[833] | 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: G4GaussLegendreQ.hh,v 1.6 2006/06/29 18:59:42 gunter Exp $ |
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[1228] | 28 | // GEANT4 tag $Name: geant4-09-03 $ |
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[833] | 29 | // |
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| 30 | // Class description: |
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| 31 | // |
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| 32 | // Class for Gauss-Legendre integration method |
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| 33 | // Roots of ortogonal polynoms and corresponding weights are calculated based on |
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| 34 | // iteration method (by bisection Newton algorithm). Constant values for initial |
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| 35 | // approximations were derived from the book: M. Abramowitz, I. Stegun, Handbook |
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| 36 | // of mathematical functions, DOVER Publications INC, New York 1965 ; chapters 9, |
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| 37 | // 10, and 22 . |
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| 38 | // |
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| 39 | // ------------------------- CONSTRUCTORS: ------------------------------- |
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| 40 | // |
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| 41 | // Constructor for GaussLegendre quadrature method. The value nLegendre set the |
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| 42 | // accuracy required, i.e the number of points where the function pFunction will |
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| 43 | // be evaluated during integration. The constructor creates the arrays for |
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| 44 | // abscissas and weights that used in Gauss-Legendre quadrature method. |
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| 45 | // The values a and b are the limits of integration of the pFunction. |
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| 46 | // |
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| 47 | // G4GaussLegendreQ( function pFunction, |
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| 48 | // G4int nLegendre ) |
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| 49 | // |
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| 50 | // -------------------------- METHODS: --------------------------------------- |
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| 51 | // |
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| 52 | // Returns the integral of the function to be pointed by fFunction between a and b, |
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| 53 | // by 2*fNumber point Gauss-Legendre integration: the function is evaluated exactly |
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| 54 | // 2*fNumber Times at interior points in the range of integration. Since the weights |
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| 55 | // and abscissas are, in this case, symmetric around the midpoint of the range of |
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| 56 | // integration, there are actually only fNumber distinct values of each. |
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| 57 | // |
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| 58 | // G4double Integral(G4double a, G4double b) const |
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| 59 | // |
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| 60 | // ----------------------------------------------------------------------- |
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| 61 | // |
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| 62 | // Returns the integral of the function to be pointed by fFunction between a and b, |
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| 63 | // by ten point Gauss-Legendre integration: the function is evaluated exactly |
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| 64 | // ten Times at interior points in the range of integration. Since the weights |
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| 65 | // and abscissas are, in this case, symmetric around the midpoint of the range of |
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| 66 | // integration, there are actually only five distinct values of each |
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| 67 | // |
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| 68 | // G4double |
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| 69 | // QuickIntegral(G4double a, G4double b) const |
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| 70 | // |
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| 71 | // --------------------------------------------------------------------- |
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| 72 | // |
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| 73 | // Returns the integral of the function to be pointed by fFunction between a and b, |
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| 74 | // by 96 point Gauss-Legendre integration: the function is evaluated exactly |
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| 75 | // ten Times at interior points in the range of integration. Since the weights |
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| 76 | // and abscissas are, in this case, symmetric around the midpoint of the range of |
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| 77 | // integration, there are actually only five distinct values of each |
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| 78 | // |
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| 79 | // G4double |
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| 80 | // AccurateIntegral(G4double a, G4double b) const |
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| 81 | |
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| 82 | // ------------------------------- HISTORY -------------------------------- |
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| 83 | // |
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| 84 | // 13.05.97 V.Grichine (Vladimir.Grichine@cern.chz0 |
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| 85 | |
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| 86 | #ifndef G4GAUSSLEGENDREQ_HH |
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| 87 | #define G4GAUSSLEGENDREQ_HH |
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| 88 | |
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| 89 | #include "G4VGaussianQuadrature.hh" |
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| 90 | |
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| 91 | class G4GaussLegendreQ : public G4VGaussianQuadrature |
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| 92 | { |
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| 93 | public: |
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| 94 | explicit G4GaussLegendreQ( function pFunction ) ; |
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| 95 | |
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| 96 | |
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| 97 | G4GaussLegendreQ( function pFunction, |
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| 98 | G4int nLegendre ) ; |
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| 99 | |
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| 100 | // Methods |
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| 101 | |
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| 102 | G4double Integral(G4double a, G4double b) const ; |
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| 103 | |
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| 104 | G4double QuickIntegral(G4double a, G4double b) const ; |
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| 105 | |
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| 106 | G4double AccurateIntegral(G4double a, G4double b) const ; |
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| 107 | |
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| 108 | private: |
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| 109 | |
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| 110 | G4GaussLegendreQ(const G4GaussLegendreQ&); |
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| 111 | G4GaussLegendreQ& operator=(const G4GaussLegendreQ&); |
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| 112 | }; |
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| 113 | |
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| 114 | #endif |
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