#include <CurvilinearTrajectoryParameters.h>

Public Member Functions
TrackCharge	charge () const
	access to the charge
	CurvilinearTrajectoryParameters ()
	default constructor
	CurvilinearTrajectoryParameters (const GlobalPoint &aX, const GlobalVector &aP, TrackCharge aCharge)
	CurvilinearTrajectoryParameters (const AlgebraicVector5 &v, bool charged=true)
	CurvilinearTrajectoryParameters (double aQbp, double alambda, double aphi, double axT, double ayT, bool charged=true)
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
double	xT () const
double	yT () const
Private Attributes
double	thelambda
double	thephi
double	theQbp
double	thexT
double	theyT

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 28 of file CurvilinearTrajectoryParameters.h.

Constructor & Destructor Documentation

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters ( ) [inline]

default constructor

Definition at line 33 of file CurvilinearTrajectoryParameters.h.

{}

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	const AlgebraicVector5 &	v,
		bool	charged = `true`
	)		`[inline]`

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 42 of file CurvilinearTrajectoryParameters.h.

                                                                                  :
  theQbp(charged ? v[0] : 0), thelambda(v[1]), thephi(v[2]), thexT(v[3]), theyT(v[4]) {}

CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters	(	double	aQbp,
		double	alambda,
		double	aphi,
		double	axT,
		double	ayT,
		bool	charged = `true`
	)		`[inline]`

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 56 of file CurvilinearTrajectoryParameters.h.

                                                                                                                         :
    theQbp(charged ? aQbp : 0), thelambda(alambda), thephi(aphi), thexT(axT), theyT(ayT) {}

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

Constructor from a global vector, global point and track charge

Definition at line 5 of file CurvilinearTrajectoryParameters.cc.

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

{
 
  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);
}

Member Function Documentation

TrackCharge CurvilinearTrajectoryParameters::charge ( void ) const [inline]

access to the charge

Definition at line 66 of file CurvilinearTrajectoryParameters.h.

References Qbp().

{ return (0==Qbp()) ? 0 : ( Qbp()>0 ? 1 : -1) ;}

double CurvilinearTrajectoryParameters::lambda ( ) const [inline]

Definition at line 88 of file CurvilinearTrajectoryParameters.h.

References thelambda.

{   return thelambda;  }

double CurvilinearTrajectoryParameters::phi ( void ) const [inline]

Definition at line 89 of file CurvilinearTrajectoryParameters.h.

References thephi.

{    return thephi;  }

double CurvilinearTrajectoryParameters::Qbp ( ) const [inline]

Definition at line 87 of file CurvilinearTrajectoryParameters.h.

References theQbp.

Referenced by charge(), signedInverseMomentum(), and updateP().

{    return theQbp;  }

double CurvilinearTrajectoryParameters::signedInverseMomentum ( ) const [inline]

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

Definition at line 69 of file CurvilinearTrajectoryParameters.h.

References Qbp().

                                       {
    return  Qbp();
  }

bool CurvilinearTrajectoryParameters::updateP ( double dP )

Definition at line 19 of file CurvilinearTrajectoryParameters.cc.

References abs, AlCaHLTBitMon_ParallelJobs::p, Qbp(), and theQbp.

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

AlgebraicVector5 CurvilinearTrajectoryParameters::vector ( ) const [inline]

Vector of parameters with signed inverse momentum.

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

Definition at line 78 of file CurvilinearTrajectoryParameters.h.

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

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

double CurvilinearTrajectoryParameters::xT ( ) const [inline]

Definition at line 90 of file CurvilinearTrajectoryParameters.h.

References thexT.