VolumeMaterialEffectsUpdator Class Reference

#include <VolumeMaterialEffectsUpdator.h>

Public Types
typedef VolumeMaterialEffectsEstimate	Estimate
typedef std::vector< const VolumeMaterialEffectsEstimate * >	EstimateContainer

Public Member Functions
TrajectoryStateOnSurface	updateState (const TrajectoryStateOnSurface &TSoS, const PropagationDirection propDir, const Estimate &estimate) const
TrajectoryStateOnSurface	updateState (const TrajectoryStateOnSurface &TSoS, const PropagationDirection propDir, const EstimateContainer &estimates) const
	VolumeMaterialEffectsUpdator ()

Detailed Description

Computes an updated TrajectoryStateOnSurface after applying estimated material effects.

Definition at line 18 of file VolumeMaterialEffectsUpdator.h.

Member Typedef Documentation

typedef VolumeMaterialEffectsEstimate VolumeMaterialEffectsUpdator::Estimate

Definition at line 21 of file VolumeMaterialEffectsUpdator.h.

typedef std::vector<const VolumeMaterialEffectsEstimate*> VolumeMaterialEffectsUpdator::EstimateContainer

Definition at line 22 of file VolumeMaterialEffectsUpdator.h.

Constructor & Destructor Documentation

VolumeMaterialEffectsUpdator::VolumeMaterialEffectsUpdator ( )

inline

Definition at line 25 of file VolumeMaterialEffectsUpdator.h.

{}

Member Function Documentation

TrajectoryStateOnSurface VolumeMaterialEffectsUpdator::updateState	(	const TrajectoryStateOnSurface &	TSoS,
		const PropagationDirection	propDir,
		const Estimate &	estimate
	)		const

Updates TrajectoryStateOnSurface with material effects (momentum and covariance matrix are potentially affected.

Definition at line 12 of file VolumeMaterialEffectsUpdator.cc.

{
  return updateState(tsos,propDir,EstimateContainer(1,&estimate));
}

TrajectoryStateOnSurface VolumeMaterialEffectsUpdator::updateState	(	const TrajectoryStateOnSurface &	TSoS,
		const PropagationDirection	propDir,
		const EstimateContainer &	estimates
	)		const

Updates TrajectoryStateOnSurface with several material effects (momentum and covariance matrix are potentially affected.

Definition at line 20 of file VolumeMaterialEffectsUpdator.cc.

References alongMomentum, anyDirection, TrajectoryStateOnSurface::charge(), TrajectoryStateOnSurface::globalMomentum(), TrajectoryStateOnSurface::globalParameters(), TrajectoryStateOnSurface::globalPosition(), TrajectoryStateOnSurface::hasError(), i, TrajectoryStateOnSurface::localError(), TrajectoryStateOnSurface::localParameters(), TrajectoryStateOnSurface::magneticField(), GlobalTrajectoryParameters::magneticField(), LocalTrajectoryError::matrix(), TrajectoryStateOnSurface::surface(), TrajectoryStateOnSurface::surfaceSide(), and LocalTrajectoryParameters::updateP().

{
  // Sanity check on propagation direction
  if ( propDir==anyDirection )  return TrajectoryStateOnSurface();
  //
  // Update momentum. In case of failure: return invalid state
  //
  double dpSum(0.);
  for ( EstimateContainer::const_iterator i=estimates.begin();
    i!=estimates.end(); ++i ) {
    double dp = (**i).deltaP();
    if ( propDir==alongMomentum )  dpSum += dp;
    else  dpSum -= dp;
  }
  LocalTrajectoryParameters lp = tsos.localParameters();
  if ( !lp.updateP(dpSum) )  return TrajectoryStateOnSurface();
  //
  // Update covariance matrix?
  //
  if ( tsos.hasError() ) {
//     AlgebraicSymMatrix55 eloc(tsos.localError().matrix());
    AlgebraicSymMatrix55 matCov;
    for ( EstimateContainer::const_iterator i=estimates.begin();
      i!=estimates.end(); ++i ) {
      matCov += (**i).deltaLocalError();
    }
    //
    // transform to local system of trackfor the time being: brute force
    // could / should try to construct the matrix in curvilinear
    //
    // Plane consistent with material effects estimate (perp. to track at ref. pos.)
    ReferenceCountingPointer<BoundPlane> 
      perpPlane(PerpendicularBoundPlaneBuilder()(tsos.globalPosition(),
                         tsos.globalMomentum()));
    // Parameters need to construct Jacobian (ref. point and ref. direction)
    LocalTrajectoryParameters perpPars(LocalPoint(0.,0.,0.),
                       LocalVector(0.,0.,1.),
                       tsos.charge());
    // Jacobian to go from perpendicular plane to curvilinear
    JacobianLocalToCurvilinear jacLocToCurv(*perpPlane,perpPars,*tsos.magneticField());
    // Jacobian to go from curvilinear to local frame of the reference tsos
    JacobianCurvilinearToLocal jacCurvToLoc(tsos.surface(),tsos.localParameters(),
                        *tsos.magneticField());
    // Combined Jacobian
    AlgebraicMatrix55 jac(jacLocToCurv.jacobian()*jacCurvToLoc.jacobian());
    // Add transformed material effects error matrix to the one from the TSOS
    AlgebraicSymMatrix55 eloc(tsos.localError().matrix());
    eloc += ROOT::Math::Similarity(jac,matCov);
    return TrajectoryStateOnSurface(lp,LocalTrajectoryError(eloc),tsos.surface(),
                    &(tsos.globalParameters().magneticField()),
                    tsos.surfaceSide());
  }
  else {
    return TrajectoryStateOnSurface(lp,tsos.surface(),
                    &(tsos.globalParameters().magneticField()),
                    tsos.surfaceSide());
  }
}