MTStraightLine.h

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/*
  Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
*/
 
#ifndef MTStraightLineH
#define MTStraightLineH
#include "GeoPrimitives/GeoPrimitives.h"
#include "MuonCalibEventBase/MuonCalibSegment.h"
 
 
namespace MuonCalib {
 
    class MTStraightLine {
    public:
        using MdtHitVec = MuonCalibSegment::MdtHitVec;
        using MdtHitPtr = MuonCalibSegment::MdtHitPtr;
 
        // Constructors //
        MTStraightLine() { init(); }
 
        MTStraightLine(const Amg::Vector3D& r_position, const Amg::Vector3D& r_direction, const Amg::Vector3D& r_position_error,
                       const Amg::Vector3D& r_direction_error) {
            init(r_position, r_direction, r_position_error, r_direction_error);
        }
 
        MTStraightLine(const double  r_a_x1, const double  r_b_x1, const double  r_a_x2, const double  r_b_x2, const double  r_a_x1_err,
                       const double  r_b_x1_err, const double  r_a_x2_err, const double  r_b_x2_err) {
            init(r_a_x1, r_b_x1, r_a_x2, r_b_x2, r_a_x1_err, r_b_x1_err, r_a_x2_err, r_b_x2_err);
        }
 
        // Methods //
        // get-methods //
        Amg::Vector3D positionVector() const;
        Amg::Vector3D directionVector() const;
        Amg::Vector3D positionError() const;
        Amg::Vector3D directionError() const;
        double a_x1() const;
        double a_x1_error() const;
        double b_x1() const;
        double b_x1_error() const;
        double a_x2() const;
        double a_x2_error() const;
        double b_x2() const;
        double b_x2_error() const;
        Amg::Vector3D pointOnLine(const double  lambda) const;
        double signDistFrom(const MTStraightLine& h) const;
        double distFromLine(const Amg::Vector3D& point) const;
 
        void setChi2(double chi2);
        double chi2() const;
 
        void setNumberOfTrackHits(unsigned int n_hits);
        unsigned int numberOfTrackHits() const;
        double chi2PerDegreesOfFreedom() const;
 
        void setUsedHits(const MdtHitVec& hits);
        const MdtHitVec& trackHits() const;
 
    private:
        // internal representation of the straight line //
        Amg::Vector3D m_position{0., 0., 0.};   // position vector of the straight line
        Amg::Vector3D m_direction{0., 0., 0.};  // direction vector of the straight line
 
        // errors on the position and direction vector //
        Amg::Vector3D m_position_error{0., 0., 0.};   // error on the position vector
        Amg::Vector3D m_direction_error{0., 0., 0.};  // error on the direction vector
 
        double m_chi2{-1};
        unsigned int m_numTrkHits{0};
        MdtHitVec m_used_hits;
 
        // initializtion methods //
        void init();  // default initialization method
 
        void init(const Amg::Vector3D& r_position, const Amg::Vector3D& r_direction, const Amg::Vector3D& r_position_error,
                  const Amg::Vector3D& r_direction_error);
        // r_position: position vector of the straight line;
        // r_direction: direction vector of the straight line;
        // r_position_error: error on the position vector;
        // r_direction_error: error on the direction vector
 
        void init(const double  r_a_x1, const double  r_b_x1, const double  r_a_x2, const double  r_b_x2, const double  r_a_x1_err,
                  const double  r_b_x1_err, const double  r_a_x2_err, const double  r_b_x2_err);
        // Coordinates: x1, x2, x3.
        // Parametrization of the straight line: x1 = r_a_x1*x3 + r_b_x1;
        //                                       x2 = r_a_x2*x3 + r_b_x2;
        //                                       x3 arbitrary.
        // r_a_x1_err: error on r_a_x1.
        // r_b_x1_err: error on r_b_x1.
        // r_a_x2_err: error on r_a_x2.
        // r_b_x2_err: error on r_b_x2.
    };
 
}  // namespace MuonCalib
 
#endif