JacobianCartesianToLocal Class Reference

#include <JacobianCartesianToLocal.h>

Public Member Functions
const AlgebraicMatrix56 &	jacobian () const
	JacobianCartesianToLocal (const Surface &surface, const LocalTrajectoryParameters &localParameters)

Private Attributes
AlgebraicMatrix56	theJacobian

Detailed Description

Class which calculates the Jacobian matrix of the transformation from the Cartesian to the local frame. The Jacobian is calculated during construction and thereafter cached, enabling reuse of the same Jacobian without calculating it again.

Definition at line 15 of file JacobianCartesianToLocal.h.

Constructor & Destructor Documentation

JacobianCartesianToLocal()

JacobianCartesianToLocal::JacobianCartesianToLocal	(	const Surface &	surface,
		const LocalTrajectoryParameters &	localParameters
	)

Constructor from local trajectory parameters and surface defining the local frame. NB!! No default constructor exists!

Definition at line 5 of file JacobianCartesianToLocal.cc.

References LocalTrajectoryParameters::charge(), PV3DBase< T, PVType, FrameType >::mag(), LocalTrajectoryParameters::momentum(), AlCaHLTBitMon_ParallelJobs::p, multPhiCorr_741_25nsDY_cfi::px, multPhiCorr_741_25nsDY_cfi::py, submitPVResolutionJobs::q, dttmaxenums::R, makeMuonMisalignmentScenario::rot, GloballyPositioned< T >::rotation(), theJacobian, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

    : theJacobian() {
  //LocalCoordinates 1 = (q/|p|, dx/dz, dy/dz, x, y)
  //LocalCoordinates 2 = (x, y, z, px, py, pz)
  //Transformation: q/|p| = q/sqrt(px*px + py*py + pz*pz)
  //                dx/dz = px/pz
  //                dy/dz = py/pz
  //                x     = x
  //                y     = y
  LocalVector plocal = localParameters.momentum();
  double px = plocal.x(), py = plocal.y(), pz = plocal.z();
  double p = plocal.mag();
  TrackCharge q = localParameters.charge();
  // for neutrals: qbp is 1/p instead of q/p -
  //   equivalent to charge 1
  if (q == 0)
    q = 1;
  //Jacobian theJacobian( (q/|p|, dx/dz, dy/dz, x, y) = f(x, y, z, px, py, pz) )
  theJacobian(0, 3) = -q * px / (p * p * p);
  theJacobian(0, 4) = -q * py / (p * p * p);
  theJacobian(0, 5) = -q * pz / (p * p * p);
  if (fabs(pz) > 0) {
    theJacobian(1, 3) = 1. / pz;
    theJacobian(1, 5) = -px / (pz * pz);
    theJacobian(2, 4) = 1. / pz;
    theJacobian(2, 5) = -py / (pz * pz);
  }
  theJacobian(3, 0) = 1.;
  theJacobian(4, 1) = 1.;

  /*
  LocalVector l1 = surface.toLocal(GlobalVector(1., 0., 0.));
  LocalVector l2 = surface.toLocal(GlobalVector(0., 1., 0.));
  LocalVector l3 = surface.toLocal(GlobalVector(0., 0., 1.));
  AlgebraicMatrix33 Rsub;
  Rsub(0,0) = l1.x(); Rsub(0,1) = l2.x(); Rsub(0,2) = l3.x();
  Rsub(1,0) = l1.y(); Rsub(1,1) = l2.y(); Rsub(1,2) = l3.y();
  Rsub(2,0) = l1.z(); Rsub(2,1) = l2.z(); Rsub(2,2) = l3.z();
  */

  AlgebraicMatrix33 Rsub;
  // need to be copied anhhow to go from float to double...
  Surface::RotationType const& rot = surface.rotation();
  Rsub(0, 0) = rot.xx();
  Rsub(0, 1) = rot.xy();
  Rsub(0, 2) = rot.xz();
  Rsub(1, 0) = rot.yx();
  Rsub(1, 1) = rot.yy();
  Rsub(1, 2) = rot.yz();
  Rsub(2, 0) = rot.zx();
  Rsub(2, 1) = rot.zy();
  Rsub(2, 2) = rot.zz();

  AlgebraicMatrix66 R;
  R.Place_at(Rsub, 0, 0);
  R.Place_at(Rsub, 3, 3);
  theJacobian = theJacobian * R;
  //dbg::dbg_trace(1,"Ca2L", localParameters.vector(),l1,l2,l3,theJacobian);
}

Member Function Documentation

jacobian()

const AlgebraicMatrix56& JacobianCartesianToLocal::jacobian ( ) const

inline

Access to Jacobian.

Definition at line 26 of file JacobianCartesianToLocal.h.

References theJacobian.

{ return theJacobian; }

Member Data Documentation

theJacobian

AlgebraicMatrix56 JacobianCartesianToLocal::theJacobian

private

Definition at line 29 of file JacobianCartesianToLocal.h.

Referenced by jacobian(), and JacobianCartesianToLocal().