Gabriele Cosmo
66 lines
3.1 KiB
C++
66 lines
3.1 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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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. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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//
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//
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// Class description:
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//
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// Class for realization of Gauss-Laguerre quadrature method
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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:
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// M. Abramowitz, I. Stegun, Handbook of mathematical functions,
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// DOVER Publications INC, New York 1965 ; chapters 9, 10, and 22.
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// Author: V.Grichine, 13.05.1997
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// --------------------------------------------------------------------
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#ifndef G4GAUSSLAGUERREQ_HH
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#define G4GAUSSLAGUERREQ_HH 1
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#include "G4VGaussianQuadrature.hh"
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class G4GaussLaguerreQ : public G4VGaussianQuadrature
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{
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public:
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G4GaussLaguerreQ(function pFunction, G4double alpha, G4int nLaguerre);
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// Constructor for Gauss-Laguerre quadrature method: integral from zero to
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// infinity of std::pow(x,alpha)*std::exp(-x)*f(x). The value of nLaguerre
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// sets the accuracy.
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// The constructor creates arrays fAbscissa[0,..,nLaguerre-1] and
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// fWeight[0,..,nLaguerre-1] . The function GaussLaguerre(f) should be
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// called then with any f.
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G4GaussLaguerreQ(const G4GaussLaguerreQ&) = delete;
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G4GaussLaguerreQ& operator=(const G4GaussLaguerreQ&) = delete;
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G4double Integral() const;
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// Gauss-Laguerre method for integration of
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// std::pow(x,alpha)*std::exp(-x)*pFunction(x) from zero up to infinity.
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// pFunction is evaluated in fNumber points for which fAbscissa[i] and
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// fWeight[i] arrays were created in constructor.
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};
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#endif
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