BeamSpotAlignmentDerivatives Class Reference

#include <BeamSpotAlignmentDerivatives.h>

Public Member Functions
AlgebraicMatrix	operator() (const TrajectoryStateOnSurface &tsos) const
	Returns 4x2 jacobian matrix. More...

Detailed Description

Calculates derivatives for the alignable beam spot

Date:

2007/03/12 21:28:48

Revision:

1.4

(last update by

Author:

cklae

)

Definition at line 16 of file BeamSpotAlignmentDerivatives.h.

Member Function Documentation

AlgebraicMatrix BeamSpotAlignmentDerivatives::operator()

(

const TrajectoryStateOnSurface &

tsos

)

const

Returns 4x2 jacobian matrix.

Definition at line 17 of file BeamSpotAlignmentDerivatives.cc.

References funct::cos(), PVValHelper::dz, TrajectoryStateOnSurface::globalMomentum(), TrajectoryStateOnSurface::isValid(), TrajectoryStateOnSurface::localPosition(), phi, PV3DBase< T, PVType, FrameType >::phi(), funct::sin(), and PV3DBase< T, PVType, FrameType >::y().

                                                                                                   {
  AlgebraicMatrix aliderivs(4, 2);

  if (!tsos.isValid())
    return aliderivs;

  // lp.x = transverse impact parameter
  // lp.y = longitudinal impact parameter
  LocalPoint lp = tsos.localPosition();
  double phi = tsos.globalMomentum().phi();
  double dz = lp.y();
  double sinphi = sin(phi);
  double cosphi = cos(phi);

  aliderivs[0][0] = sinphi;
  aliderivs[0][1] = 0.0;
  aliderivs[1][0] = -cosphi;
  aliderivs[1][1] = 0.0;
  aliderivs[2][0] = sinphi * dz;
  aliderivs[2][1] = 0.0;
  aliderivs[3][0] = -cosphi * dz;
  aliderivs[3][1] = 0.0;

  return (aliderivs);
}