Geant4  10.01.p01
G4ClassicalRK4.hh
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27 // $Id: G4ClassicalRK4.hh 66356 2012-12-18 09:02:32Z gcosmo $
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29 //
30 // class G4ClassicalRK4
31 //
32 // Class description:
33 //
34 // Integrate the equations of the motion of a particle in a magnetic field
35 // using the classical 4th Runge-Kutta method.
36 
37 // History:
38 // - Created: J.Apostolakis, V.Grichine - 30.1.97
39 // - Moved into G4MagErrorStepper: W.Wander <wwc@mit.edu> - 12/09/97
40 // -------------------------------------------------------------------
41 
42 #include "G4MagErrorStepper.hh"
43 
45 {
46  public: // with description
47 
48  G4ClassicalRK4(G4EquationOfMotion *EquationMotion, G4int numberOfVariables = 6) ;
49 
50  ~G4ClassicalRK4() ;
51 
52  // A stepper that does not know about errors.
53  // It is used by the MagErrorStepper stepper.
54 
55  void DumbStepper( const G4double yIn[],
56  const G4double dydx[],
57  G4double h,
58  G4double yOut[] ) ;
59  // Given values for the variables y[0,..,n-1] and their derivatives
60  // dydx[0,...,n-1] known at x, use the classical 4th Runge-Kutta
61  // method to advance the solution over an interval h and return the
62  // incremented variables as yout[0,...,n-1], which not be a distinct
63  // array from y. The user supplies the routine RightHandSide(x,y,dydx),
64  // which returns derivatives dydx at x. The source is routine rk4 from
65  // NRC p. 712-713 .
66 
67  public: // without description
68 
69  G4int IntegratorOrder() const { return 4; }
70 
71  private:
72 
73  void StepWithEst( const G4double yIn[],
74  const G4double dydx[],
75  G4double h,
76  G4double yOut[],
77  G4double& alpha2,
78  G4double& beta2,
79  const G4double B1[],
80  G4double B2[] );
81  // No longer used. Obsolete.
82 
85  // Private copy constructor and assignment operator.
86 
87  private:
88 
89  // G4int fNumberOfVariables ; // is set default to 6 in constructor
90 
91  G4double *dydxm, *dydxt, *yt; // scratch space - not state
92 };
G4double * dydxt
G4int IntegratorOrder() const
G4ClassicalRK4 & operator=(const G4ClassicalRK4 &)
int G4int
Definition: G4Types.hh:78
void DumbStepper(const G4double yIn[], const G4double dydx[], G4double h, G4double yOut[])
void StepWithEst(const G4double yIn[], const G4double dydx[], G4double h, G4double yOut[], G4double &alpha2, G4double &beta2, const G4double B1[], G4double B2[])
G4double * dydxm
G4ClassicalRK4(G4EquationOfMotion *EquationMotion, G4int numberOfVariables=6)
double G4double
Definition: G4Types.hh:76