Reconstruction/MdcPatRec/TrkFitter/include/TrkFitter/TrkCircleTraj.h

Go to the documentation of this file.

//--------------------------------------------------------------------------
// File and Version Information:
//      $Id: TrkCircleTraj.h,v 1.2 2006/03/28 01:03:35 zhangy Exp $
//
// Description:
//    Trajectory subclass that implements a circle in the x-y plane, suitable
//    for use in a track.
//
// Environment:
//      Software developed for the BaBar Detector at the SLAC B-Factory.
//
// Author(s): Steve Schaffner
//------------------------------------------------------------------------
#ifndef TRKCIRCLETRAJ_H
#define TRKCIRCLETRAJ_H
#include "CLHEP/Geometry/Point3D.h"
#include "TrkBase/TrkSimpTraj.h"
#ifndef ENABLE_BACKWARDS_COMPATIBILITY
typedef HepGeom::Point3D<double> HepPoint3D;
#endif
#include "CLHEP/Matrix/SymMatrix.h"
#include "CLHEP/Vector/ThreeVector.h"
 
class TrkVisitor;
class TrkExchangePar;
 
class TrkCircleTraj : public TrkSimpTraj {
 
public:
  TrkCircleTraj( const HepVector&, const HepSymMatrix&, double lowlim = -99999.,
                 double hilim = 99999., const HepPoint3D& refpoint = _theOrigin );
  TrkCircleTraj( const TrkExchangePar&, double lowlim = -99999., double hilim = 99999.,
                 const HepPoint3D& refpoint = _theOrigin );
  TrkCircleTraj( const TrkCircleTraj& ); // copy ctor
  TrkCircleTraj* clone() const;
  ~TrkCircleTraj();
  TrkCircleTraj& operator=( const TrkCircleTraj& );
 
  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 void getDFInfo2( double fltLen, DifPoint& pos, DifVector& dir ) const;
  virtual double curvature( double fltLen ) const;
 
  // 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 TrkCircleTraj::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;
  // yzhang
  int nPar() const { return NCIRPAR; }
  // zhangy
  //--------------------------------------------------
  //  Visitor access
  //--------------------------------------------------
 
  virtual void visitAccept( TrkVisitor* vis ) const;
 
  //  Define the parameters
private:
  enum { d0Ind = 0, phi0Ind, omegaInd };
  enum { NCIRPAR = 3 };
 
public:
  static int d0Index() { return d0Ind; }
  static int phi0Index() { return phi0Ind; }
  static int omegaIndex() { return omegaInd; }
  static int nCirPrm() { return NCIRPAR; }
 
  // circle-specific accessors
  double d0() const { return parameters()->parameter()[d0Index()]; }
  double phi0() const;
  double omega() const { return parameters()->parameter()[omegaIndex()]; }
 
private:
  //  Private functions (data members are part of the base class)
 
  double        x( const double& ) const;
  double        y( const double& ) const;
  inline double arc( const double& f ) const { return f * omega(); }
  double        angle( const double& f ) const;
  // 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 );
};
#endif