Geant4 Cross Reference |
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These * 9 // * include a list of copyright holders. 9 // * include a list of copyright holders. * 10 // * 10 // * * 11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing * 12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this * 13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, * 14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its * 15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above * 16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. * 17 // * 17 // * * 18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and * 19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. * 20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or * 21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its * 22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your * 23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. * 24 // ******************************************* 24 // ******************************************************************** 25 // 25 // 26 // G4HelixImplicitEuler implementation << 26 // >> 27 // $Id: G4HelixImplicitEuler.cc 66356 2012-12-18 09:02:32Z gcosmo $ >> 28 // 27 // 29 // 28 // Helix Implicit Euler: 30 // Helix Implicit Euler: 29 // x_1 = x_0 + 1/2 * ( helix(h,t_0,x_0) 31 // x_1 = x_0 + 1/2 * ( helix(h,t_0,x_0) 30 // + helix(h,t_0+h,x_ 32 // + helix(h,t_0+h,x_0+helix(h,t0,x0) ) ) 31 // Second order solver. 33 // Second order solver. 32 // Take the current derivative and add it to 34 // Take the current derivative and add it to the current position. 33 // Take the output and its derivative. Add th 35 // Take the output and its derivative. Add the mean of both derivatives 34 // to form the final output 36 // to form the final output 35 // 37 // 36 // Author: W.Wander <wwc@mit.edu>, 03/11/1998 << 38 // W.Wander <wwc@mit.edu> 12/09/97 >> 39 // 37 // ------------------------------------------- 40 // ------------------------------------------------------------------------- 38 41 39 #include "G4HelixImplicitEuler.hh" 42 #include "G4HelixImplicitEuler.hh" 40 #include "G4ThreeVector.hh" 43 #include "G4ThreeVector.hh" 41 44 42 G4HelixImplicitEuler::G4HelixImplicitEuler(G4M << 43 : G4MagHelicalStepper(EqRhs) << 44 { << 45 } << 46 << 47 G4HelixImplicitEuler::~G4HelixImplicitEuler() << 48 << 49 void 45 void 50 G4HelixImplicitEuler::DumbStepper( const G4dou << 46 G4HelixImplicitEuler::DumbStepper( const G4double yIn[], 51 G4ThreeVect << 47 G4ThreeVector Bfld, 52 G4double << 48 G4double h, 53 G4double << 49 G4double yOut[]) 54 { 50 { 55 const G4int nvar = 6 ; 51 const G4int nvar = 6 ; 56 G4double yTemp[6], yTemp2[6]; 52 G4double yTemp[6], yTemp2[6]; 57 G4ThreeVector Bfld_endpoint; 53 G4ThreeVector Bfld_endpoint; 58 54 >> 55 G4int i; >> 56 59 // Step forward like in the explicit euler c 57 // Step forward like in the explicit euler case 60 // << 61 AdvanceHelix( yIn, Bfld, h, yTemp); 58 AdvanceHelix( yIn, Bfld, h, yTemp); 62 59 63 // now obtain the new field value at the new 60 // now obtain the new field value at the new point 64 // << 65 MagFieldEvaluate(yTemp, Bfld_endpoint); 61 MagFieldEvaluate(yTemp, Bfld_endpoint); 66 62 67 // and also advance along a helix for this f 63 // and also advance along a helix for this field value 68 // << 69 AdvanceHelix( yIn, Bfld_endpoint, h, yTemp2) 64 AdvanceHelix( yIn, Bfld_endpoint, h, yTemp2); 70 65 71 // we take the average << 66 // we take the average 72 // << 67 for( i = 0; i < nvar; i++ ) 73 for( G4int i = 0; i < nvar; ++i ) << 74 { << 75 yOut[i] = 0.5 * ( yTemp[i] + yTemp2[i] ); 68 yOut[i] = 0.5 * ( yTemp[i] + yTemp2[i] ); 76 } << 77 69 78 // NormaliseTangentVector( yOut ); 70 // NormaliseTangentVector( yOut ); 79 } 71 } 80 72