Geant4  10.02.p02
G4SimpleHeum.cc
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27 // $Id: G4SimpleHeum.cc 66356 2012-12-18 09:02:32Z gcosmo $
28 //
29 // Simple Heum:
30 // x_1 = x_0 + h *
31 // 1/4 * dx(t0,x0) +
32 // 3/4 * dx(t0+2/3*h, x0+2/3*h*(dx(t0+h/3,x0+h/3*dx(t0,x0))))
33 //
34 // Third order solver.
35 //
36 // W.Wander <wwc@mit.edu> 12/09/97
37 // -------------------------------------------------------------------
38 
39 #include "G4SimpleHeum.hh"
40 #include "G4ThreeVector.hh"
41 
43 //
44 // Constructor
45 
47  G4MagErrorStepper(EqRhs, num_variables),
48  fNumberOfVariables(num_variables)
49 {
54 }
55 
56 
58 //
59 // Destructor
60 
62 {
63  delete[] dydxTemp;
64  delete[] dydxTemp2;
65  delete[] yTemp;
66  delete[] yTemp2;
67 }
68 
69 
71 //
72 //
73 
74 void
76  const G4double dydx[],
77  G4double h,
78  G4double yOut[])
79 {
80  G4int i;
81  for( i = 0; i < fNumberOfVariables; i++ )
82  {
83  yTemp[i] = yIn[i] + (1.0/3.0) * h * dydx[i] ;
84  }
85 
87 
88  for( i = 0; i < fNumberOfVariables; i++ )
89  {
90  yTemp2[i] = yIn[i] + (2.0/3.0) * h * dydxTemp[i] ;
91  }
92 
94 
95  for( i = 0; i < fNumberOfVariables; i++ )
96  {
97  yOut[i] = yIn[i] + h * (0.25 * dydx[i] + 0.75 * dydxTemp2[i]);
98  }
99 
100  if ( fNumberOfVariables == 12 ) { NormalisePolarizationVector( yOut ); }
101 }
void DumbStepper(const G4double y[], const G4double dydx[], G4double h, G4double yout[])
Definition: G4SimpleHeum.cc:75
int G4int
Definition: G4Types.hh:78
G4SimpleHeum(G4EquationOfMotion *EqRhs, G4int num_variables=6)
Definition: G4SimpleHeum.cc:46
G4int fNumberOfVariables
Definition: G4SimpleHeum.hh:70
G4double * dydxTemp
Definition: G4SimpleHeum.hh:72
G4double * yTemp
Definition: G4SimpleHeum.hh:74
void RightHandSide(const double y[], double dydx[])
void NormalisePolarizationVector(G4double vec[12])
G4double * yTemp2
Definition: G4SimpleHeum.hh:75
double G4double
Definition: G4Types.hh:76
G4double * dydxTemp2
Definition: G4SimpleHeum.hh:73