Gabriele Cosmo
109 lines
3.9 KiB
C++
109 lines
3.9 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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//
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// $Id: G4VGaussianQuadrature.hh,v 1.4 2001/07/11 10:00:40 gunter Exp $
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// GEANT4 tag $Name: geant4-05-00 $
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//
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// Class description:
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//
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// Base Class for realisation of numerical methodes for integration of functions
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// with signature double f(double) by Gaussian quadrature methods
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// Roots of ortogonal polynoms and corresponding weights are calculated based on
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// iteration method (by bisection Newton algorithm). Constant values for initial
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// approximations were derived from the book: M. Abramowitz, I. Stegun, Handbook
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// of mathematical functions, DOVER Publications INC, New York 1965 ; chapters 9,
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// 10, and 22 .
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//
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// ---------------------------- Member data: ----------------------------------
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//
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// fFunction - pointer to the function to be integrated
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// fNumber - the number of points in fAbscissa and fWeight arrays
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// fAbscissa - array of abscissas, where function will be evaluated
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// fWeight - array of corresponding weights
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//
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//
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// ----------------------------------------------------------------------
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//
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// Auxiliary function which returns the value of log(gamma-function(x))
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//
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// G4double
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// GammaLogarithm(G4double xx)
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// ------------------------------------------------------------------------------
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//
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// History:
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// 18.04.97 V.Grichine ( Vladimir.Grichine@cern.ch )
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#ifndef G4VGAUSSIANQUADRATURE_HH
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#define G4VGAUSSIANQUADRATURE_HH
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#include "globals.hh"
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typedef G4double (*function)(G4double) ;
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class G4VGaussianQuadrature
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{
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public:
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// Base constructor
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G4VGaussianQuadrature( function pFunction ) ;
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// Virtual destructor
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virtual ~G4VGaussianQuadrature() ;
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// Access functions:
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G4double GetAbscissa(G4int index) const ;
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G4double GetWeight(G4int index) const ;
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G4int GetNumber() const { return fNumber ; }
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// Methods:
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// virtual G4double DefiniteIntegral( G4double a,
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// G4double b ) const = 0 ;
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// virtual G4double Integral() const = 0 ;
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protected:
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G4double GammaLogarithm(G4double xx) ;
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// Data members common for GaussianQuadrature family
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function fFunction ;
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G4double* fAbscissa ;
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G4double* fWeight ;
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G4int fNumber ;
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private:
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G4VGaussianQuadrature(const G4VGaussianQuadrature&);
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G4VGaussianQuadrature& operator=(const G4VGaussianQuadrature&);
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};
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#endif
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