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25 // 25 //
26 // G4ErrorMag_UsualEqRhs implementation <<
27 // 26 //
28 // Created: P.Arce, September 2004. << 27 // $Id: G4ErrorMag_UsualEqRhs.cc,v 1.1 2007/05/16 12:54:02 gcosmo Exp $
>> 28 // GEANT4 tag $Name: geant4-09-01 $
>> 29 //
>> 30 //
>> 31 // --------------------------------------------------------------------
>> 32 // GEANT 4 class implementation file
29 // ------------------------------------------- 33 // --------------------------------------------------------------------
30 34
31 #include "G4ErrorMag_UsualEqRhs.hh" 35 #include "G4ErrorMag_UsualEqRhs.hh"
32 #include "G4ErrorPropagatorData.hh" 36 #include "G4ErrorPropagatorData.hh"
33 37
34 //-------------------------------------------- 38 //---------------------------------------------------------------------
35 39
36 G4ErrorMag_UsualEqRhs::G4ErrorMag_UsualEqRhs( 40 G4ErrorMag_UsualEqRhs::G4ErrorMag_UsualEqRhs( G4MagneticField* MagField )
37 : G4Mag_UsualEqRhs( MagField ) 41 : G4Mag_UsualEqRhs( MagField )
38 { 42 {
39 } 43 }
40 44
41 G4ErrorMag_UsualEqRhs::~G4ErrorMag_UsualEqRhs( << 45 G4ErrorMag_UsualEqRhs::~G4ErrorMag_UsualEqRhs()
>> 46 {
>> 47 }
42 48
43 //-------------------------------------------- 49 //---------------------------------------------------------------------
44 <<
45 void 50 void
46 G4ErrorMag_UsualEqRhs::EvaluateRhsGivenB( cons 51 G4ErrorMag_UsualEqRhs::EvaluateRhsGivenB( const G4double y[],
47 cons 52 const G4double B[3],
48 53 G4double dydx[] ) const
49 { 54 {
50 55
51 G4Mag_UsualEqRhs::EvaluateRhsGivenB(y, B, dy 56 G4Mag_UsualEqRhs::EvaluateRhsGivenB(y, B, dydx );
52 57
53 if(G4ErrorPropagatorData::GetErrorPropagator 58 if(G4ErrorPropagatorData::GetErrorPropagatorData()->GetMode()
54 == G4ErrorMode_PropBackwards) 59 == G4ErrorMode_PropBackwards)
55 { 60 {
56 G4double momentum_mag_square = sqr(y[3]) + 61 G4double momentum_mag_square = sqr(y[3]) + sqr(y[4]) + sqr(y[5]);
57 G4double inv_momentum_magnitude = 1.0 / st 62 G4double inv_momentum_magnitude = 1.0 / std::sqrt( momentum_mag_square );
58 63
59 G4double cof = FCof()*inv_momentum_magnitu 64 G4double cof = FCof()*inv_momentum_magnitude;
60 65
61 dydx[3] = cof*(y[4]*(-B[2]) - y[5]*(-B[1]) 66 dydx[3] = cof*(y[4]*(-B[2]) - y[5]*(-B[1])) ;
62 dydx[4] = cof*(y[5]*(-B[0]) - y[3]*(-B[2]) 67 dydx[4] = cof*(y[5]*(-B[0]) - y[3]*(-B[2])) ;
63 dydx[5] = cof*(y[3]*(-B[1]) - y[4]*(-B[0]) 68 dydx[5] = cof*(y[3]*(-B[1]) - y[4]*(-B[0])) ;
64 } 69 }
65 return; 70 return;
66 } 71 }
67 72