| Geant4 Cross Reference |
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25 //
26 //
27 //
28 // Class Description:
29 //
30 // Represents a free G4ErrorTrajState
31 // It can be represented by the 5 variables
32 // 1/p, lambda, phi, y_perp, z_perp
33 // where lambda and phi are the dip and azimuthal angles related
34 // to the momentum components in the following way:
35 // p_x = p cos(lambda) cos(phi) ! lambda = 90 - theta
36 // p_y = p cos(lambda) sin(phi)
37 // p_z = p sin(lambda)
38 // y_perp and z_perp are the coordinates of the trajectory in a
39 // local orthonormal reference frame with the x_perp axis along the
40 // particle direction, the y_perp being parallel to the x-y plane.
41 //
42 // This class also takes care of propagating the error associated to
43 // the trajectory
44
45 // History:
46 // - Created: P. Arce
47 // --------------------------------------------------------------------
48
49 #ifndef G4ErrorFreeTrajState_hh
50 #define G4ErrorFreeTrajState_hh
51
52 #include "globals.hh"
53
54 #include "G4ErrorMatrix.hh"
55
56 #include "G4ErrorTrajState.hh"
57 #include "G4ErrorFreeTrajParam.hh"
58
59 #include "G4Point3D.hh"
60 #include "G4Vector3D.hh"
61
62 class G4ErrorSurfaceTrajState;
63
64 class G4ErrorFreeTrajState : public G4ErrorTrajState
65 {
66 public: // with description
67 G4ErrorFreeTrajState()
68 : theFirstStep(true)
69 {}
70 G4ErrorFreeTrajState(const G4String& partName, const G4Point3D& pos,
71 const G4Vector3D& mom,
72 const G4ErrorTrajErr& errmat = G4ErrorTrajErr(5, 0));
73 // Constructor by providing particle, position and momentum
74
75 G4ErrorFreeTrajState(const G4ErrorSurfaceTrajState& tpOS);
76 // Constructor by providing G4ErrorSurfaceTrajState
77
78 ~G4ErrorFreeTrajState() {}
79
80 virtual G4int Update(const G4Track* aTrack);
81 // update parameters from G4Track
82
83 virtual G4int PropagateError(const G4Track* aTrack);
84 // propagate the error along the step
85
86 virtual void Dump(std::ostream& out = G4cout) const;
87 // dump TrajState parameters
88
89 friend std::ostream& operator<<(std::ostream&,
90 const G4ErrorFreeTrajState& ts);
91
92 // Set and Get methods
93
94 virtual void SetPosition(const G4Point3D pos)
95 {
96 SetParameters(pos, fMomentum);
97 }
98
99 virtual void SetMomentum(const G4Vector3D& mom)
100 {
101 SetParameters(fPosition, mom);
102 }
103
104 void SetParameters(const G4Point3D& pos, const G4Vector3D& mom)
105 {
106 fPosition = pos;
107 fMomentum = mom;
108 fTrajParam.SetParameters(pos, mom);
109 }
110
111 G4ErrorFreeTrajParam GetParameters() const { return fTrajParam; }
112
113 G4ErrorMatrix GetTransfMat() const { return theTransfMat; }
114
115 private:
116 void Init();
117 // define TrajState type and build charge
118
119 G4int PropagateErrorMSC(const G4Track* aTrack);
120 // add the error associated to multiple scattering
121
122 void CalculateEffectiveZandA(const G4Material* mate, double& effZ,
123 double& effA);
124 // calculate effective Z and A (needed by PropagateErrorMSC)
125
126 G4int PropagateErrorIoni(const G4Track* aTrack);
127 // add the error associated to ionization energy loss
128
129 private:
130 G4ErrorFreeTrajParam fTrajParam;
131
132 G4ErrorMatrix theTransfMat;
133
134 G4bool theFirstStep; // to count if transf mat is updated or initialized
135 };
136
137 #endif
138