00001 // 00002 // ******************************************************************** 00003 // * License and Disclaimer * 00004 // * * 00005 // * The Geant4 software is copyright of the Copyright Holders of * 00006 // * the Geant4 Collaboration. It is provided under the terms and * 00007 // * conditions of the Geant4 Software License, included in the file * 00008 // * LICENSE and available at http://cern.ch/geant4/license . These * 00009 // * include a list of copyright holders. * 00010 // * * 00011 // * Neither the authors of this software system, nor their employing * 00012 // * institutes,nor the agencies providing financial support for this * 00013 // * work make any representation or warranty, express or implied, * 00014 // * regarding this software system or assume any liability for its * 00015 // * use. Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // 00027 // $Id: G4HelixImplicitEuler.hh 69786 2013-05-15 09:38:51Z gcosmo $ 00028 // 00029 // 00030 // class G4HelixImplicitEuler 00031 // 00032 // Class description: 00033 // 00034 // Helix Implicit Euler stepper for magnetic field: 00035 // x_1 = x_0 + 1/2 * ( helix(h,t_0,x_0) 00036 // + helix(h,t_0+h,x_0+helix(h,t0,x0) ) ) 00037 // Second order solver. 00038 // Take the current derivative and add it to the current position. 00039 // Take the output and its derivative. Add the mean of both derivatives 00040 // to form the final output. 00041 00042 // History: 00043 // - Created. W.Wander <wwc@mit.edu>, 03/11/98 00044 // ------------------------------------------------------------------- 00045 00046 #ifndef G4HELIXIMPLICITEULER_HH 00047 #define G4HELIXIMPLICITEULER_HH 00048 00049 #include "G4MagHelicalStepper.hh" 00050 00051 class G4HelixImplicitEuler : public G4MagHelicalStepper 00052 { 00053 00054 public: // with description 00055 00056 G4HelixImplicitEuler(G4Mag_EqRhs *EqRhs) 00057 : G4MagHelicalStepper(EqRhs) {} 00058 00059 ~G4HelixImplicitEuler() {} 00060 00061 void DumbStepper( const G4double y[], 00062 G4ThreeVector Bfld, 00063 G4double h, 00064 G4double yout[]); 00065 00066 public: // without description 00067 00068 G4int IntegratorOrder() const { return 2; } 00069 }; 00070 00071 #endif /* G4HELIXIMPLICITEULER_HH */