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 // $Id$ 00028 // 00029 // ---------------------------------------------------------------------- 00030 // Class G4WeightWindowAlgorithm 00031 // 00032 // Class description: 00033 // Implementation of a weight window algorithm. 00034 // The arguments in the constructor configure the algorithm: 00035 // - upperLimitFaktor: the factor defining the upper weight limit 00036 // W_u = upperLimitFaktor * W_l (W_l lower weight bound) 00037 // - survivalFaktor: used in calculating the survival weight 00038 // W_s = survivalFaktor * W_l 00039 // - maxNumberOfSplits: the maximal number of splits allowed 00040 // to be created in one go, and the reciprocal of the minimal 00041 // survival probability in case of Russian roulette 00042 // 00043 // In case of upperLimitFaktor=survivalFaktor=1 the algorithm 00044 // becomes the expected weight algorithm of the importance sampling 00045 // technique. 00046 // 00047 // see also G4VWeightWindowAlgorithm. 00048 // 00049 00050 // Author: Michael Dressel (Michael.Dressel@cern.ch) 00051 // ---------------------------------------------------------------------- 00052 #ifndef G4WeightWindowAlgorithm_hh 00053 #define G4WeightWindowAlgorithm_hh G4WeightWindowAlgorithm_hh 00054 00055 #include "G4Nsplit_Weight.hh" 00056 #include "G4VWeightWindowAlgorithm.hh" 00057 00058 class G4WeightWindowAlgorithm : public G4VWeightWindowAlgorithm 00059 { 00060 00061 public: // with description 00062 00063 G4WeightWindowAlgorithm(G4double upperLimitFaktor = 5, 00064 G4double survivalFaktor = 3, 00065 G4int maxNumberOfSplits = 5); 00066 00067 virtual ~G4WeightWindowAlgorithm(); 00068 00069 virtual G4Nsplit_Weight Calculate(G4double init_w, 00070 G4double lowerWeightBound) const; 00071 // calculate number of tracks and their weight according 00072 // to the initial track weight and the lower energy bound 00073 00074 private: 00075 G4double fUpperLimitFaktor; 00076 G4double fSurvivalFaktor; 00077 G4int fMaxNumberOfSplits; 00078 }; 00079 00080 #endif