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: G4ImplicitEuler.hh 69786 2013-05-15 09:38:51Z gcosmo $ 00028 // 00029 // 00030 // class G4ImplicitEuler 00031 // 00032 // Class description: 00033 // 00034 // Implicit Euler stepper for magnetic field: 00035 // x_1 = x_0 + h/2 * ( dx(t_0,x_0) + dx(t_0+h,x_0+h*dx(t_0,x_0) ) ) 00036 // 00037 // Second order solver. 00038 // Takes the current derivative and add it to the current position. 00039 // Takes the output and its derivative. Adds the mean of both 00040 // derivatives to form the final output. 00041 00042 // W. Wander <wwc@mit.edu> 12/09/97 00043 // ------------------------------------------------------------------- 00044 00045 #ifndef G4IMPLICITEULER_HH 00046 #define G4IMPLICITEULER_HH 00047 00048 #include "G4MagErrorStepper.hh" 00049 00050 class G4ImplicitEuler : public G4MagErrorStepper 00051 { 00052 00053 public: // with description 00054 00055 G4ImplicitEuler(G4EquationOfMotion *EqRhs, G4int numberOfVariables = 6) ; 00056 ~G4ImplicitEuler(); 00057 00058 void DumbStepper( const G4double y[] , 00059 const G4double dydx[] , 00060 G4double h , 00061 G4double yout[] ) ; 00062 00063 public: // without description 00064 00065 G4int IntegratorOrder() const { return 2 ; } ; 00066 00067 private: 00068 00069 G4double* dydxTemp; 00070 G4double* yTemp; 00071 // Temporaries, created to avoid new/delete on every call 00072 }; 00073 00074 #endif /* G4IMPLICITEULER_HH */