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: G4HelixHeum.cc 69786 2013-05-15 09:38:51Z gcosmo $ 00028 // 00029 // 00030 // Simple Heum: 00031 // x_1 = x_0 + h * 00032 // 1/4 * dx(t0,x0) + 00033 // 3/4 * dx(t0+2/3*h, x0+2/3*h*(dx(t0+h/3,x0+h/3*dx(t0,x0)))) 00034 // 00035 // Third order solver. 00036 // 00037 // W.Wander <wwc@mit.edu> 12/09/97 00038 // ------------------------------------------------------------------- 00039 00040 #include "G4HelixHeum.hh" 00041 #include "G4ThreeVector.hh" 00042 00043 void 00044 G4HelixHeum::DumbStepper( const G4double yIn[], 00045 G4ThreeVector Bfld, 00046 G4double h, 00047 G4double yOut[]) 00048 { 00049 const G4int nvar = 6 ; 00050 00051 G4ThreeVector Bfield_Temp, Bfield_Temp2; 00052 G4double yTemp[6], yAdd1[6], yAdd2[6] , yTemp2[6]; 00053 00054 G4int i; 00055 00056 AdvanceHelix( yIn, Bfld, h, yAdd1 ); 00057 00058 AdvanceHelix( yIn, Bfld, h/3.0, yTemp ); 00059 MagFieldEvaluate(yTemp,Bfield_Temp); 00060 00061 AdvanceHelix( yIn, Bfield_Temp, (2.0 / 3.0) * h, yTemp2 ); 00062 00063 MagFieldEvaluate(yTemp2,Bfield_Temp2); 00064 00065 AdvanceHelix( yIn, Bfield_Temp2, h, yAdd2 ); 00066 00067 for( i = 0; i < nvar; i++ ) { 00068 yOut[i] = ( 0.25 * yAdd1[i] + 0.75 * yAdd2[i]); 00069 } 00070 00071 // NormaliseTangentVector( yOut ); 00072 }