New Track Event Model: TrackLinearExtrapolator Class Reference

00117   : TrackExtrapolator ( type, name, parent )
00118 {
00119   //declareInterface<ITrackExtrapolator>( this );
00120 }

00081 {
00082   // calculation of the z-position by linear extrapolation to the plane
00083   // ------------------------------------------------------------------
00084   // given the plane defined by (a,b,c,d) and the input state of
00085   // position (x0,y0,z0) and slopes (Tx,Ty),
00086   // the (x,y,z) of the intersection point verify the set of equations
00087   //    a*x + b*y + c*z + d = 0
00088   //    x = x0 + (z-z0)*Tx
00089   //    x = y0 + (z-z0)*Ty
00090   HepNormal3D nVec   = plane.normal();
00091   HepPoint3D  posVec = state.position();
00092   HepVector3D slpVec = state.slopes();
00093 
00094   double den = nVec.dot( slpVec );
00095 
00096   if ( den < TrackParameters::looseTolerance ) return StatusCode::FAILURE;
00097 
00098   slpVec *= ( state.z() );
00099   posVec -= slpVec;
00100   
00101   double nom = - ( nVec.dot( posVec ) + plane.d() );
00102   
00103   double zNew = nom / den;
00104 
00105   debug() << " z propagation " << zNew 
00106           << " of particle pid " << pid.pid() << endreq;
00107 
00108   return propagate( state, zNew, pid );
00109 }

00048 {
00049   // create transport matrix
00050   unsigned int ndim = state.nParameters();
00051   
00052   m_F = HepMatrix(ndim, ndim, 1);
00053 
00054   // check current z-position
00055   double dz = zNew - state.z();
00056   // if ( fabs(dz) < TrackParameters::hiTolerance ) dz = 0.;
00057   m_F[0][2] = dz; // tx*dz
00058   m_F[1][3] = dz; // ty*dz
00059 
00060   debug() << "Transport matrix F =" << m_F << endreq;
00061   
00062   // extrapolate
00063   //extrapolate(state);
00064   //state -> setZ( zNew );
00065   updateState( state, zNew );
00066 
00067   debug() << " z propagation " << zNew
00068           << " propagated state " << state.stateVector()
00069           << " propagated cov   " << state.covariance()
00070           << " of particle pid " << pid.pid() << endreq;
00071 
00072   return StatusCode::SUCCESS;
00073 }


Public Member Functions
	TrackLinearExtrapolator (const std::string &type, const std::string &name, const IInterface *parent)
	constructor
virtual	~TrackLinearExtrapolator ()
	destructor
StatusCode	propagate (State &state, double z, ParticleID pid=ParticleID(211))
	Propagate a State to a given z-position.
StatusCode	propagate (State &state, HepPlane3D &plane, ParticleID pid=ParticleID(211))
	Propagate a State to the intersection point with a given plane.

TrackLinearExtrapolator Class Reference

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation