include/Geant4/G4EquationOfMotion.hh

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0025 //
0026 // G4EquationOfMotion
0027 //
0028 // Class description:
0029 //
0030 // Abstract Base Class for the right hand size of the equation of
0031 // motion of a particle in a field.
0032
0033 // Created: J.Apostolakis, 1998
0034 // -------------------------------------------------------------------
0035 #ifndef G4EQUATIONOFMOTION_HH
0036 #define G4EQUATIONOFMOTION_HH
0037
0038 #include "G4Types.hh"
0039 #include "G4Field.hh"   // required in inline method implementations
0040
0041 #include "G4ChargeState.hh"
0042
0043 class G4EquationOfMotion
0044 {
0045   public:  // with description
0046
0047      G4EquationOfMotion( G4Field* Field );
0048      virtual ~G4EquationOfMotion();
0049        // Constructor and virtual destructor. No operations.
0050
0051      virtual void EvaluateRhsGivenB( const G4double y[],
0052                                      const G4double B[3],
0053                                      G4double dydx[] ) const = 0;
0054        // Given the value of the  field "B", this function
0055        // calculates the value of the derivative dydx.
0056        // --------------------------------------------------------
0057        // This is the _only_ function a subclass must define.
0058        // The other two functions use Rhs_givenB.
0059
0060      virtual void SetChargeMomentumMass(G4ChargeState particleCharge,
0061                                         G4double MomentumXc,
0062                                         G4double MassXc2) = 0;
0063        // Set the charge, momentum and mass of the current particle
0064        // --> used to set the equation's coefficients ...
0065
0066      inline void RightHandSide( const G4double y[],
0067                                       G4double dydx[] ) const;
0068        // This calculates the value of the derivative dydx at y.
0069        // It is the usual enquiry function.
0070        // ---------------------------
0071        // (It is not virtual, but calls the virtual function above.)
0072
0073      inline void EvaluateRhsReturnB( const G4double y[],
0074                                            G4double dydx[],
0075                                            G4double Field[] ) const;
0076        // Same as RHS above, but also returns the value of B.
0077        // Should be made the new default ? after putting dydx & B in a class.
0078
0079      inline void GetFieldValue( const G4double Point[4],
0080                                       G4double Field[] ) const;
0081        // Obtain only the field - the stepper assumes it is pure Magnetic.
0082        // Not protected, because G4RKG3_Stepper uses it directly.
0083
0084      inline const G4Field* GetFieldObj() const;
0085      inline G4Field* GetFieldObj();
0086      inline void SetFieldObj(G4Field* pField);
0087
0088   private:
0089
0090      G4Field* itsField = nullptr;
0091 };
0092
0093 #include "G4EquationOfMotion.icc"
0094
0095 #endif