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CurvilinearTrajectoryParameters Class Reference

Class providing access to a set of relevant parameters of a trajectory in a Curvilinear frame. More...

#include <TrackingTools/TrajectoryParametrization/interface/CurvilinearTrajectoryParameters.h>

List of all members.

Public Member Functions
TrackCharge	charge () const
	access to the charge
	CurvilinearTrajectoryParameters (const GlobalPoint &aX, const GlobalVector &aP, TrackCharge aCharge)
	Constructor from a global vector, global point and track charge.
	CurvilinearTrajectoryParameters (double aQbp, double alambda, double aphi, double axT, double ayT, bool charged=true)
	Constructor from vector of parameters Expects a vector of parameters as defined above.
	CurvilinearTrajectoryParameters (const AlgebraicVector5 &v, bool charged=true)
	Constructor from vector of parameters Expects a vector of parameters as defined above.
	CurvilinearTrajectoryParameters ()
	default constructor
double	lambda () const
double	phi () const
double	Qbp () const
double	signedInverseMomentum () const
	access to the Signed Inverse momentum q/p (zero for neutrals)
bool	updateP (double dP)
AlgebraicVector5	vector () const
	Vector of parameters with signed inverse momentum.
double	xT () const
double	yT () const
Private Attributes
TrackCharge	theCharge
double	thelambda
double	thephi
double	theQbp
double	thexT
double	theyT

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Detailed Description

Class providing access to a set of relevant parameters of a trajectory in a Curvilinear frame.

The set consists of the following paramters: \ q/p: charged particles: charge(plus or minus one) divided by magnitude of momentum neutral particles: inverse magnitude of momentum lambda: the helix dip angle (pi/2 minus theta(polar angle)), defined in the global frame phi: the angle of inclination with the global x-axis in the transverse (global xy) plane xT: transverse position in the global xy plane and it points left when looking into the direction of the track yT: transverse position that forms a right-handed frame with xT and zT

Note that the frame is tangent to the track at the point of definition, with Z_T parallel to the track

Definition at line 29 of file CurvilinearTrajectoryParameters.h.

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Constructor & Destructor Documentation

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters

(

)

[inline]

default constructor

Definition at line 34 of file CurvilinearTrajectoryParameters.h.

{}

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	const AlgebraicVector5 &	v,
		bool	charged = true
	)

Constructor from vector of parameters Expects a vector of parameters as defined above.

For charged particles he charge will be determined by\ the sign of the first element. For neutral particles the last argument should be false, in which case the charge of the first element will be neglected.

Definition at line 4 of file CurvilinearTrajectoryParameters.cc.

References theCharge, thelambda, thephi, theQbp, thexT, and theyT.

                                                                                                        {
  theQbp    = v[0];
  thelambda = v[1];
  thephi    = v[2];
  thexT     = v[3];
  theyT     = v[4];
  
  if ( charged )
    theCharge = theQbp>0 ? 1 : -1;
  else
    theCharge = 0;
  
}

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	double	aQbp,
		double	alambda,
		double	aphi,
		double	axT,
		double	ayT,
		bool	charged = true
	)

Constructor from vector of parameters Expects a vector of parameters as defined above.

For charged particles the charge will be determined by the sign of the first element. For neutral particles the last argument should be false, in which case the charge of the first element will be neglected.Constructor from individual curvilinear parameters Expects parameters as defined above.

Definition at line 19 of file CurvilinearTrajectoryParameters.cc.

References theCharge, and theQbp.

                                                                                                                                              : theQbp(aQbp), thelambda(alambda), thephi(aphi), thexT(axT), theyT(ayT) {
    
    if ( charged ) {
      theQbp = aQbp;
      theCharge = theQbp>0 ? 1 : -1;
    }
    else {
      theQbp = aQbp;
      theCharge = 0;
    }
}

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	const GlobalPoint &	aX,
		const GlobalVector &	aP,
		TrackCharge	aCharge
	)

Constructor from a global vector, global point and track charge.

Definition at line 32 of file CurvilinearTrajectoryParameters.cc.

References PV3DBase< T, PVType, FrameType >::mag(), funct::sqrt(), theCharge, thelambda, thephi, theQbp, thexT, theyT, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

{
  if(aCharge==0) 
    theQbp = 1./aP.mag();
  else
    theQbp=aCharge/aP.mag();

  double pT2= aP.x()*aP.x()+aP.y()*aP.y();
  double pT =sqrt(pT2);
  thelambda= atan(aP.z()/pT);
  thephi=atan2(aP.y(),aP.x());
  thexT= (-aP.y()*aX.x()+ aP.x()*aX.y()) / pT;
  theyT= (-aX.x()*aP.x()*aP.z() - aX.y()*aP.z()*aP.y() + aX.z()*(pT2))  / (aP.mag()*pT);
  theCharge=aCharge;
}

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Member Function Documentation

TrackCharge CurvilinearTrajectoryParameters::charge

(

void

)

const [inline]

access to the charge

Definition at line 65 of file CurvilinearTrajectoryParameters.h.

References theCharge.

Referenced by signedInverseMomentum().

{return theCharge;}

double CurvilinearTrajectoryParameters::lambda

(

)

const [inline]

Definition at line 81 of file CurvilinearTrajectoryParameters.h.

References thelambda.

{   return thelambda;  }

double CurvilinearTrajectoryParameters::phi

(

void

)

const [inline]

Definition at line 82 of file CurvilinearTrajectoryParameters.h.

References thephi.

{    return thephi;  }

double CurvilinearTrajectoryParameters::Qbp

(

)

const [inline]

Definition at line 80 of file CurvilinearTrajectoryParameters.h.

References theQbp.

{    return theQbp;  }

double CurvilinearTrajectoryParameters::signedInverseMomentum

(

)

const [inline]

access to the Signed Inverse momentum q/p (zero for neutrals)

Definition at line 68 of file CurvilinearTrajectoryParameters.h.

References charge(), and theQbp.

Referenced by vector().

                                       {
    return charge()==0 ? 0. : theQbp;
  }

bool CurvilinearTrajectoryParameters::updateP

(

double

dP

)

Definition at line 61 of file CurvilinearTrajectoryParameters.cc.

References p, and theQbp.

                                                       {
  //FIXME. something is very likely to be missing here
  double p = 1./fabs(theQbp);
  if ((p += dP) <= 0.) return false;
  double newQbp = theQbp > 0. ? 1./p : -1./p;
  theQbp = newQbp;
  return true;
}

AlgebraicVector5 CurvilinearTrajectoryParameters::vector

(

)

const

Vector of parameters with signed inverse momentum.

Vector of parameters as defined above, with the first element q/p.

Definition at line 51 of file CurvilinearTrajectoryParameters.cc.

References signedInverseMomentum(), thelambda, thephi, thexT, and theyT.

                                                               {
  return AlgebraicVector5(signedInverseMomentum(),
                          thelambda,
                          thephi,
                          thexT,
                          theyT);
}

double CurvilinearTrajectoryParameters::xT

(

)

const [inline]

Definition at line 83 of file CurvilinearTrajectoryParameters.h.

References thexT.

{   return thexT;  }

double CurvilinearTrajectoryParameters::yT

(

)

const [inline]

Definition at line 84 of file CurvilinearTrajectoryParameters.h.

References theyT.

{    return theyT;  }

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Member Data Documentation

TrackCharge CurvilinearTrajectoryParameters::theCharge [private]

Definition at line 95 of file CurvilinearTrajectoryParameters.h.

Referenced by charge(), and CurvilinearTrajectoryParameters().

double CurvilinearTrajectoryParameters::thelambda [private]

Definition at line 90 of file CurvilinearTrajectoryParameters.h.

Referenced by CurvilinearTrajectoryParameters(), lambda(), and vector().

double CurvilinearTrajectoryParameters::thephi [private]

Definition at line 91 of file CurvilinearTrajectoryParameters.h.

Referenced by CurvilinearTrajectoryParameters(), phi(), and vector().

double CurvilinearTrajectoryParameters::theQbp [private]

Definition at line 89 of file CurvilinearTrajectoryParameters.h.

Referenced by CurvilinearTrajectoryParameters(), Qbp(), signedInverseMomentum(), and updateP().

double CurvilinearTrajectoryParameters::thexT [private]

Definition at line 92 of file CurvilinearTrajectoryParameters.h.

Referenced by CurvilinearTrajectoryParameters(), vector(), and xT().

double CurvilinearTrajectoryParameters::theyT [private]

Definition at line 93 of file CurvilinearTrajectoryParameters.h.

Referenced by CurvilinearTrajectoryParameters(), vector(), and yT().

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

• TrackingTools/TrajectoryParametrization/interface/CurvilinearTrajectoryParameters.h
• TrackingTools/TrajectoryParametrization/src/CurvilinearTrajectoryParameters.cc

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