include/Geant4/G4HelixImplicitEuler.hh

0001 //
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0025 //
0026 // G4HelixImplicitEuler
0027 //
0028 // Class description:
0029 //
0030 //  Helix Implicit Euler stepper for magnetic field:
0031 //        x_1 = x_0 + 1/2 * ( helix(h,t_0,x_0)
0032 //                          + helix(h,t_0+h,x_0+helix(h,t0,x0) ) )
0033 //  Second order solver.
0034 //  Take the current derivative and add it to the current position.
0035 //  Take the output and its derivative. Add the mean of both derivatives
0036 //  to form the final output.
0037
0038 // Author: W.Wander <wwc@mit.edu>, 03/11/1998
0039 // -------------------------------------------------------------------
0040 #ifndef G4HELIXIMPLICITEULER_HH
0041 #define G4HELIXIMPLICITEULER_HH
0042
0043 #include "G4MagHelicalStepper.hh"
0044
0045 class G4HelixImplicitEuler : public G4MagHelicalStepper
0046 {
0047   public:
0048
0049     G4HelixImplicitEuler(G4Mag_EqRhs *EqRhs);
0050    ~G4HelixImplicitEuler() override;
0051
0052     void DumbStepper( const G4double y[],
0053                             G4ThreeVector Bfld,
0054                             G4double      h,
0055                             G4double      yout[] ) override;
0056
0057     inline G4int IntegratorOrder() const override { return 2; }
0058 };
0059
0060 #endif