Geant4_10
G4HelixHeum.cc
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27 // $Id: G4HelixHeum.cc 66356 2012-12-18 09:02:32Z gcosmo $
28 //
29 //
30 // Simple Heum:
31 // x_1 = x_0 + h *
32 // 1/4 * dx(t0,x0) +
33 // 3/4 * dx(t0+2/3*h, x0+2/3*h*(dx(t0+h/3,x0+h/3*dx(t0,x0))))
34 //
35 // Third order solver.
36 //
37 // W.Wander <wwc@mit.edu> 12/09/97
38 // -------------------------------------------------------------------
39 
40 #include "G4HelixHeum.hh"
41 #include "G4ThreeVector.hh"
42 
43 void
45  G4ThreeVector Bfld,
46  G4double h,
47  G4double yOut[])
48 {
49  const G4int nvar = 6 ;
50 
51  G4ThreeVector Bfield_Temp, Bfield_Temp2;
52  G4double yTemp[6], yAdd1[6], yAdd2[6] , yTemp2[6];
53 
54  G4int i;
55 
56  AdvanceHelix( yIn, Bfld, h, yAdd1 );
57 
58  AdvanceHelix( yIn, Bfld, h/3.0, yTemp );
59  MagFieldEvaluate(yTemp,Bfield_Temp);
60 
61  AdvanceHelix( yIn, Bfield_Temp, (2.0 / 3.0) * h, yTemp2 );
62 
63  MagFieldEvaluate(yTemp2,Bfield_Temp2);
64 
65  AdvanceHelix( yIn, Bfield_Temp2, h, yAdd2 );
66 
67  for( i = 0; i < nvar; i++ ) {
68  yOut[i] = ( 0.25 * yAdd1[i] + 0.75 * yAdd2[i]);
69  }
70 
71  // NormaliseTangentVector( yOut );
72 }
void AdvanceHelix(const G4double yIn[], G4ThreeVector Bfld, G4double h, G4double yHelix[], G4double yHelix2[]=0)
void MagFieldEvaluate(const G4double y[], G4ThreeVector &Bfield)
int G4int
Definition: G4Types.hh:78
double G4double
Definition: G4Types.hh:76
void DumbStepper(const G4double y[], G4ThreeVector Bfld, G4double h, G4double yout[])
Definition: G4HelixHeum.cc:44