin
	Memory for local coordinate origin of the circle representing the trajectory in global coordinates.
UncertainPerigeeCircle	m_localPerigeeCircle
	Memory for the generalized circle describing the trajectory in coordinates from the local origin.
double	m_flightTime = NAN
	Memory for the estimation of the time at which the particle arrived at the support point.

Detailed Description

Particle trajectory as it is seen in xy projection represented as a circle.

Definition at line 39 of file CDCTrajectory2D.h.

Constructor & Destructor Documentation

CDCTrajectory2D() [1/5]

CDCTrajectory2D

(

)

Default constructor for ROOT compatibility.

Definition at line 37 of file CDCTrajectory2D.cc.

  : m_localOrigin()
  , m_localPerigeeCircle()
{
}

CDCTrajectory2D() [2/5]

CDCTrajectory2D ( const UncertainPerigeeCircle & perigeeCircle )

explicit

Constructs a trajectory from a generalized circle.

Constructs a trajectory which is described by the given line or circle. The start point is set to the closest approach to the origin.

Definition at line 43 of file CDCTrajectory2D.cc.

  : m_localOrigin(0.0, 0.0)
  , m_localPerigeeCircle(perigeeCircle)
{
}

CDCTrajectory2D() [3/5]

CDCTrajectory2D	(	const ROOT::Math::XYVector &	localOrigin,
		const UncertainPerigeeCircle &	localPerigeeCircle,
		double	flightTime = NAN )

Constructs a trajectory from a generalized circle and a start point.

Constructs a trajectory which is described by the given line or circle and starts in the given point. The point is taken to be the closest approach to the circle.

Definition at line 49 of file CDCTrajectory2D.cc.

  : m_localOrigin(localOrigin)
  , m_localPerigeeCircle(localPerigeeCircle)
  , m_flightTime(flightTime)
{
}

CDCTrajectory2D() [4/5]

CDCTrajectory2D	(	const ROOT::Math::XYVector &	pos2D,
		double	time,
		const ROOT::Math::XYVector &	mom2D,
		double	charge,
		double	bZ )

Construct a trajectory with given start point, transverse momentum at the start point, the given charge and the magnetic field value in z direction.

Definition at line 58 of file CDCTrajectory2D.cc.

  : m_localOrigin(pos2D)
  , m_localPerigeeCircle(CDCBFieldUtil::absMom2DToCurvature(mom2D.R(), charge, bZ),
                         VectorUtil::unit(mom2D),
                         0.0)
  , m_flightTime(time)
{
}

CDCTrajectory2D() [5/5]

CDCTrajectory2D	(	const ROOT::Math::XYVector &	pos2D,
		double	time,
		const ROOT::Math::XYVector &	mom2D,
		double	charge )

Construct a trajectory with given start point, transverse momentum at the start point and given charge.

Definition at line 71 of file CDCTrajectory2D.cc.

  : m_localOrigin(pos2D)
  , m_localPerigeeCircle(CDCBFieldUtil::absMom2DToCurvature(mom2D.R(), charge, pos2D),
                         VectorUtil::unit(mom2D),
                         0.0)
  , m_flightTime(time)
{
}

Member Function Documentation

calcArcLength2D()

double calcArcLength2D ( const ROOT::Math::XYVector & point ) const

inline

Calculate the travel distance from the start position of the trajectory.

Returns the travel distance on the trajectory from the start point to
the given point. This is subjected to a discontinuity at the far point
of the circle. Hence the value return is in the range from -pi*radius to pi*radius
If you have a heavily curling track you have care about the feasibility of this
calculation.

Definition at line 263 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->arcLengthBetween(ROOT::Math::XYVector(0.0, 0.0), point - getLocalOrigin());
      }

calcArcLength2DBetween()

double calcArcLength2DBetween ( const ROOT::Math::XYVector & fromPoint, const ROOT::Math::XYVector & toPoint ) const

inline

Calculate the travel distance between the two given positions Returns the travel distance on the trajectory from the first given point to
the second given point.

This is subjected to a discontinuity at the far point
of the circle. Hence the value return is in the range from -pi*radius to pi*radius
If you have a heavily curling track you have care about the feasibility of this
calculation.

Definition at line 276 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->arcLengthBetween(fromPoint - getLocalOrigin(),
                                                  toPoint - getLocalOrigin());
      }

clear()

void clear

(

)

Clears all information from this trajectory.

Definition at line 88 of file CDCTrajectory2D.cc.

{
  m_localOrigin.SetXY(0.0, 0.0);
  m_localPerigeeCircle.invalidate();
  m_flightTime = NAN;
}

getAbsMom2D() [1/2]

double getAbsMom2D

(

)

const

Get the estimation for the absolute value of the transvers momentum.

Definition at line 291 of file CDCTrajectory2D.cc.

{
  ROOT::Math::XYVector position = getSupport();
  return CDCBFieldUtil::curvatureToAbsMom2D(getLocalCircle()->curvature(), position);
}

getAbsMom2D() [2/2]

double getAbsMom2D

(

double

bZ

)

const

Get the estimation for the absolute value of the transvers momentum.

Definition at line 286 of file CDCTrajectory2D.cc.

{
  return CDCBFieldUtil::curvatureToAbsMom2D(getLocalCircle()->curvature(), bZ);
}

getArcLength2DBackOffset()

template<class AFromHits, class AToHits>

double getArcLength2DBackOffset ( const AFromHits & fromHits, const AToHits & toHits ) const

inline

Calculates the perpendicular travel distance from the last position of the fromHits to the last position of the toHits.

Definition at line 237 of file CDCTrajectory2D.h.

      {
        const ROOT::Math::XYVector& fromRecoPos2D = fromHits.back().getRecoPos2D();
        const ROOT::Math::XYVector& toRecoPos2D = toHits.back().getRecoPos2D();
        return calcArcLength2DBetween(fromRecoPos2D, toRecoPos2D);
      }

getArcLength2DFrontOffset()

template<class AFromHits, class AToHits>

double getArcLength2DFrontOffset ( const AFromHits & fromHits, const AToHits & toHits ) const

inline

Calculates the perpendicular travel distance from the first position of the fromHits to the first position of the toHits.

Definition at line 225 of file CDCTrajectory2D.h.

      {
        const ROOT::Math::XYVector& fromRecoPos2D = fromHits.front().getRecoPos2D();
        const ROOT::Math::XYVector& toRecoPos2D = toHits.front().getRecoPos2D();
        return calcArcLength2DBetween(fromRecoPos2D, toRecoPos2D);
      }

getArcLength2DGap()

template<class AFromHits, class AToHits>

double getArcLength2DGap ( const AFromHits & fromHits, const AToHits & toHits ) const

inline

Calculates the perpendicular travel distance from the last position of the fromHits to the first position of the toHits.

Definition at line 213 of file CDCTrajectory2D.h.

      {
        const ROOT::Math::XYVector& fromRecoPos2D = fromHits.back().getRecoPos2D();
        const ROOT::Math::XYVector& toRecoPos2D = toHits.front().getRecoPos2D();
        return calcArcLength2DBetween(fromRecoPos2D, toRecoPos2D);
      }

getArcLength2DPeriod()

double getArcLength2DPeriod ( ) const

inline

Getter for the arc length for one round trip around the trajectory.

Definition at line 282 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->arcLengthPeriod();
      }

getAxialISuperLayerAfterStart()

ISuperLayer getAxialISuperLayerAfterStart ( EForwardBackward forwardBackwardInfo ) const

private

Indicates which axial superlayer is traversed after the one, where the start point of the trajectory is located considering if you want to follow the trajectory in the forward or backward direction.

Definition at line 221 of file CDCTrajectory2D.cc.

{
  bool movingOutward = isMovingOutward();
  if (forwardBackwardInfo == EForwardBackward::c_Backward) {
    movingOutward = not movingOutward;
  }
  ISuperLayer startISuperLayer = getStartISuperLayer();
  if (ISuperLayerUtil::isInvalid(startISuperLayer)) return ISuperLayerUtil::c_Invalid;
 
  ISuperLayer nextISuperLayer = getISuperLayerAfter(startISuperLayer, movingOutward);
  if (ISuperLayerUtil::isInvalid(nextISuperLayer)) return ISuperLayerUtil::c_Invalid;
  if (ISuperLayerUtil::isAxial(nextISuperLayer)) return nextISuperLayer;
 
  ISuperLayer iSuperLayerStep = nextISuperLayer - startISuperLayer;
  assert(std::abs(iSuperLayerStep) == 1);
  bool nextMovingOutward = iSuperLayerStep > 0;
  return getISuperLayerAfter(nextISuperLayer, nextMovingOutward);
}

getChargeSign()

ESign getChargeSign

(

)

const

Gets the charge sign of the trajectory.

Definition at line 281 of file CDCTrajectory2D.cc.

{
  return CDCBFieldUtil::ccwInfoToChargeSign(getLocalCircle()->orientation());
}

getChi2()

double getChi2 ( ) const

inline

Getter for the chi2 value of the circle fit.

Definition at line 471 of file CDCTrajectory2D.h.

      {
        return getLocalCircle().chi2();
      }

getClosest()

ROOT::Math::XYVector getClosest

(

const ROOT::Math::XYVector &

point

)

const

Calculates the closest approach on the trajectory to the given point.

Definition at line 174 of file CDCTrajectory2D.cc.

{
  return getLocalCircle()->closest(point - getLocalOrigin()) + getLocalOrigin();
}

getCurvature()

double getCurvature ( ) const

inline

Getter for the curvature as seen from the xy projection.

Definition at line 425 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->curvature();
      }

getDist2D()

double getDist2D ( const ROOT::Math::XYVector & point ) const

inline

Calculates the distance from the point to the trajectory as seen from the xy projection.

Definition at line 412 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->distance(point - getLocalOrigin());
      }

getExit()

ROOT::Math::XYVector getExit

(

)

const

Calculates the point where the trajectory leaves the CDC.

This method returns the first point in forward flight direction from the start point of the trajectory where it meets either the radius of the inner most layer or the outer radius of the outer most wall. If the trajectory does not leave the CDC by the inner or outer wall this will return ROOT::Math::XYVector(nan,nan).

Definition at line 337 of file CDCTrajectory2D.cc.

{
  const ROOT::Math::XYVector outerExit = getOuterExit();
  const ROOT::Math::XYVector innerExit = getInnerExit();
  const ROOT::Math::XYVector localExit =  getLocalCircle()->chooseNextForwardOf(ROOT::Math::XYVector(0, 0),
                                          outerExit - getLocalOrigin(),
                                          innerExit - getLocalOrigin());
  return localExit + getLocalOrigin();
}

getFlightDirection2D()

ROOT::Math::XYVector getFlightDirection2D ( const ROOT::Math::XYVector & point ) const

inline

Get the unit direction of flight at the given point, where arcLength2D = 0.

Definition at line 313 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->tangential(point - getLocalOrigin());
      }

getFlightDirection2DAtSupport()

ROOT::Math::XYVector getFlightDirection2DAtSupport ( ) const

inline

Get the unit direction of flight at the support point, where arcLength2D = 0.

Definition at line 319 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->tangential();
      }

getFlightTime()

double getFlightTime ( ) const

inline

Getter for the time when the particle reached the support point position.

Definition at line 525 of file CDCTrajectory2D.h.

      {
        return m_flightTime;
      }

getGlobalCenter()

ROOT::Math::XYVector getGlobalCenter ( ) const

inline

Getter for the center of the trajectory in global coordinates.

Definition at line 350 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->center() + m_localOrigin;
      }

getGlobalCircle()

PerigeeCircle getGlobalCircle ( ) const

inline

Getter for the circle in global coordinates.

Definition at line 444 of file CDCTrajectory2D.h.

      {
        PerigeeCircle result = getLocalCircle();
        result.passiveMoveBy(-getLocalOrigin());
        return result;
      }

getGlobalImpact()

double getGlobalImpact ( ) const

inline

Getter for the signed impact parameter of the trajectory.

Definition at line 406 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->distance(-m_localOrigin);
      }

getGlobalPerigee()

ROOT::Math::XYVector getGlobalPerigee ( ) const

inline

Getter for the closest approach on the trajectory to the global origin.

Definition at line 344 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->closest(-m_localOrigin) + m_localOrigin;
      }

getInnerExit()

ROOT::Math::XYVector getInnerExit

(

)

const

Calculates the point where the trajectory meets the inner wall of the CDC.

This method returns the first point in forward flight direction from the start point of the trajectory where it meets the inner radius of the inner most layer. If the trajectory does not meet the CDC by the inner wall this will return ROOT::Math::XYVector(nan,nan)

Definition at line 297 of file CDCTrajectory2D.cc.

{
  const CDCWireTopology& topology = CDCWireTopology::getInstance();
  const CDCWireLayer& innerMostLayer = topology.getWireLayers().front();
  double innerCylindricalR = innerMostLayer.getInnerCylindricalR();
 
  const ROOT::Math::XYVector support = getSupport();
  const PerigeeCircle globalCircle = getGlobalCircle();
  if (support.Mag2() < innerCylindricalR * innerCylindricalR) {
    // If we start within the inner volume of the CDC we want the trajectory to enter the CDC
    // and not stop at first intersection with the inner wall.
    // Therefore we take the inner exit that comes after the apogee (far point of the circle).
    const ROOT::Math::XYVector apogee = globalCircle.apogee();
    return globalCircle.atCylindricalRForwardOf(apogee, innerCylindricalR);
 
  } else {
    return globalCircle.atCylindricalRForwardOf(support, innerCylindricalR);
  }
}

getISuperLayerAfter()

ISuperLayer getISuperLayerAfter ( CDC::ISuperLayer iSuperLayer, bool movingOutward ) const

private

Returns which superlayer is traversed after the current one following the trajectory outward or inward as indicated by the boolean input.

Definition at line 179 of file CDCTrajectory2D.cc.

{
  if (ISuperLayerUtil::isInvalid(iSuperLayer)) return ISuperLayerUtil::c_Invalid;
 
  ISuperLayer minimalISuperLayer = getMinimalISuperLayer();
  ISuperLayer maximalISuperLayer = getMaximalISuperLayer();
  if (minimalISuperLayer == maximalISuperLayer) return ISuperLayerUtil::c_Invalid; // No next super layer to go to
  if (iSuperLayer == minimalISuperLayer) return ISuperLayerUtil::getNextOutwards(iSuperLayer);
  if (iSuperLayer == maximalISuperLayer) return ISuperLayerUtil::getNextInwards(iSuperLayer);
 
  if (movingOutward) {
    return ISuperLayerUtil::getNextOutwards(iSuperLayer);
  } else {
    return ISuperLayerUtil::getNextInwards(iSuperLayer);
  }
}

getISuperLayerAfterStart() [1/2]

ISuperLayer getISuperLayerAfterStart ( bool movingOutward ) const

private

Returns which superlayer is traversed after the current one following the trajectory outward or inward as indicated by the boolean input.

Definition at line 196 of file CDCTrajectory2D.cc.

{
  ISuperLayer iSuperLayer = getStartISuperLayer();
  return getISuperLayerAfter(iSuperLayer, movingOutward);
}

getISuperLayerAfterStart() [2/2]

ISuperLayer getISuperLayerAfterStart ( EForwardBackward forwardBackwardInfo ) const

private

Indicates which superlayer is traversed after the current one following the trajectory forward or backward as indicated by the input.

Definition at line 202 of file CDCTrajectory2D.cc.

{
  bool movingOutward = isMovingOutward();
  if (forwardBackwardInfo == EForwardBackward::c_Backward) {
    movingOutward = not movingOutward;
  }
  return getISuperLayerAfterStart(movingOutward);
}

getLocalCircle()

const UncertainPerigeeCircle & getLocalCircle ( ) const

inline

Getter for the circle in local coordinates.

Definition at line 459 of file CDCTrajectory2D.h.

      {
        return m_localPerigeeCircle;
      }

getLocalCovariance()

double getLocalCovariance ( EPerigeeParameter iRow, EPerigeeParameter iCol ) const

inline

Getter for an individual element of the covariance matrix of the local helix parameters.

Definition at line 431 of file CDCTrajectory2D.h.

      {
        return getLocalCircle().covariance(iRow, iCol);
      }

getLocalOrigin()

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

inline

Getter for the origin of the local coordinate system.

Definition at line 501 of file CDCTrajectory2D.h.

      {
        return m_localOrigin;
      }

getLocalVariance()

double getLocalVariance ( EPerigeeParameter i ) const

inline

Getter for an individual diagonal element of the covariance matrix of the local helix parameters.

Definition at line 438 of file CDCTrajectory2D.h.

      {
        return getLocalCircle().variance(i);
      }

getMaximalCylindricalR()

double getMaximalCylindricalR ( ) const

inline

Getter for the maximal distance from the origin.

Definition at line 393 of file CDCTrajectory2D.h.

      {
        return std::fabs(getGlobalImpact() + 2 * getLocalCircle()->radius());
      }

getMaximalISuperLayer()

ISuperLayer getMaximalISuperLayer

(

)

const

Indicates the maximal superlayer the trajectory traverses.

Definition at line 250 of file CDCTrajectory2D.cc.

{
  double maximalCylindricalR = getMaximalCylindricalR();
  return CDCWireTopology::getInstance().getISuperLayerAtCylindricalR(maximalCylindricalR);
}

getMinimalCylindricalR()

double getMinimalCylindricalR ( ) const

inline

Getter for the minimal distance from the origin - same as absolute value of the impact parameter.

Definition at line 400 of file CDCTrajectory2D.h.

      {
        return std::fabs(getGlobalImpact());
      }

getMinimalISuperLayer()

ISuperLayer getMinimalISuperLayer

(

)

const

Indicates the minimal superlayer the trajectory traverses.

Definition at line 262 of file CDCTrajectory2D.cc.

{
  double minimalCylindricalR = getMinimalCylindricalR();
  return CDCWireTopology::getInstance().getISuperLayerAtCylindricalR(minimalCylindricalR);
}

getMom2DAtSupport() [1/2]

ROOT::Math::XYVector getMom2DAtSupport ( ) const

inline

Get the momentum at the support point of the trajectory.

Definition at line 307 of file CDCTrajectory2D.h.

      {
        return getFlightDirection2DAtSupport() * getAbsMom2D();
      }

getMom2DAtSupport() [2/2]

ROOT::Math::XYVector getMom2DAtSupport ( const double bZ ) const

inline

Get the momentum at the support point of the trajectory.

Definition at line 301 of file CDCTrajectory2D.h.

      {
        return getFlightDirection2DAtSupport() * getAbsMom2D(bZ);
      }

getNDF()

size_t getNDF ( ) const

inline

Getter for the number of degrees of freedom of the circle fit.

Definition at line 483 of file CDCTrajectory2D.h.

      {
        return getLocalCircle().ndf();
      }

getNextAxialISuperLayer()

ISuperLayer getNextAxialISuperLayer

(

)

const

Indicates which axial superlayer the trajectory traverses after the one, where the start point of the trajectory is located.

Definition at line 240 of file CDCTrajectory2D.cc.

{
  return getAxialISuperLayerAfterStart(EForwardBackward::c_Forward);
}

getNextISuperLayer()

ISuperLayer getNextISuperLayer

(

)

const

Indicates which superlayer the trajectory traverses after the one, where the start point of the trajectory is located.

Definition at line 211 of file CDCTrajectory2D.cc.

{
  return getISuperLayerAfterStart(EForwardBackward::c_Forward);
}

getOuterExit()

ROOT::Math::XYVector getOuterExit

(

double

factor = 1

)

const

Calculates the point where the trajectory meets the outer wall of the CDC.

This method returns the first point in forward flight direction from the start point of the trajectory where it meets the outer radius of the outer most layer. If the trajectory does not meet the CDC by the outer wall this will return ROOT::Math::XYVector(nan,nan) The factor can be used to virtually resize the CDC.

Definition at line 317 of file CDCTrajectory2D.cc.

{
  const CDCWireTopology& topology = CDCWireTopology::getInstance();
  const CDCWireLayer& outerMostLayer = topology.getWireLayers().back();
  double outerCylindricalR = outerMostLayer.getOuterCylindricalR() * factor;
 
  const ROOT::Math::XYVector support = getSupport();
  const PerigeeCircle globalCircle = getGlobalCircle();
  if (support.Mag2() > outerCylindricalR * outerCylindricalR) {
    // If we start outside of the volume of the CDC we want the trajectory to enter the CDC
    // and not stop at first intersection with the outer wall.
    // Therefore we take the outer exit that comes after the perigee.
    const ROOT::Math::XYVector perigee = globalCircle.perigee();
    return globalCircle.atCylindricalRForwardOf(perigee, outerCylindricalR);
 
  } else {
    return getGlobalCircle().atCylindricalRForwardOf(support, outerCylindricalR);
  }
}

getPos2DAtArcLength2D()

ROOT::Math::XYVector getPos2DAtArcLength2D ( double arcLength2D )

inline

Getter for the position at a given two dimensional arc length.

Definition at line 332 of file CDCTrajectory2D.h.

      {
        return getLocalOrigin() + getLocalCircle()->atArcLength(arcLength2D);
      }

getPreviousAxialISuperLayer()

ISuperLayer getPreviousAxialISuperLayer

(

)

const

Indicates which axial superlayer the trajectory traverses before the one, where the start point of the trajectory is located.

Definition at line 245 of file CDCTrajectory2D.cc.

{
  return getAxialISuperLayerAfterStart(EForwardBackward::c_Backward);
}

getPreviousISuperLayer()

ISuperLayer getPreviousISuperLayer

(

)

const

Indicates which superlayer the trajectory traverses before the one, where the start point of the trajectory is located.

Definition at line 216 of file CDCTrajectory2D.cc.

{
  return getISuperLayerAfterStart(EForwardBackward::c_Backward);
}

getPValue()

double getPValue ( ) const

inline

Getter for p-value.

Definition at line 465 of file CDCTrajectory2D.h.

      {
        return TMath::Prob(getChi2(), getNDF());
      }

getStartISuperLayer()

ISuperLayer getStartISuperLayer

(

)

const

Indicates the superlayer the trajectory starts in.

Definition at line 256 of file CDCTrajectory2D.cc.

{
  double startCylindricalR = getLocalOrigin().R();
  return CDCWireTopology::getInstance().getISuperLayerAtCylindricalR(startCylindricalR);
}

getSupport()

ROOT::Math::XYVector getSupport ( ) const

inline

Get the support point of the trajectory in global coordinates.

Definition at line 338 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->perigee() + getLocalOrigin();
      }

getTotalArcLength2D()

template<class AHits>

double getTotalArcLength2D ( const AHits & hits ) const

inline

Calculates the perpendicular travel distance from the first position of the hits to the last position of the hits.

Definition at line 247 of file CDCTrajectory2D.h.

      {
        ROOT::Math::XYVector frontRecoPos2D = hits.front().getRecoPos2D();
        ROOT::Math::XYVector backRecoPos2D = hits.back().getRecoPos2D();
        return calcArcLength2DBetween(frontRecoPos2D, backRecoPos2D);
      }

isCurler()

bool isCurler

(

double

factor = 1

)

const

Checks if the trajectory leaves the outer radius of the CDC times the given tolerance factor.

Definition at line 268 of file CDCTrajectory2D.cc.

{
  const CDCWireTopology& topology = CDCWireTopology::getInstance();
  return getMaximalCylindricalR() < factor * topology.getOuterCylindricalR();
}

isFitted()

bool isFitted

(

)

const

Checks if the circle is already set to a valid value.

Definition at line 83 of file CDCTrajectory2D.cc.

{
  return not getLocalCircle()->isInvalid();
}

isForwardOrBackwardTo()

template<class AHits>

EForwardBackward isForwardOrBackwardTo ( const AHits & hits ) const

inline

Calculates if this trajectory and the hits are coaligned Returns:

• EForwardBackward::c_Forward if the last entity lies behind the first.
• EForwardBackward::c_Backward if the last entity lies before the first.

Definition at line 203 of file CDCTrajectory2D.h.

      {
        return static_cast<EForwardBackward>(sign(getTotalArcLength2D(hits)));
      }

isMovingOutward()

bool isMovingOutward ( ) const

inline

Indicates if the trajectory is moving outwards or inwards (to or away from the origin) from the start point on.

Definition at line 326 of file CDCTrajectory2D.h.

      {
        return getFlightDirection2DAtSupport().Dot(getSupport()) > 0;
      }

isOriginer()

bool isOriginer

(

double

factor = 1

)

const

Checks if the trajectory intersects with the inner radius of the CDC time the given tolerance factor.

Definition at line 274 of file CDCTrajectory2D.cc.

{
  const CDCWireTopology& topology = CDCWireTopology::getInstance();
  return getMinimalCylindricalR() < factor * topology.getInnerCylindricalR();
}

isRightOrLeft()

ERightLeft isRightOrLeft ( const ROOT::Math::XYVector & point ) const

inline

Checks if the given point is to the right or to the left of the trajectory.

Definition at line 418 of file CDCTrajectory2D.h.

      {
        return getLocalCircle()->isRightOrLeft(point - getLocalOrigin());
      }

reconstruct3D()

ROOT::Math::XYZVector reconstruct3D	(	const CDC::WireLine &	wireLine,
		double	distance = 0.0,
		double	z = 0 ) const

Gives the one three dimensional positions within the CDC closest to the given z where the given drift circle on the wire line touches the trajectory.

This method makes the reconstruction of the z coordinate possible by using the skewness
stereo layer of the stereo wires. The point is determined such that it is at the (signed) distance to the wire line.

Parameters

wireLine	The geometrical wire line on which the hit is located-
distance	The desired distance from the wire line a.k.a. drift length
z	The expected value of z to which to closest solution should be selected.

Definition at line 164 of file CDCTrajectory2D.cc.

{
  const double recoZ = reconstructZ(wireLine, distance, z);
  const ROOT::Math::XYZVector recoWirePos2D = wireLine.sagPos3DAtZ(recoZ);
  const auto& tmp = getClosest(VectorUtil::getXYVector(recoWirePos2D));
  return ROOT::Math::XYZVector(tmp.X(), tmp.Y(), recoZ);
}

reconstructBoth3D()

std::array< ROOT::Math::XYZVector, 2 > reconstructBoth3D	(	const CDC::WireLine &	wireLine,
		double	distance = 0.0,
		double	z = 0 ) const

Gives the two three dimensional points where the drift circle touches the wire line.

Only works for the skew stereo wires.

Parameters

wireLine	The geometrical wire line on which the hit is located-
distance	The desired distance from the wire line a.k.a. drift length
z	The expected value of z to which to closest solution should be selected.

Definition at line 149 of file CDCTrajectory2D.cc.

{
  const std::array<double, 2> solutionsZ = reconstructBothZ(wireLine, distance, z);
 
  const ROOT::Math::XYZVector firstRecoWirePos3D = wireLine.sagPos3DAtZ(solutionsZ[0]);
  const ROOT::Math::XYZVector secondRecoWirePos3D = wireLine.sagPos3DAtZ(solutionsZ[1]);
  const auto& tmp1 = getClosest(VectorUtil::getXYVector(firstRecoWirePos3D));
  const auto& tmp2 = getClosest(VectorUtil::getXYVector(secondRecoWirePos3D));
  return {{{tmp1.X(), tmp1.Y(), firstRecoWirePos3D.z()},
      {tmp2.X(), tmp2.Y(), secondRecoWirePos3D.z()}
    }};
}

reconstructBothZ()

std::array< double, 2 > reconstructBothZ	(	const CDC::WireLine &	wireLine,
		double	distance = 0.0,
		double	z = 0 ) const

Gives the two z positions where the given drift circle on the wire line touches the trajectory.

Only works for the skew stereo wires

Parameters

wireLine	The geometrical wire line on which the hit is located-
distance	The desired distance from the wire line a.k.a. drift length
z	The expected value of z to which to closest solution should be selected.

Definition at line 109 of file CDCTrajectory2D.cc.

{
  ROOT::Math::XYVector globalPos2D = wireLine.sagPos2DAtZ(z);
  ROOT::Math::XYVector movePerZ = wireLine.sagMovePerZ(z);
 
  ROOT::Math::XYVector localPos2D = globalPos2D - getLocalOrigin();
  const PerigeeCircle& localCircle = getLocalCircle();
 
  double fastDistance = distance != 0.0 ? localCircle.fastDistance(distance) : 0.0;
 
  double c = localCircle.fastDistance(localPos2D) - fastDistance;
  double b = localCircle.gradient(localPos2D).Dot(movePerZ);
  double a = localCircle.n3() * movePerZ.Mag2();
 
  const std::pair<double, double> solutionsDeltaZ = solveQuadraticABC(a, b, c);
 
  // Put the solution of smaller deviation first
  const std::array<double, 2> solutionsZ{solutionsDeltaZ.second + z, solutionsDeltaZ.first + z};
  return solutionsZ;
}

reconstructZ()

double reconstructZ	(	const CDC::WireLine &	wireLine,
		double	distance = 0.0,
		double	z = 0 ) const

Gives the one z positions within the CDC closest to the given z where the given drift circle on the wire line touches the trajectory.

Only works for the skew stereo wires.

Parameters

wireLine	The geometrical wire line on which the hit is located-
distance	The desired distance from the wire line a.k.a. drift length
z	The expected value of z to which to closest solution should be selected.

Definition at line 132 of file CDCTrajectory2D.cc.

{
  const std::array<double, 2> solutionsZ = reconstructBothZ(wireLine, distance, z);
 
  bool firstIsInCDC = (wireLine.backwardZ() < solutionsZ[0] and
                       solutionsZ[0] < wireLine.forwardZ());
  bool secondIsInCDC = (wireLine.backwardZ() < solutionsZ[1] and
                        solutionsZ[1] < wireLine.forwardZ());
 
  // Prefer the solution with the smaller deviation from the given z position which is the first
  assert(not(std::fabs(solutionsZ[0] - z) > std::fabs(solutionsZ[1] - z)));
  const double recoZ = (firstIsInCDC or not secondIsInCDC) ? solutionsZ[0] : solutionsZ[1];
  return recoZ;
}

reverse()

void reverse

(

)

Reverses the trajectory in place.

Definition at line 95 of file CDCTrajectory2D.cc.

{
  m_localPerigeeCircle.reverse();
  m_flightTime = -m_flightTime;
}

reversed()

CDCTrajectory2D reversed

(

)

const

Returns the reverse trajectory as a copy.

Definition at line 102 of file CDCTrajectory2D.cc.

{
  CDCTrajectory2D result = *this;
  result.reverse();
  return result;
}

setChi2()

void setChi2 ( const double chi2 )

inline

Setter for the chi square value of the circle fit.

Definition at line 477 of file CDCTrajectory2D.h.

      {
        return m_localPerigeeCircle.setChi2(chi2);
      }

setFlightTime()

void setFlightTime ( double flightTime )

inline

Setter for the time when the particle reached the support point position.

Definition at line 531 of file CDCTrajectory2D.h.

      {
        m_flightTime = flightTime;
      }

setGlobalCircle()

void setGlobalCircle ( const UncertainPerigeeCircle & perigeeCircle )

inline

Setter for the generalized circle that describes the trajectory.

Definition at line 452 of file CDCTrajectory2D.h.

      {
        m_localPerigeeCircle = perigeeCircle;
        m_localPerigeeCircle.passiveMoveBy(getLocalOrigin());
      }

setLocalCircle()

void setLocalCircle ( const UncertainPerigeeCircle & localPerigeeCircle )

inline

Setter for the generalized circle that describes the trajectory.

Definition at line 495 of file CDCTrajectory2D.h.

      {
        m_localPerigeeCircle = localPerigeeCircle;
      }

setLocalOrigin()

double setLocalOrigin

(

const ROOT::Math::XYVector &

localOrigin

)

Setter for the origin of the local coordinate system.

This sets the origin point the local circle representation is subjected. The local circle is also changed such that the set of points in global space is not changed on repositioning the local parameterisation. It also implicitly sets up a new reference position for all travel distances.
To be able to keep track how the travel distances have to be shifted by this change
the setter returns the value by which the coordinate s parameter was moved ( passively ).
The relation "old traveldistance - return value == new traveldistance" holds.
(if they are not to far away from the reference points, up to the discontinuity at the
far point on the circle)

Parameters

localOrigin

New local reference point in the global coordinate system

Returns

Travel distance from the old to the new origin point

Definition at line 358 of file CDCTrajectory2D.cc.

{
  double arcLength2D = calcArcLength2D(localOrigin);
  m_flightTime += arcLength2D / Const::speedOfLight;
  m_localPerigeeCircle.passiveMoveBy(localOrigin - m_localOrigin);
  m_localOrigin = localOrigin;
  return arcLength2D;
}

setNDF()

void setNDF ( std::size_t ndf )

inline

Setter for the number of degrees of freedom of the circle fit.

Definition at line 489 of file CDCTrajectory2D.h.

      {
        return m_localPerigeeCircle.setNDF(ndf);
      }

setPosMom2D()

void setPosMom2D	(	const ROOT::Math::XYVector &	pos2D,
		const ROOT::Math::XYVector &	mom2D,
		double	charge )

Setter for start point and momentum at the start point subjected to the charge sign.

Definition at line 347 of file CDCTrajectory2D.cc.

{
  m_localOrigin = pos2D;
  double curvature = CDCBFieldUtil::absMom2DToCurvature(mom2D.R(), charge, pos2D);
  ROOT::Math::XYVector phiVec = VectorUtil::unit(mom2D);
  double impact = 0.0;
  m_localPerigeeCircle = UncertainPerigeeCircle(curvature, phiVec, impact);
}

Member Data Documentation

m_flightTime

double m_flightTime = NAN

private

Memory for the estimation of the time at which the particle arrived at the support point.

Definition at line 544 of file CDCTrajectory2D.h.

m_localOrigin

ROOT::Math::XYVector m_localOrigin

private

Memory for local coordinate origin of the circle representing the trajectory in global coordinates.

Definition at line 538 of file CDCTrajectory2D.h.

m_localPerigeeCircle

UncertainPerigeeCircle m_localPerigeeCircle

private

Memory for the generalized circle describing the trajectory in coordinates from the local origin.

Definition at line 541 of file CDCTrajectory2D.h.

---

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

• tracking/trackingUtilities/eventdata/trajectories/include/CDCTrajectory2D.h
• tracking/trackingUtilities/eventdata/trajectories/src/CDCTrajectory2D.cc