RecHitPropagator Class Reference

#include <RecHitPropagator.h>

Public Member Functions
TrajectoryStateOnSurface	propagate (const TrackingRecHit &hit, const Plane &plane, const TrajectoryStateOnSurface &ts) const

Detailed Description

Definition at line 10 of file RecHitPropagator.h.

Member Function Documentation

propagate()

TrajectoryStateOnSurface RecHitPropagator::propagate	(	const TrackingRecHit &	hit,
		const Plane &	plane,
		const TrajectoryStateOnSurface &	ts
	)		const

Definition at line 5 of file RecHitPropagator.cc.

References anyDirection, TrajectoryStateOnSurface::charge(), geometryDiff::epsilon, TrajectoryStateOnSurface::globalParameters(), visualization-live-secondInstance_cfg::m, GlobalTrajectoryParameters::magneticField(), AnalyticalPropagator::propagate(), TrajectoryStateOnSurface::surface(), LocalError::xx(), LocalError::xy(), and LocalError::yy().

Referenced by TkGluedMeasurementDet::checkHitProjection().

                                                                                               {
  const MagneticField& field = ts.globalParameters().magneticField();
  AnalyticalPropagator prop(&field, anyDirection);
  TrajectoryStateOnSurface tsNoErr = TrajectoryStateOnSurface(ts.globalParameters(), ts.surface());
  TrajectoryStateOnSurface hitts = prop.propagate(tsNoErr, hit.det()->specificSurface());

  // LocalVector ldir = hit.det()->specificSurface().toLocal(ts.globalMomentum());
  LocalVector ldir = hitts.localMomentum();
  LocalTrajectoryParameters ltp(hit.localPosition(), ldir, ts.charge());
  AlgebraicSymMatrix55 m;
  LocalError lhe = hit.localPositionError();
  m[3][3] = lhe.xx();
  m[3][4] = lhe.xy();
  m[4][4] = lhe.yy();

  const double epsilon = 1.e-8;  // very small errors on momentum and angle
  m[0][0] = epsilon;
  m[1][1] = epsilon;
  m[2][2] = epsilon;
  LocalTrajectoryError lte(m);

  TrajectoryStateOnSurface startingState(ltp, lte, hit.det()->specificSurface(), &field);

  return prop.propagate(startingState, plane);
}