| [831] | 1 | //
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| 2 | // ********************************************************************
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| 3 | // * License and Disclaimer *
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| 4 | // * *
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of *
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and *
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| 7 | // * conditions of the Geant4 Software License, included in the file *
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These *
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| 9 | // * include a list of copyright holders. *
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| 10 | // * *
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| 11 | // * Neither the authors of this software system, nor their employing *
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| 12 | // * institutes,nor the agencies providing financial support for this *
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| 13 | // * work make any representation or warranty, express or implied, *
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| 14 | // * regarding this software system or assume any liability for its *
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| 15 | // * use. Please see the license in the file LICENSE and URL above *
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| 16 | // * for the full disclaimer and the limitation of liability. *
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| 17 | // * *
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| 18 | // * This code implementation is the result of the scientific and *
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| 19 | // * technical work of the GEANT4 collaboration. *
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| 20 | // * By using, copying, modifying or distributing the software (or *
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| 21 | // * any work based on the software) you agree to acknowledge its *
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| 22 | // * use in resulting scientific publications, and indicate your *
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| 23 | // * acceptance of all terms of the Geant4 Software license. *
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| 24 | // ********************************************************************
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| 25 | //
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| 26 | //
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| 27 | // $Id: G4HelixSimpleRunge.cc,v 1.7 2006/06/29 18:24:08 gunter Exp $
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| [850] | 28 | // GEANT4 tag $Name: HEAD $
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| [831] | 29 | //
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| 30 | //
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| 31 | // Simple Runge:
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| 32 | // x_1 = x_0 + h * ( dx( t_0+h/2, x_0 + h/2 * dx( t_0, x_0) ) )
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| 33 | //
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| 34 | // Second order solver.
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| 35 | // Take the derivative at a position to be assumed at the middle of the
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| 36 | // Step and add it to the current position.
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| 37 | //
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| 38 | // W.Wander <wwc@mit.edu> 12/09/97
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| 39 | // -------------------------------------------------------------------------
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| 40 |
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| 41 | #include "G4HelixSimpleRunge.hh"
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| 42 | #include "G4ThreeVector.hh"
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| 43 |
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| 44 | void
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| 45 | G4HelixSimpleRunge::DumbStepper( const G4double yIn[],
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| 46 | G4ThreeVector Bfld,
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| 47 | G4double h,
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| 48 | G4double yOut[])
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| 49 | {
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| 50 | const G4int nvar = 6 ;
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| 51 | G4double yTemp[nvar]; // , yAdd[nvar];
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| 52 | G4ThreeVector Bfld_midpoint;
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| 53 |
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| 54 | AdvanceHelix( yIn, Bfld, 0.5 * h, yTemp);
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| 55 |
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| 56 | // now obtain the new field value at the new point
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| 57 | MagFieldEvaluate(yTemp, Bfld_midpoint);
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| 58 |
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| 59 | AdvanceHelix( yIn, Bfld_midpoint, h, yOut);
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| 60 |
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| 61 | // NormaliseTangentVector( yOut );
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| 62 | }
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