JacobianLocalToCartesian Class Reference

#include <JacobianLocalToCartesian.h>

Public Member Functions
const AlgebraicMatrix65 &	jacobian () const
	JacobianLocalToCartesian (const Surface &surface, const LocalTrajectoryParameters &localParameters)

Private Attributes
AlgebraicMatrix65	theJacobian

Detailed Description

Class which calculates the Jacobian matrix of the transformation from the local to the Caresian 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 JacobianLocalToCartesian.h.

Constructor & Destructor Documentation

JacobianLocalToCartesian()

JacobianLocalToCartesian::JacobianLocalToCartesian	(	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 JacobianLocalToCartesian.cc.

    : theJacobian() {
  //LocalCoordinates 1 = (x, y, z, px, py, pz)
  //LocalCoordinates 2 = (q/|p|, dx/dz, dy/dz, x, y)
  //Transformation: x  = x
  //                y  = y
  //          px = (q/(q/|p|)) * (dx/dz) *  sqrt(1./(1.+(dx/dz)^2+(dy/dz)^2))
  //          py = (q/(q/|p|)) * (dy/dz) * sqrt(1./(1.+(dx/dz)^2+(dy/dz)^2))
  //          pz = (q/(q/|p|)) * sqrt(1./(1.+(dx/dz)^2+(dy/dz)^2))
  //Jacobian J((x, y, px, py, pz)  = f(q/|p|, dx/dz, dy/dz, x, y))
 
  // AlgebraicVector5 localTrackParams = localParameters.mixedFormatVector();
  double qbp = localParameters.qbp();
  double dxdz = localParameters.dxdz();
  double dydz = localParameters.dydz();
  TrackCharge iq = localParameters.charge();
  // for neutrals: qbp is 1/p instead of q/p -
  //   equivalent to charge 1
  if (iq == 0)
    iq = 1;
  double pzSign = localParameters.pzSign();
  double q = iq * pzSign;
  double sqr = sqrt(dxdz * dxdz + dydz * dydz + 1);
  double den = -q / (sqr * sqr * sqr * qbp);
 
  // no difference between local and data member
  AlgebraicMatrix65& lJacobian = theJacobian;
  lJacobian(0, 3) = 1.;
  lJacobian(1, 4) = 1.;
  lJacobian(3, 0) = (dxdz * (-q / (sqr * qbp * qbp)));
  lJacobian(3, 1) = (q / (sqr * qbp) + (den * dxdz * dxdz));
  lJacobian(3, 2) = ((den * dxdz * dydz));
  lJacobian(4, 0) = (dydz * (-q / (sqr * qbp * qbp)));
  lJacobian(4, 1) = ((den * dxdz * dydz));
  lJacobian(4, 2) = (q / (sqr * qbp) + (den * dydz * dydz));
  lJacobian(5, 0) = (-q / (sqr * qbp * qbp));
  lJacobian(5, 1) = ((den * dxdz));
  lJacobian(5, 2) = ((den * dydz));
 
  /*
  GlobalVector g1 = surface.toGlobal(LocalVector(1., 0., 0.));
  GlobalVector g2 = surface.toGlobal(LocalVector(0., 1., 0.));
  GlobalVector g3 = surface.toGlobal(LocalVector(0., 0., 1.));
  */
  AlgebraicMatrix33 Rsub;
  /*
  Rsub(0,0) = g1.x(); Rsub(0,1) = g2.x(); Rsub(0,2) = g3.x();
  Rsub(1,0) = g1.y(); Rsub(1,1) = g2.y(); Rsub(1,2) = g3.y();
  Rsub(2,0) = g1.z(); Rsub(2,1) = g2.z(); Rsub(2,2) = g3.z();
  */
  // 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.yx();
  Rsub(0, 2) = rot.zx();
  Rsub(1, 0) = rot.xy();
  Rsub(1, 1) = rot.yy();
  Rsub(1, 2) = rot.zy();
  Rsub(2, 0) = rot.xz();
  Rsub(2, 1) = rot.yz();
  Rsub(2, 2) = rot.zz();
 
  AlgebraicMatrix66 R;
  R.Place_at(Rsub, 0, 0);
  R.Place_at(Rsub, 3, 3);
  theJacobian = R * lJacobian;
  //dbg::dbg_trace(1,"Loc2Ca", localParameters.vector(),g1,g2,g3,theJacobian);
}

References LocalTrajectoryParameters::charge(), BeamSpotPI::dxdz, LocalTrajectoryParameters::dxdz(), BeamSpotPI::dydz, LocalTrajectoryParameters::dydz(), LocalTrajectoryParameters::pzSign(), submitPVResolutionJobs::q, LocalTrajectoryParameters::qbp(), dttmaxenums::R, makeMuonMisalignmentScenario::rot, GloballyPositioned< T >::rotation(), sqr(), mathSSE::sqrt(), and theJacobian.

Member Function Documentation

jacobian()

const AlgebraicMatrix65& JacobianLocalToCartesian::jacobian ( ) const

inline

Access to Jacobian.

Definition at line 26 of file JacobianLocalToCartesian.h.

{ return theJacobian; }

References theJacobian.

Member Data Documentation

theJacobian

AlgebraicMatrix65 JacobianLocalToCartesian::theJacobian

private

Definition at line 29 of file JacobianLocalToCartesian.h.

Referenced by jacobian(), and JacobianLocalToCartesian().