/data/doxygen/doxygen-1.7.3/gen/CMSSW_4_2_8/src/TrackingTools/TrajectoryState/src/TrajectoryStateTransform.cc

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#include "TrackingTools/TrajectoryState/interface/TrajectoryStateTransform.h"
#include "DataFormats/TrackReco/interface/Track.h" 
#include "TrackingTools/TrajectoryState/interface/TrajectoryStateOnSurface.h"
#include "TrackingTools/TrajectoryState/interface/FreeTrajectoryState.h" 
#include "DataFormats/GeometrySurface/interface/Surface.h" 
#include "TrackingTools/TrajectoryParametrization/interface/GlobalTrajectoryParameters.h"
#include "Geometry/CommonDetUnit/interface/TrackingGeometry.h"
#include "Geometry/CommonDetUnit/interface/GeomDet.h"

using namespace SurfaceSideDefinition;

PTrajectoryStateOnDet* 
TrajectoryStateTransform::persistentState( const TrajectoryStateOnSurface& ts,
                                           unsigned int detid) const
{
  AlgebraicSymMatrix55 m = ts.localError().matrix();
  
  int dim = 5; 

  float localErrors[15];
  int k = 0;
  for (int i=0; i<dim; i++) {
    for (int j=0; j<=i; j++) {
      localErrors[k++] = m(i,j);
    }
  }
  int surfaceSide = static_cast<int>(ts.surfaceSide());

  return new PTrajectoryStateOnDet( ts.localParameters(),
                                    localErrors, detid,
                                    surfaceSide);
}

TrajectoryStateOnSurface 
TrajectoryStateTransform::transientState( const PTrajectoryStateOnDet& ts,
                                          const Surface* surface,
                                          const MagneticField* field) const
{
  int dim = 5;
  AlgebraicSymMatrix55 m;
  const std::vector<float> &errs = ts.errorMatrix();  
  int k = 0;
  for (int i=0; i<dim; i++) {
    for (int j=0; j<=i; j++) {
      m(i,j) = errs[k++];       // NOTE: here we do a cast float => double.     
    }
  }
  

  return TrajectoryStateOnSurface( ts.parameters(),
                                   LocalTrajectoryError(m), 
                                   *surface, field,
                                   static_cast<SurfaceSide>(ts.surfaceSide()));

}

FreeTrajectoryState TrajectoryStateTransform::initialFreeState( const reco::Track& tk,
                                                              const MagneticField* field) const
{
  Basic3DVector<float> pos( tk.vertex());
  GlobalPoint gpos( pos);
  Basic3DVector<float> mom( tk.momentum());
  GlobalVector gmom( mom);
  GlobalTrajectoryParameters par( gpos, gmom, tk.charge(), field);
  CurvilinearTrajectoryError err( tk.covariance());
  return FreeTrajectoryState( par, err);
}

FreeTrajectoryState TrajectoryStateTransform::innerFreeState( const reco::Track& tk,
                                                              const MagneticField* field) const
{
  Basic3DVector<float> pos( tk.innerPosition());
  GlobalPoint gpos( pos);
  Basic3DVector<float> mom( tk.innerMomentum());
  GlobalVector gmom( mom);
  GlobalTrajectoryParameters par( gpos, gmom, tk.charge(), field);
  CurvilinearTrajectoryError err( tk.extra()->innerStateCovariance());
  return FreeTrajectoryState( par, err);
}


FreeTrajectoryState TrajectoryStateTransform::outerFreeState( const reco::Track& tk,
                                                              const MagneticField* field) const
{
  Basic3DVector<float> pos( tk.outerPosition());
  GlobalPoint gpos( pos);
  Basic3DVector<float> mom( tk.outerMomentum());
  GlobalVector gmom( mom);
  GlobalTrajectoryParameters par( gpos, gmom, tk.charge(), field);
  CurvilinearTrajectoryError err( tk.extra()->outerStateCovariance());
  return FreeTrajectoryState( par, err);
}


TrajectoryStateOnSurface TrajectoryStateTransform::innerStateOnSurface( const reco::Track& tk, 
                                                                        const TrackingGeometry& geom,
                                                                        const MagneticField* field) const
{
  const Surface& surface = geom.idToDet( DetId( tk.extra()->innerDetId()))->surface();
  return TrajectoryStateOnSurface( innerFreeState( tk, field), surface);
}

TrajectoryStateOnSurface TrajectoryStateTransform::outerStateOnSurface( const reco::Track& tk, 
                                                                        const TrackingGeometry& geom,
                                                                        const MagneticField* field) const
{
  const Surface& surface = geom.idToDet( DetId( tk.extra()->outerDetId()))->surface();
  return TrajectoryStateOnSurface( outerFreeState( tk, field), surface);
}