Geant4  10.03.p03
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
G4ClassicalRK4.hh
Go to the documentation of this file.
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 // $Id: G4ClassicalRK4.hh 101384 2016-11-16 11:03:44Z gcosmo $
28 //
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 // - Fix: D.Sorokin add header guard
41 // -------------------------------------------------------------------
42 
43 #ifndef G4ClassicalRK4_HH
44 #define G4ClassicalRK4_HH
45 
46 #include "G4MagErrorStepper.hh"
47 
49 {
50  public: // with description
51 
52  G4ClassicalRK4(G4EquationOfMotion *EquationMotion, G4int numberOfVariables = 6) ;
53 
54  ~G4ClassicalRK4() ;
55 
56  // A stepper that does not know about errors.
57  // It is used by the MagErrorStepper stepper.
58 
59  void DumbStepper( const G4double yIn[],
60  const G4double dydx[],
61  G4double h,
62  G4double yOut[] ) ;
63  // Given values for the variables y[0,..,n-1] and their derivatives
64  // dydx[0,...,n-1] known at x, use the classical 4th Runge-Kutta
65  // method to advance the solution over an interval h and return the
66  // incremented variables as yout[0,...,n-1], which not be a distinct
67  // array from y. The user supplies the routine RightHandSide(x,y,dydx),
68  // which returns derivatives dydx at x. The source is routine rk4 from
69  // NRC p. 712-713 .
70 
71  public: // without description
72 
73  G4int IntegratorOrder() const { return 4; }
74 
75  private:
76 
77  void StepWithEst( const G4double yIn[],
78  const G4double dydx[],
79  G4double h,
80  G4double yOut[],
81  G4double& alpha2,
82  G4double& beta2,
83  const G4double B1[],
84  G4double B2[] );
85  // No longer used. Obsolete.
86 
88  G4ClassicalRK4& operator=(const G4ClassicalRK4&);
89  // Private copy constructor and assignment operator.
90 
91  private:
92 
93  // G4int fNumberOfVariables ; // is set default to 6 in constructor
94 
95  G4double *dydxm, *dydxt, *yt; // scratch space - not state
96 };
97 
98 #endif
G4int IntegratorOrder() const
int G4int
Definition: G4Types.hh:78
void DumbStepper(const G4double yIn[], const G4double dydx[], G4double h, G4double yOut[])
G4ClassicalRK4(G4EquationOfMotion *EquationMotion, G4int numberOfVariables=6)
double G4double
Definition: G4Types.hh:76