| 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: G4WeightWindowAlgorithm.hh,v 1.7 2006/06/29 18:16:59 gunter Exp $ |
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| 28 | // GEANT4 tag $Name: geant4-09-02-ref-02 $ |
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| 29 | // |
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| 30 | // ---------------------------------------------------------------------- |
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| 31 | // Class G4WeightWindowAlgorithm |
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| 32 | // |
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| 33 | // Class description: |
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| 34 | // Implementation of a weight window algorithm. |
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| 35 | // The arguments in the constructor configure the algorithm: |
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| 36 | // - upperLimitFaktor: the factor defining the upper weight limit |
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| 37 | // W_u = upperLimitFaktor * W_l (W_l lower weight bound) |
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| 38 | // - survivalFaktor: used in calculating the survival weight |
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| 39 | // W_s = survivalFaktor * W_l |
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| 40 | // - maxNumberOfSplits: the maximal number of splits allowed |
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| 41 | // to be created in one go, and the reciprocal of the minimal |
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| 42 | // survival probability in case of Russian roulette |
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| 43 | // |
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| 44 | // In case of upperLimitFaktor=survivalFaktor=1 the algorithm |
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| 45 | // becomes the expected weight algorithm of the importance sampling |
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| 46 | // technique. |
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| 47 | // |
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| 48 | // see also G4VWeightWindowAlgorithm. |
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| 49 | // |
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| 50 | |
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| 51 | // Author: Michael Dressel (Michael.Dressel@cern.ch) |
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| 52 | // ---------------------------------------------------------------------- |
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| 53 | #ifndef G4WeightWindowAlgorithm_hh |
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| 54 | #define G4WeightWindowAlgorithm_hh G4WeightWindowAlgorithm_hh |
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| 55 | |
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| 56 | #include "G4Nsplit_Weight.hh" |
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| 57 | #include "G4VWeightWindowAlgorithm.hh" |
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| 58 | |
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| 59 | class G4WeightWindowAlgorithm : public G4VWeightWindowAlgorithm |
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| 60 | { |
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| 61 | |
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| 62 | public: // with description |
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| 63 | |
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| 64 | G4WeightWindowAlgorithm(G4double upperLimitFaktor = 5, |
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| 65 | G4double survivalFaktor = 3, |
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| 66 | G4int maxNumberOfSplits = 5); |
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| 67 | |
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| 68 | virtual ~G4WeightWindowAlgorithm(); |
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| 69 | |
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| 70 | virtual G4Nsplit_Weight Calculate(G4double init_w, |
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| 71 | G4double lowerWeightBound) const; |
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| 72 | // calculate number of tracks and their weight according |
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| 73 | // to the initial track weight and the lower energy bound |
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| 74 | |
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| 75 | private: |
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| 76 | G4double fUpperLimitFaktor; |
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| 77 | G4double fSurvivalFaktor; |
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| 78 | G4int fMaxNumberOfSplits; |
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| 79 | }; |
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| 80 | |
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| 81 | #endif |
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