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 // Class description: 00030 // 00031 // Class for realisation of simple numerical methodes for integration of 00032 // functions with signature: double f(double). The methods based mainly on 00033 // algorithms given in the book : 00034 // An introduction to NUMERICAL METHODS IN C++, 00035 // B.H. Flowers, Claredon Press, Oxford, 1995. 00036 // 00037 // --------------------------- Member data ---------------------------- 00038 // 00039 // fFunction - pointer to the function to be integrated 00040 // fTolerance - accuracy of integration in Adaptive Gauss method 00041 // fMaxDepth = 100 - constant maximum iteration depth for 00042 // Adaptive Gauss method 00043 // 00044 // --------------------------- Methods -------------------------------- 00045 // 00046 // Trapezoidal, MidPoint, Gauss and Simpson(double a,double b,int n) 00047 // - integrate function pointed by fFunction from a to b by n iterations, 00048 // i.e. with Step (b-a)/n according to the correspondent method. 00049 // 00050 // AdaptGausIntegration(double a, double b) 00051 // - integrate function from a to be with accuracy <= fTolerance 00052 00053 // ----------------------------- History ------------------------------ 00054 // 00055 // 26.03.97 V.Grichine ( Vladimir.Grichine@cern.ch ) 00056 00057 #ifndef G4SIMPLEINTEGRATION_HH 00058 #define G4SIMPLEINTEGRATION_HH 00059 00060 #include "G4Types.hh" 00061 00062 typedef G4double (*function)(G4double) ; 00063 00064 class G4SimpleIntegration 00065 { 00066 public: 00067 00068 explicit G4SimpleIntegration( function pFunction ) ; 00069 00070 G4SimpleIntegration( function pFunction, 00071 G4double pTolerance ) ; 00072 00073 ~G4SimpleIntegration() ; 00074 00075 // Simple integration methods 00076 00077 G4double Trapezoidal(G4double xInitial, 00078 G4double xFinal, 00079 G4int iterationNumber ) ; 00080 00081 G4double MidPoint(G4double xInitial, 00082 G4double xFinal, 00083 G4int iterationNumber ) ; 00084 00085 G4double Gauss(G4double xInitial, 00086 G4double xFinal, 00087 G4int iterationNumber ) ; 00088 00089 G4double Simpson(G4double xInitial, 00090 G4double xFinal, 00091 G4int iterationNumber ) ; 00092 00093 // Adaptive Gauss integration with accuracy ~ fTolerance 00094 00095 G4double AdaptGaussIntegration( G4double xInitial, 00096 G4double xFinal ) ; 00097 00098 protected: 00099 00100 G4double Gauss( G4double xInitial, 00101 G4double xFinal ) ; 00102 00103 void AdaptGauss( G4double xInitial, 00104 G4double xFinal, 00105 G4double& sum, 00106 G4int& depth ) ; 00107 private: 00108 00109 G4SimpleIntegration(const G4SimpleIntegration&); 00110 G4SimpleIntegration& operator=(const G4SimpleIntegration&); 00111 // Private copy constructor and assignment operator. 00112 00113 private: 00114 00115 function fFunction ; 00116 G4double fTolerance ; 00117 static G4int fMaxDepth ; 00118 }; 00119 00120 #endif