| 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 | // |
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| 28 | // $Id: G4RKG3_Stepper.hh,v 1.14 2010/07/23 14:13:09 tnikitin Exp $ |
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| 29 | // GEANT4 tag $Name: field-V09-03-03 $ |
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| 30 | // |
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| 31 | // |
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| 32 | // |
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| 33 | // class G4RKG3_Stepper |
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| 34 | // |
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| 35 | // Class description: |
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| 36 | // |
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| 37 | // Integrator Runga-Kutta Stepper from Geant3. |
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| 38 | // |
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| 39 | // History: |
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| 40 | // - Created. J.Apostolakis, V.Grichine - 30.01.97 |
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| 41 | // ------------------------------------------------------------------- |
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| 42 | |
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| 43 | #ifndef G4RKG3_Stepper_hh |
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| 44 | #define G4RKG3_Stepper_hh |
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| 45 | |
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| 46 | #include "G4Types.hh" |
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| 47 | #include "G4MagIntegratorStepper.hh" |
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| 48 | #include "G4ThreeVector.hh" |
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| 49 | |
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| 50 | class G4Mag_EqRhs; |
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| 51 | |
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| 52 | class G4RKG3_Stepper : public G4MagIntegratorStepper |
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| 53 | { |
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| 54 | public: // with description |
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| 55 | |
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| 56 | G4RKG3_Stepper(G4Mag_EqRhs *EqRhs); |
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| 57 | // Integrate over 6 variables only: position & velocity. |
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| 58 | // Not implemented yet ! |
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| 59 | |
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| 60 | ~G4RKG3_Stepper(); |
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| 61 | |
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| 62 | void Stepper( const G4double yIn[], |
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| 63 | const G4double dydx[], |
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| 64 | G4double h, |
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| 65 | G4double yOut[], |
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| 66 | G4double yErr[] ); |
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| 67 | // The method which must be provided, even if less efficient. |
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| 68 | |
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| 69 | G4double DistChord() const ; |
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| 70 | |
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| 71 | void StepNoErr( const G4double tIn[8], |
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| 72 | const G4double dydx[6], |
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| 73 | G4double Step, |
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| 74 | G4double tOut[8], |
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| 75 | G4double B[3] ); |
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| 76 | // Integrator RK Stepper from G3 with only two field evaluation per |
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| 77 | // Step. It is used in propagation initial Step by small substeps |
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| 78 | // after solution error and delta geometry considerations. |
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| 79 | // B[3] is magnetic field which is passed from substep to substep. |
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| 80 | |
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| 81 | void StepWithEst( const G4double tIn[8], |
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| 82 | const G4double dydx[6], |
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| 83 | G4double Step, |
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| 84 | G4double tOut[8], |
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| 85 | G4double& alpha2, |
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| 86 | G4double& beta2, |
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| 87 | const G4double B1[3], |
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| 88 | G4double B2[3] ); |
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| 89 | // Integrator for RK from G3 with evaluation of error in solution and delta |
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| 90 | // geometry based on naive similarity with the case of uniform magnetic field. |
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| 91 | // B1[3] is input and is the first magnetic field values |
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| 92 | // B2[3] is output and is the final magnetic field values. |
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| 93 | |
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| 94 | public: // without description |
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| 95 | |
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| 96 | G4int IntegratorOrder() const { return 4; } |
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| 97 | |
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| 98 | private: |
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| 99 | |
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| 100 | G4ThreeVector fyInitial, |
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| 101 | fyMidPoint, |
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| 102 | fyFinal; |
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| 103 | G4ThreeVector fpInitial; |
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| 104 | G4ThreeVector BfldIn; |
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| 105 | G4double hStep; |
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| 106 | |
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| 107 | G4Mag_EqRhs* fPtrMagEqOfMot; |
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| 108 | }; |
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| 109 | |
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| 110 | #endif |
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