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: G4VGaussianQuadrature.hh,v 1.7 2006/06/29 18:59:58 gunter Exp $ |
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28 | // GEANT4 tag $Name: geant4-09-03 $ |
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29 | // |
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30 | // Class description: |
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31 | // |
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32 | // Base Class for realisation of numerical methodes for integration of functions |
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33 | // with signature double f(double) by Gaussian quadrature methods |
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34 | // Roots of ortogonal polynoms and corresponding weights are calculated based on |
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35 | // iteration method (by bisection Newton algorithm). Constant values for initial |
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36 | // approximations were derived from the book: M. Abramowitz, I. Stegun, Handbook |
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37 | // of mathematical functions, DOVER Publications INC, New York 1965 ; chapters 9, |
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38 | // 10, and 22 . |
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39 | // |
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40 | // ---------------------------- Member data: ---------------------------------- |
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41 | // |
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42 | // fFunction - pointer to the function to be integrated |
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43 | // fNumber - the number of points in fAbscissa and fWeight arrays |
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44 | // fAbscissa - array of abscissas, where function will be evaluated |
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45 | // fWeight - array of corresponding weights |
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46 | // |
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47 | // |
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48 | // ---------------------------------------------------------------------- |
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49 | // |
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50 | // Auxiliary function which returns the value of std::log(gamma-function(x)) |
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51 | // |
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52 | // G4double |
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53 | // GammaLogarithm(G4double xx) |
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54 | |
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55 | // ------------------------------------------------------------------------------ |
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56 | // |
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57 | // History: |
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58 | // 18.04.97 V.Grichine ( Vladimir.Grichine@cern.ch ) |
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59 | |
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60 | #ifndef G4VGAUSSIANQUADRATURE_HH |
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61 | #define G4VGAUSSIANQUADRATURE_HH |
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62 | |
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63 | #include "globals.hh" |
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64 | |
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65 | typedef G4double (*function)(G4double) ; |
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66 | |
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67 | class G4VGaussianQuadrature |
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68 | { |
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69 | public: |
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70 | |
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71 | explicit G4VGaussianQuadrature( function pFunction ) ; |
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72 | // Base constructor |
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73 | |
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74 | virtual ~G4VGaussianQuadrature() ; |
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75 | // Virtual destructor |
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76 | |
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77 | G4double GetAbscissa(G4int index) const ; |
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78 | G4double GetWeight(G4int index) const ; |
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79 | G4int GetNumber() const; |
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80 | // Access functions |
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81 | |
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82 | protected: |
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83 | |
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84 | G4double GammaLogarithm(G4double xx) ; |
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85 | |
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86 | // Data members common for GaussianQuadrature family |
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87 | // |
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88 | function fFunction ; |
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89 | G4double* fAbscissa ; |
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90 | G4double* fWeight ; |
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91 | G4int fNumber ; |
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92 | |
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93 | private: |
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94 | |
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95 | G4VGaussianQuadrature(const G4VGaussianQuadrature&); |
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96 | G4VGaussianQuadrature& operator=(const G4VGaussianQuadrature&); |
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97 | }; |
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98 | |
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99 | #endif |
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