G4ErrorFreeTrajParam.cc

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//
// ------------------------------------------------------------
//      GEANT 4 class implementation file
// ------------------------------------------------------------
//
 
#include "G4ErrorFreeTrajParam.hh"
#include "G4ThreeVector.hh"
#include "G4SystemOfUnits.hh"
 
#include <iomanip>
 
//------------------------------------------------------------------------
G4ErrorFreeTrajParam::G4ErrorFreeTrajParam(const G4Point3D& pos,
                                           const G4Vector3D& mom)
{
  SetParameters(pos, mom);
}
 
//------------------------------------------------------------------------
void G4ErrorFreeTrajParam::SetParameters(const G4Point3D& pos,
                                         const G4Vector3D& mom)
{
  fInvP   = 1. / mom.mag();
  fDir    = mom * fInvP;
  fLambda = 90. * deg - mom.theta();
  fPhi    = mom.phi();
  G4Vector3D vxPerp(0., 0., 0.);
  if(mom.mag() > 0.)
  {
    vxPerp = mom / mom.mag();
  }
  G4Vector3D vyPerp = G4Vector3D(-vxPerp.y(), vxPerp.x(), 0.);
  vyPerp /= vyPerp.mag();
  G4Vector3D vzPerp = vxPerp.cross(vyPerp);
  vzPerp /= vzPerp.mag();
  // check if right handed
  //  fXPerp = pos.proj( mom );
  G4ThreeVector posv(pos);
  if(vyPerp.mag() != 0.)
  {
    // now all 2 scalar memeber variables retain the signs
    //  fYPerp = posv.project( vyPerp ).mag();
    //  fZPerp = posv.project( vzPerp ).mag();
    fYPerp = posv.dot(vyPerp);
    fZPerp = posv.dot(vzPerp);
  }
  else
  {
    fYPerp = 0.;
    fZPerp = 0.;
  }
}
 
//------------------------------------------------------------------------
void G4ErrorFreeTrajParam::Update(const G4Track* aTrack)
{
  SetParameters(aTrack->GetPosition(), aTrack->GetMomentum());
}
 
//------------------------------------------------------------------------
std::ostream& operator<<(std::ostream& out, const G4ErrorFreeTrajParam& tp)
{
  G4int oldprc = out.precision(8);
  out << " InvP= " << tp.fInvP << " Theta= " << tp.fLambda
      << " Phi= " << tp.fPhi << " YPerp= " << tp.fYPerp
      << " ZPerp= " << tp.fZPerp << G4endl;
  out << " momentum direction= " << tp.fDir << G4endl;
  out.precision(oldprc);
 
  return out;
}