RecHitPropagator.h File Reference

#include "TrackingTools/TrajectoryState/interface/TrajectoryStateOnSurface.h"
#include "Geometry/CommonDetUnit/interface/GeomDet.h"

Go to the source code of this file.

Classes
class	RecHitPropagator

Functions
TrajectoryStateOnSurface	fastProp (const TrajectoryStateOnSurface &ts, const Plane &oPlane, const Plane &tPlane)

Function Documentation

fastProp()

TrajectoryStateOnSurface fastProp ( const TrajectoryStateOnSurface &  ts, const Plane &  oPlane, const Plane &  tPlane  )

inline

Definition at line 20 of file RecHitPropagator.h.

References TrajectoryStateOnSurface::charge(), TrajectoryStateOnSurface::curvilinearError(), dumpMFGeometry_cfg::delta, TrajectoryStateOnSurface::globalMomentum(), TrajectoryStateOnSurface::globalParameters(), TrajectoryStateOnSurface::globalPosition(), runTauDisplay::gp, TrajectoryStateOnSurface::hasError(), Plane::localZ(), GlobalTrajectoryParameters::magneticField(), GloballyPositioned< T >::position(), Surface::toGlobal(), GloballyPositioned< T >::toLocal(), and PV3DBase< T, PVType, FrameType >::z().

                                                                                                                       {
  GlobalVector gdir = ts.globalMomentum();
  LocalVector ldir = tPlane.toLocal(gdir);  // fast prop!

  // if ldir.z() == 0, return an invalid TrajectoryStateOnSurface
  if (ldir.z() == 0) {
    return TrajectoryStateOnSurface();
  }

  double delta = tPlane.localZ(oPlane.position());
  LocalPoint lPos = tPlane.toLocal(ts.globalPosition());
  LocalPoint projectedPos = lPos - ldir * delta / ldir.z();
  // we can also patch it up as only the position-errors are used...
  GlobalTrajectoryParameters gp(
      tPlane.toGlobal(projectedPos), gdir, ts.charge(), &ts.globalParameters().magneticField());
  if (ts.hasError())
    return TrajectoryStateOnSurface(gp, ts.curvilinearError(), tPlane);
  else
    return TrajectoryStateOnSurface(gp, tPlane);
}