Reconstruction/MdcPatRec/TrkFitter/include/TrkFitter/TrkDifLineTraj.h

Go to the documentation of this file.

//--------------------------------------------------------------------------
// File and Version Information:
//      $Id: TrkDifLineTraj.h,v 1.3 2010/03/25 09:56:53 zhangy Exp $
//
// Description:
//    Trajectory subclass that implements a 3-d line, suitable for use in
//      a track.
//
// Environment:
//      Software developed for the BaBar Detector at the SLAC B-Factory.
//
// Author(s): Steve Schaffner
//------------------------------------------------------------------------
#ifndef TRKDIFLINETRAJ_H
#define TRKDIFLINETRAJ_H
#include "CLHEP/Geometry/Point3D.h"
#include "TrkBase/TrkSimpTraj.h"
#ifndef ENABLE_BACKWARDS_COMPATIBILITY
typedef HepGeom::Point3D<double> HepPoint3D;
#endif
#include "CLHEP/Vector/ThreeVector.h"
 
class TrkVisitor;
class TrkExchangePar;
class TrkDifLineTraj : public TrkSimpTraj {
public:
  //  Define the parameters
  enum { d0Ind = 0, phi0Ind, z0Ind, tanDipInd };
  enum { NLINPRM = 4 };
 
  TrkDifLineTraj( const HepVector&, const HepSymMatrix&, double lowlim = -99999.,
                  double hilim = 99999., const HepPoint3D& refpoint = _theOrigin );
  TrkDifLineTraj( const TrkExchangePar&, double lowlim = -99999., double hilim = 99999.,
                  const HepPoint3D& refpoint = _theOrigin );
  TrkDifLineTraj( const TrkDifLineTraj& ); // copy ctor
  TrkDifLineTraj* clone() const;
  ~TrkDifLineTraj();
  TrkDifLineTraj& operator=( const TrkDifLineTraj& );
 
  virtual HepPoint3D position( double fltLen ) const;
  virtual Hep3Vector direction( double fltLen ) const;
  virtual Hep3Vector delDirect( double ) const;
  virtual void       getInfo( double fltLen, HepPoint3D& pos, Hep3Vector& dir ) const;
  virtual void       getInfo( double fltLen, HepPoint3D&, Hep3Vector& dir,
                              Hep3Vector& delDir ) const;
  virtual void getDFInfo( double fltLen, DifPoint&, DifVector& dir, DifVector& delDir ) const;
  virtual double curvature( double fltLen ) const;
 
  double cosDip() const { return 1. / sqrt( 1. + tanDip() * tanDip() ); }
  double d0() const { return parameters()->parameter()[d0Index()]; }
  double z0() const { return parameters()->parameter()[z0Index()]; }
  double tanDip() const { return parameters()->parameter()[tanDipIndex()]; }
  double phi0() const;
  // yzhang
  int nPar() const { return NLINPRM; }
  // zhangy
  //  How far can you go using given approximation before error > tolerance,
  //    in direction pathDir?
  virtual double distTo1stError( double flt, double tol, int pathDir ) const;
  virtual double distTo2ndError( double flt, double tol, int pathDir ) const;
 
  //  Real versions of the base class derivative functions
  HepMatrix derivDeflect( double fltlen, deflectDirection ) const;
  HepMatrix derivDisplace( double fltlen, deflectDirection ) const;
  HepMatrix derivPFract( double fltlen ) const;
  //  PointTraj functions
  TranslateParams paramFunction() const { return TrkDifLineTraj::paramFunc; }
  // Invert the parameter.  Returns true in flags if the inversion
  // requires a change of sign in the covariance matrix.
  void invertParams( TrkParams* params, std::vector<bool>& flags ) const;
 
  //--------------------------------------------------
  // Visitor access
  //--------------------------------------------------
 
  virtual void visitAccept( TrkVisitor* vis ) const;
 
private:
  //  Private functions (data members are part of the base class)
  double x( const double& ) const;
  double y( const double& ) const;
  double z( const double& ) const;
  int    d0Index() const { return d0Ind; }
  int    phi0Index() const { return phi0Ind; }
  int    z0Index() const { return z0Ind; }
  int    tanDipIndex() const { return tanDipInd; }
  int    nLinPrm() const { return NLINPRM; }
 
  // the real point translation function
  static void paramFunc( const HepPoint3D& oldpoint, const HepPoint3D& newpoint,
                         const HepVector& oldpar, const HepSymMatrix& oldcov,
                         HepVector& newpar, HepSymMatrix& newcov, double fltlen );
};
 
// Inline functions:
 
#endif