CbmLitRK4TrackExtrapolator.h

Go to the documentation of this file.

/* Copyright (C) 2007-2019 GSI/JINR-LIT, Darmstadt/Dubna
   SPDX-License-Identifier: GPL-3.0-only
   Authors: Andrey Lebedev [committer] */
 
#ifndef CBMLITRK4TRACKEXTRAPOLATOR_H_
#define CBMLITRK4TRACKEXTRAPOLATOR_H_
 
#include "data/CbmLitTrackParam.h"
#include "interface/CbmLitTrackExtrapolator.h"
 
#include <memory>
#include <vector>
 
class CbmLitField;
 
class CbmLitRK4TrackExtrapolator : public CbmLitTrackExtrapolator {
 public:
  /* Constructor with field
    *@param field Magnetic field.
    */
  CbmLitRK4TrackExtrapolator(std::shared_ptr<CbmLitField> field);
  //CbmLitField* field);
 
  /* Destructor */
  virtual ~CbmLitRK4TrackExtrapolator();
 
  /* Inherited from CbmLitTrackExtrapolation */
  virtual LitStatus Extrapolate(const CbmLitTrackParam* parIn, CbmLitTrackParam* parOut, litfloat zOut,
                                std::vector<litfloat>* F);
 
  /* Inherited from CbmLitTrackExtrapolation */
  virtual LitStatus Extrapolate(CbmLitTrackParam* par, litfloat zOut, std::vector<litfloat>* F);
 
 protected:
  /* Calculates output track parameters and derivatives with the 4th order Runge-Kutta method.
    * @param xIn Input track parameters vector (x, y, tx, ty, q/p).
    * @param zIn Input Z position [cm].
    * @param xOut Output track parameters vector (x, y, tx, ty, q/p)
    * @param zOut Input Z position to extrapolate to [cm].
    * @param derivs Vector with integrated derivatives.
    */
 
  void RK4Order(const std::vector<litfloat>& xIn, litfloat zIn, std::vector<litfloat>& xOut, litfloat zOut,
                std::vector<litfloat>& derivs) const;
 
  /* TODO: add comment */
  litfloat CalcOut(litfloat in, const litfloat k[4]) const;
 
  /* Transport the covariance matrix, using formula cOut = F*cIn*Ft.
    * @param cIn Input covariance matrix.
    * @param F Input transport matrix.
    * @param cOut Output covariance matrix.
    */
  void TransportC(const std::vector<litfloat>& cIn, const std::vector<litfloat>& F, std::vector<litfloat>& cOut) const;
 
 private:
  std::shared_ptr<CbmLitField> fField;
  //CbmLitField* fField; // magnetic field
};
 
#endif  //CBMLITRK4TRACKEXTRAPOLATOR_H_