CDCTrajectory3D Class Reference

Particle full three dimensional trajectory. More...

#include <CDCTrajectory3D.h>

Public Member Functions
	CDCTrajectory3D ()
	Default constructor for ROOT compatibility.
	CDCTrajectory3D (const UncertainHelix &helix)
	Constructs a trajectory from a helix with reference point equivalent to the origin.
	CDCTrajectory3D (const Helix &helix)
	conversion constructor to make that one stupid test work
	CDCTrajectory3D (const ROOT::Math::XYZVector &localOrigin, const UncertainHelix &localHelix, double flightTime=NAN)
	Constructs a trajectory from a local helix taken as relative to the given origin.
	CDCTrajectory3D (const CDCTrajectory2D &trajectory2D, const CDCTrajectorySZ &trajectorySZ)
	Construct a three dimensional trajectory from a two dimensional circular trajectory and sz linear trajectory.
	CDCTrajectory3D (const CDCTrajectory2D &trajectory2D)
	Construct a trajectory from a two dimensional circular trajectory filling the remaining two parameters and covariance matrix with default values.
	CDCTrajectory3D (const ROOT::Math::XYZVector &pos3D, double time, const ROOT::Math::XYZVector &mom3D, double charge, double bZ)
	Construct a trajectory with given start point, momentum at the start point and given charge.
	CDCTrajectory3D (const ROOT::Math::XYZVector &pos3D, double time, const ROOT::Math::XYZVector &mom3D, double charge)
	Construct a trajectory with given start point, momentum at the start point and given charge.
	CDCTrajectory3D (const MCParticle &mcParticle, double bZ)
	Construct a trajectory from the MCParticles vertex and momentum.
	CDCTrajectory3D (const MCParticle &mcParticle)
	Construct a trajectory from the MCParticles vertex and momentum.
	CDCTrajectory3D (const genfit::TrackCand &gfTrackCand, double bZ)
	Construct a trajectory by extracting the seed position of the genfit::TrackCand.
	CDCTrajectory3D (const genfit::TrackCand &gfTrackCand)
	Construct a trajectory by extracting the seed position of the genfit::TrackCand.
bool	isInvalid () const
	Checks if the trajectory is already set to a valid value.
bool	isFitted () const
	Checks if the trajectory has already been set to a valid value.
void	clear ()
	Clears all information from this trajectoy.
bool	fillInto (genfit::TrackCand &trackCand) const
	Copies the trajectory information to the Genfit track candidate.
bool	fillInto (genfit::TrackCand &gfTrackCand, double bZ) const
	Copies the trajectory information to the Genfit track candidate.
CovarianceMatrix< 6 >	getCartesianCovariance (double bZ) const
	Convert the helix parameters to the cartesian coordinates x,y,z,px,py,pz.
void	reverse ()
	Reverses the trajectory in place.
CDCTrajectory3D	reversed () const
	Returns the reverse trajectory as a copy.
ROOT::Math::XYZVector	reconstruct3D (const CDC::WireLine &wireLine, double distance=0.0) const
	Gives the three dimensional point which is on the dirft circle away from the wire line.
double	calcArcLength2D (const ROOT::Math::XYZVector &point) const
	Calculate the travel distance from the start position of the trajectory.
double	getArcLength2DPeriod () const
	Getter for the arc length for one round trip around the trajectory.
double	shiftPeriod (int nPeriods)
	Adjusts the z0 to the one that lies n periods forward.
ESign	getChargeSign () const
	Gets the charge sign of the trajectory.
double	getAbsMom3D (double bZ) const
	Get the estimation for the absolute value of the transvers momentum.
double	getAbsMom3D () const
	Get the estimation for the absolute value of the transvers momentum.
ROOT::Math::XYZVector	getMom3DAtSupport (const double bZ) const
	Get the momentum at the start point of the trajectory.
ROOT::Math::XYZVector	getMom3DAtSupport () const
	Get the momentum at the start point of the trajectory.
ROOT::Math::XYZVector	getFlightDirection3DAtSupport () const
	Get the unit momentum at the start point of the trajectory.
ROOT::Math::XYZVector	getSupport () const
	Getter for the support point of the trajectory in global coordinates, where arcLength2D = 0.
ROOT::Math::XYZVector	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 helix in global coordinates.
bool	isCurler (double factor=1) const
	Checks if the trajectory leaves the outer radius of the CDC times 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.
double	getGlobalImpact () const
	Getter for the signed impact parameter of the trajectory.
CDCTrajectory2D	getTrajectory2D () const
	Getter for the two dimensional trajectory.
CDCTrajectorySZ	getTrajectorySZ () const
	Getter for the sz trajectory.
PerigeeCircle	getGlobalCircle () const
	Getter for the circle in global coordinates.
UncertainPerigeeCircle	getLocalCircle () const
	Getter for the circle in local coordinates.
UncertainSZLine	getLocalSZLine () const
	Getter for the sz line starting from the local origin.
double	getLocalCovariance (EHelixParameter iRow, EHelixParameter iCol) const
	Getter for an individual element of the covariance matrix of the local helix parameters.
double	getLocalVariance (EHelixParameter i) const
	Getter for an individual diagonal element of the covariance matrix of the local helix parameters.
double	getTanLambda () const
	Getter for the slope of z over the transverse travel distance s.
double	getCurvatureXY () const
	Getter for the curvature as seen from the xy projection.
double	getPValue () const
	Getter for p-value.
double	getChi2 () const
	Getter for the chi2 value of the fit.
void	setChi2 (const double chi2)
	Setter for the chi square value of the helix fit.
size_t	getNDF () const
	Getter for the number of degrees of freedom of the helix fit.
void	setNDF (std::size_t ndf)
	Setter for the number of degrees of freedom of the helix fit.
const UncertainHelix &	getLocalHelix () const
	Getter for the helix in local coordinates.
void	setLocalHelix (const UncertainHelix &localHelix)
	Setter for the helix that describes the trajectory in local coordinates.
const ROOT::Math::XYZVector &	getLocalOrigin () const
	Getter for the origin of the local coordinate system.
double	setLocalOrigin (const ROOT::Math::XYZVector &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 Attributes
ROOT::Math::XYZVector	m_localOrigin
	Memory for local coordinate origin of the circle representing the trajectory in global coordinates.
UncertainHelix	m_localHelix
	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 full three dimensional trajectory.

Definition at line 46 of file CDCTrajectory3D.h.

Constructor & Destructor Documentation

CDCTrajectory3D() [1/12]

CDCTrajectory3D ( )

inline

Default constructor for ROOT compatibility.

Definition at line 50 of file CDCTrajectory3D.h.

        : m_localOrigin()
        , m_localHelix()
      {
      }

CDCTrajectory3D() [2/12]

CDCTrajectory3D ( const UncertainHelix & helix )

inlineexplicit

Constructs a trajectory from a helix with reference point equivalent to the origin.

Definition at line 57 of file CDCTrajectory3D.h.

        : m_localOrigin(0.0, 0.0, 0.0)
        , m_localHelix(helix)
        , m_flightTime(0.0)
      {
      }

CDCTrajectory3D() [3/12]

CDCTrajectory3D ( const Helix & helix )

inlineexplicit

conversion constructor to make that one stupid test work

Definition at line 65 of file CDCTrajectory3D.h.

                                                   : CDCTrajectory3D(UncertainHelix(helix))
      {
      }

CDCTrajectory3D() [4/12]

CDCTrajectory3D ( const ROOT::Math::XYZVector & localOrigin, const UncertainHelix & localHelix, double flightTime = NAN )

inline

Constructs a trajectory from a local helix taken as relative to the given origin.

Definition at line 70 of file CDCTrajectory3D.h.

        : m_localOrigin(localOrigin)
        , m_localHelix(localHelix)
        , m_flightTime(flightTime)
      {
      }

CDCTrajectory3D() [5/12]

CDCTrajectory3D	(	const CDCTrajectory2D &	trajectory2D,
		const CDCTrajectorySZ &	trajectorySZ )

Construct a three dimensional trajectory from a two dimensional circular trajectory and sz linear trajectory.

Definition at line 48 of file CDCTrajectory3D.cc.

  : m_localHelix(trajectory2D.getLocalCircle(), trajectorySZ.getSZLine())
  , m_flightTime(trajectory2D.getFlightTime())
{
  const auto& tmp = trajectory2D.getLocalOrigin();
  m_localOrigin = ROOT::Math::XYZVector(tmp.X(), tmp.Y(), 0.0);
}

CDCTrajectory3D() [6/12]

CDCTrajectory3D ( const CDCTrajectory2D & trajectory2D )

explicit

Construct a trajectory from a two dimensional circular trajectory filling the remaining two parameters and covariance matrix with default values.

Definition at line 57 of file CDCTrajectory3D.cc.

  : CDCTrajectory3D(trajectory2D, CDCTrajectorySZ::basicAssumption())
{
}

CDCTrajectory3D() [7/12]

CDCTrajectory3D	(	const ROOT::Math::XYZVector &	pos3D,
		double	time,
		const ROOT::Math::XYZVector &	mom3D,
		double	charge,
		double	bZ )

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

Additionally this can takes an explicit bZ value instead of a field value from the instance BFieldMap.

Definition at line 62 of file CDCTrajectory3D.cc.

  : m_localOrigin(pos3D)
  , m_localHelix(CDCBFieldUtil::absMom2DToCurvature(mom3D.Rho(), charge, bZ),
                 VectorUtil::unit(VectorUtil::getXYVector(mom3D)),
                 0.0,
                 (mom3D.Z() / mom3D.Rho()), // double cotTheta() const { return z() / Rho(); }
                 0.0)
  , m_flightTime(time)
{
}

CDCTrajectory3D() [8/12]

CDCTrajectory3D	(	const ROOT::Math::XYZVector &	pos3D,
		double	time,
		const ROOT::Math::XYZVector &	mom3D,
		double	charge )

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

Definition at line 77 of file CDCTrajectory3D.cc.

  : CDCTrajectory3D(pos3D, time, mom3D, charge, CDCBFieldUtil::getBFieldZ(pos3D))
{
}

CDCTrajectory3D() [9/12]

CDCTrajectory3D	(	const MCParticle &	mcParticle,
		double	bZ )

Construct a trajectory from the MCParticles vertex and momentum.

Definition at line 85 of file CDCTrajectory3D.cc.

  : CDCTrajectory3D(ROOT::Math::XYZVector{mcParticle.getProductionVertex()},
                    mcParticle.getProductionTime(),
                    ROOT::Math::XYZVector{mcParticle.getMomentum()},
                    mcParticle.getCharge(),
                    bZ)
{
}

CDCTrajectory3D() [10/12]

CDCTrajectory3D ( const MCParticle & mcParticle )

explicit

Construct a trajectory from the MCParticles vertex and momentum.

Definition at line 94 of file CDCTrajectory3D.cc.

  : CDCTrajectory3D(ROOT::Math::XYZVector{mcParticle.getProductionVertex()},
                    mcParticle.getProductionTime(),
                    ROOT::Math::XYZVector{mcParticle.getMomentum()},
                    mcParticle.getCharge())
{
}

CDCTrajectory3D() [11/12]

CDCTrajectory3D	(	const genfit::TrackCand &	gfTrackCand,
		double	bZ )

Construct a trajectory by extracting the seed position of the genfit::TrackCand.

Definition at line 102 of file CDCTrajectory3D.cc.

  : CDCTrajectory3D(ROOT::Math::XYZVector{gfTrackCand.getPosSeed()},
                    gfTrackCand.getTimeSeed(),
                    ROOT::Math::XYZVector{gfTrackCand.getMomSeed()},
                    gfTrackCand.getChargeSeed(),
                    bZ)
{
  // Maybe push these out of this function:
  // Indices of the cartesian coordinates
  const int iX = 0;
  const int iY = 1;
  const int iZ = 2;
  const int iPx = 3;
  const int iPy = 4;
  const int iPz = 5;
 
  const TMatrixDSym& seedCov = gfTrackCand.getCovSeed();
  CovarianceMatrix<6> cov6 = TMatrixConversion::fromTMatrix<6>(seedCov);
 
  // 1. Rotate to a system where phi0 = 0
  JacobianMatrix<6, 6> jacobianRot = JacobianMatrixUtil::zero<6, 6>();
 
  const double px = gfTrackCand.getStateSeed()[iPx];
  const double py = gfTrackCand.getStateSeed()[iPy];
  const double pt = hypot2(px, py);
 
  const double cosPhi0 = px / pt;
  const double sinPhi0 = py / pt;
 
  // Passive rotation matrix by phi0:
  jacobianRot(iX, iX) = cosPhi0;
  jacobianRot(iX, iY) = sinPhi0;
  jacobianRot(iY, iX) = -sinPhi0;
  jacobianRot(iY, iY) = cosPhi0;
  jacobianRot(iZ, iZ) = 1.0;
 
  jacobianRot(iPx, iPx) = cosPhi0;
  jacobianRot(iPx, iPy) = sinPhi0;
  jacobianRot(iPy, iPx) = -sinPhi0;
  jacobianRot(iPy, iPy) = cosPhi0;
  jacobianRot(iPz, iPz) = 1.0;
 
  // Apply transformation inplace
  CovarianceMatrixUtil::transport(jacobianRot, cov6);
 
  // 2. Translate to perigee parameters
  JacobianMatrix<5, 6> jacobianReduce = JacobianMatrixUtil::zero<5, 6>();
 
  const double invPt = 1 / pt;
  const double invPtSquared = invPt * invPt;
  const double pz = gfTrackCand.getStateSeed()[iPz];
  const double alpha = CDCBFieldUtil::getAlphaFromBField(bZ);
  const double charge = gfTrackCand.getChargeSeed();
 
  using namespace NHelixParameterIndices;
  jacobianReduce(c_Curv, iPx) = charge * invPtSquared / alpha ;
  jacobianReduce(c_Phi0, iPy) = invPt;
  jacobianReduce(c_I, iY) = 1;
  jacobianReduce(c_TanL, iPx) = - pz * invPtSquared;
  jacobianReduce(c_TanL, iPz) = invPt;
  jacobianReduce(c_Z0, iZ) = 1;
  // Note the column corresponding to iX is completely zero as expectable.
 
  CovarianceMatrix<5> cov5 = CovarianceMatrixUtil::transported(jacobianReduce, cov6);
  const HelixCovariance& helixCovariance = cov5;
 
  // The covariance should now be the correct 5x5 covariance matrix.
  m_localHelix.setHelixCovariance(helixCovariance);
}

CDCTrajectory3D() [12/12]

CDCTrajectory3D ( const genfit::TrackCand & gfTrackCand )

explicit

Construct a trajectory by extracting the seed position of the genfit::TrackCand.

Definition at line 172 of file CDCTrajectory3D.cc.

  : CDCTrajectory3D(gfTrackCand, CDCBFieldUtil::getBFieldZ(ROOT::Math::XYZVector{gfTrackCand.getPosSeed()}))
{
}

Member Function Documentation

calcArcLength2D()

double calcArcLength2D ( const ROOT::Math::XYZVector & 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 179 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->circleXY().arcLengthTo(VectorUtil::getXYVector(point - getLocalOrigin()));
      }

clear()

void clear ( )

inline

Clears all information from this trajectoy.

Definition at line 131 of file CDCTrajectory3D.h.

      {
        m_localOrigin.SetXYZ(0.0, 0.0, 0.0);
        m_localHelix.invalidate();
        m_flightTime = NAN;
      }

fillInto() [1/2]

bool fillInto	(	genfit::TrackCand &	gfTrackCand,
		double	bZ ) const

Copies the trajectory information to the Genfit track candidate.

Definition at line 268 of file CDCTrajectory3D.cc.

{
  // Set the start parameters
  ROOT::Math::XYZVector position = getSupport();
  ROOT::Math::XYZVector momentum = bZ == 0 ? getFlightDirection3DAtSupport() : getMom3DAtSupport(bZ);
  ESign charge = getChargeSign();
 
  // Do not propagate invalid fits, signal that the fit is invalid to the caller.
  if (not ESignUtil::isValid(charge) or VectorUtil::hasNAN(momentum) or VectorUtil::hasNAN(position)) {
    return false;
  }
 
  gfTrackCand.setPosMomSeed(XYZToTVector(position), XYZToTVector(momentum), charge);
 
  const CovarianceMatrix<6> cov6 = calculateCovarianceMatrix(getLocalHelix(), momentum, charge, bZ);
  TMatrixDSym covSeed = TMatrixConversion::toTMatrix(cov6);
 
  gfTrackCand.setCovSeed(covSeed);
 
  return true;
}

fillInto() [2/2]

bool fillInto

(

genfit::TrackCand &

trackCand

)

const

Copies the trajectory information to the Genfit track candidate.

Definition at line 262 of file CDCTrajectory3D.cc.

{
  ROOT::Math::XYZVector position = getSupport();
  return fillInto(trackCand, CDCBFieldUtil::getBFieldZ(position));
}

getAbsMom3D() [1/2]

double getAbsMom3D

(

)

const

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

Definition at line 318 of file CDCTrajectory3D.cc.

{
  ROOT::Math::XYZVector position = getSupport();
  double tanLambda = getLocalHelix()->tanLambda();
  double factor2DTo3D = hypot2(1, tanLambda);
  double curvatureXY = getLocalHelix()->curvatureXY();
  double absMom2D = CDCBFieldUtil::curvatureToAbsMom2D(curvatureXY, position);
  return factor2DTo3D * absMom2D;
}

getAbsMom3D() [2/2]

double getAbsMom3D

(

double

bZ

)

const

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

Definition at line 309 of file CDCTrajectory3D.cc.

{
  double tanLambda = getLocalHelix()->tanLambda();
  double factor2DTo3D = hypot2(1, tanLambda);
  double curvatureXY = getLocalHelix()->curvatureXY();
  double absMom2D = CDCBFieldUtil::curvatureToAbsMom2D(curvatureXY, bZ);
  return factor2DTo3D * absMom2D;
}

getArcLength2DPeriod()

double getArcLength2DPeriod ( ) const

inline

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

Definition at line 185 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->arcLength2DPeriod();
      }

getCartesianCovariance()

CovarianceMatrix< 6 > getCartesianCovariance

(

double

bZ

)

const

Convert the helix parameters to the cartesian coordinates x,y,z,px,py,pz.

Definition at line 290 of file CDCTrajectory3D.cc.

{
  // Set the start parameters
  ROOT::Math::XYZVector momentum = bZ == 0 ? getFlightDirection3DAtSupport() : getMom3DAtSupport(bZ);
  ESign charge = getChargeSign();
  return calculateCovarianceMatrix(getLocalHelix(), momentum, charge, bZ);
}

getChargeSign()

ESign getChargeSign

(

)

const

Gets the charge sign of the trajectory.

Definition at line 304 of file CDCTrajectory3D.cc.

{
  return CDCBFieldUtil::ccwInfoToChargeSign(getLocalHelix()->circleXY().orientation());
}

getChi2()

double getChi2 ( ) const

inline

Getter for the chi2 value of the fit.

Definition at line 316 of file CDCTrajectory3D.h.

      {
        return getLocalHelix().chi2();
      }

getCurvatureXY()

double getCurvatureXY ( ) const

inline

Getter for the curvature as seen from the xy projection.

Definition at line 304 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->curvatureXY();
      }

getFlightDirection3DAtSupport()

ROOT::Math::XYZVector getFlightDirection3DAtSupport ( ) const

inline

Get the unit momentum at the start point of the trajectory.

Definition at line 221 of file CDCTrajectory3D.h.

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

getFlightTime()

double getFlightTime ( ) const

inline

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

Definition at line 365 of file CDCTrajectory3D.h.

      {
        return m_flightTime;
      }

getGlobalCenter()

ROOT::Math::XYVector getGlobalCenter ( ) const

inline

Getter for the center of the helix in global coordinates.

Definition at line 240 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->centerXY() + VectorUtil::getXYVector(m_localOrigin);
      }

getGlobalCircle()

PerigeeCircle getGlobalCircle

(

)

const

Getter for the circle in global coordinates.

Definition at line 350 of file CDCTrajectory3D.cc.

{
  // Down cast since we do not necessarily won't the covariance matrix transformed as well
  PerigeeCircle result(getLocalHelix()->circleXY());
  result.passiveMoveBy(-VectorUtil::getXYVector(getLocalOrigin()));
  return result;
}

getGlobalImpact()

double getGlobalImpact ( ) const

inline

Getter for the signed impact parameter of the trajectory.

Definition at line 263 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->distanceXY(-VectorUtil::getXYVector(m_localOrigin));
      }

getGlobalPerigee()

ROOT::Math::XYZVector getGlobalPerigee ( ) const

inline

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

Definition at line 234 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->closestXY(-VectorUtil::getXYVector(m_localOrigin)) + m_localOrigin;
      }

getLocalCircle()

UncertainPerigeeCircle getLocalCircle

(

)

const

Getter for the circle in local coordinates.

Definition at line 358 of file CDCTrajectory3D.cc.

{
  return getLocalHelix().uncertainCircleXY();
}

getLocalCovariance()

double getLocalCovariance ( EHelixParameter iRow, EHelixParameter iCol ) const

inline

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

Definition at line 285 of file CDCTrajectory3D.h.

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

getLocalHelix()

const UncertainHelix & getLocalHelix ( ) const

inline

Getter for the helix in local coordinates.

Definition at line 340 of file CDCTrajectory3D.h.

      {
        return m_localHelix;
      }

getLocalOrigin()

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

inline

Getter for the origin of the local coordinate system.

Definition at line 352 of file CDCTrajectory3D.h.

      {
        return m_localOrigin;
      }

getLocalSZLine()

UncertainSZLine getLocalSZLine

(

)

const

Getter for the sz line starting from the local origin.

Definition at line 363 of file CDCTrajectory3D.cc.

{
  return getLocalHelix().uncertainSZLine();
}

getLocalVariance()

double getLocalVariance ( EHelixParameter i ) const

inline

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

Definition at line 292 of file CDCTrajectory3D.h.

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

getMaximalCylindricalR()

double getMaximalCylindricalR ( ) const

inline

Getter for the maximal distance from the origin.

Definition at line 251 of file CDCTrajectory3D.h.

      {
        return std::fabs(getGlobalImpact() + 2 * getLocalHelix()->radiusXY());
      }

getMinimalCylindricalR()

double getMinimalCylindricalR ( ) const

inline

Getter for the minimal distance from the origin.

Definition at line 257 of file CDCTrajectory3D.h.

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

getMom3DAtSupport() [1/2]

ROOT::Math::XYZVector getMom3DAtSupport ( ) const

inline

Get the momentum at the start point of the trajectory.

Definition at line 215 of file CDCTrajectory3D.h.

      {
        return getFlightDirection3DAtSupport() * getAbsMom3D();
      }

getMom3DAtSupport() [2/2]

ROOT::Math::XYZVector getMom3DAtSupport ( const double bZ ) const

inline

Get the momentum at the start point of the trajectory.

Definition at line 209 of file CDCTrajectory3D.h.

      {
        return getFlightDirection3DAtSupport() * getAbsMom3D(bZ);
      }

getNDF()

size_t getNDF ( ) const

inline

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

Definition at line 328 of file CDCTrajectory3D.h.

      {
        return getLocalHelix().ndf();
      }

getPValue()

double getPValue ( ) const

inline

Getter for p-value.

Definition at line 310 of file CDCTrajectory3D.h.

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

getSupport()

ROOT::Math::XYZVector getSupport ( ) const

inline

Getter for the support point of the trajectory in global coordinates, where arcLength2D = 0.

Definition at line 228 of file CDCTrajectory3D.h.

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

getTanLambda()

double getTanLambda ( ) const

inline

Getter for the slope of z over the transverse travel distance s.

Definition at line 298 of file CDCTrajectory3D.h.

      {
        return getLocalHelix()->tanLambda();
      }

getTrajectory2D()

CDCTrajectory2D getTrajectory2D

(

)

const

Getter for the two dimensional trajectory.

Definition at line 335 of file CDCTrajectory3D.cc.

{
  return CDCTrajectory2D(VectorUtil::getXYVector(getLocalOrigin()),
                         getLocalHelix().uncertainCircleXY(),
                         getFlightTime());
}

getTrajectorySZ()

CDCTrajectorySZ getTrajectorySZ

(

)

const

Getter for the sz trajectory.

Definition at line 342 of file CDCTrajectory3D.cc.

{
  UncertainSZLine globalSZLine = getLocalHelix().uncertainSZLine();
  globalSZLine.passiveMoveBy(ROOT::Math::XYVector(0, -getLocalOrigin().z()));
  return CDCTrajectorySZ(globalSZLine);
}

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 298 of file CDCTrajectory3D.cc.

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

isFitted()

bool isFitted ( ) const

inline

Checks if the trajectory has already been set to a valid value.

Definition at line 125 of file CDCTrajectory3D.h.

      {
        return not isInvalid();
      }

isInvalid()

bool isInvalid ( ) const

inline

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

Definition at line 119 of file CDCTrajectory3D.h.

      {
        return m_localHelix->isInvalid();
      }

reconstruct3D()

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

Gives the three dimensional point which is on the dirft circle away from the wire line.

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.

reverse()

void reverse ( )

inline

Reverses the trajectory in place.

Definition at line 150 of file CDCTrajectory3D.h.

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

reversed()

CDCTrajectory3D reversed ( ) const

inline

Returns the reverse trajectory as a copy.

Definition at line 157 of file CDCTrajectory3D.h.

      {
        return CDCTrajectory3D(getLocalOrigin(), getLocalHelix().reversed(), -getFlightTime());
      }

setChi2()

void setChi2 ( const double chi2 )

inline

Setter for the chi square value of the helix fit.

Definition at line 322 of file CDCTrajectory3D.h.

      {
        return m_localHelix.setChi2(chi2);
      }

setFlightTime()

void setFlightTime ( double flightTime )

inline

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

Definition at line 371 of file CDCTrajectory3D.h.

      {
        m_flightTime = flightTime;
      }

setLocalHelix()

void setLocalHelix ( const UncertainHelix & localHelix )

inline

Setter for the helix that describes the trajectory in local coordinates.

Definition at line 346 of file CDCTrajectory3D.h.

      {
        m_localHelix = localHelix;
      }

setLocalOrigin()

double setLocalOrigin

(

const ROOT::Math::XYZVector &

localOrigin

)

Setter for the origin of the local coordinate system.

This sets the origin point the local helix representation is subjected. The local helix is changed such that the set of points in global space is not changed.

Definition at line 368 of file CDCTrajectory3D.cc.

{
  double arcLength2D = calcArcLength2D(localOrigin);
  double factor2DTo3D = hypot2(1, getTanLambda());
  double arcLength3D = arcLength2D * factor2DTo3D;
  m_flightTime += arcLength3D / Const::speedOfLight;
  m_localHelix.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 helix fit.

Definition at line 334 of file CDCTrajectory3D.h.

      {
        return m_localHelix.setNDF(ndf);
      }

shiftPeriod()

double shiftPeriod

(

int

nPeriods

)

Adjusts the z0 to the one that lies n periods forward.

Returns

The two dimensional arc length needed to travel from the old to the new support point.

Definition at line 328 of file CDCTrajectory3D.cc.

{
  double arcLength2D = m_localHelix.shiftPeriod(nPeriods);
  m_flightTime += arcLength2D / Const::speedOfLight;
  return arcLength2D;
}

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 385 of file CDCTrajectory3D.h.

m_localHelix

UncertainHelix m_localHelix

private

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

Definition at line 382 of file CDCTrajectory3D.h.

m_localOrigin

ROOT::Math::XYZVector m_localOrigin

private

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

Definition at line 378 of file CDCTrajectory3D.h.

---

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

• tracking/trackingUtilities/eventdata/trajectories/include/CDCTrajectory3D.h
• tracking/trackingUtilities/eventdata/trajectories/src/CDCTrajectory3D.cc