G4GaussLaguerreQ.hh

Go to the documentation of this file.

//
// ********************************************************************
// * License and Disclaimer                                           *
// *                                                                  *
// * The  Geant4 software  is  copyright of the Copyright Holders  of *
// * the Geant4 Collaboration.  It is provided  under  the terms  and *
// * conditions of the Geant4 Software License,  included in the file *
// * LICENSE and available at  http://cern.ch/geant4/license .  These *
// * include a list of copyright holders.                             *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.  Please see the license in the file  LICENSE  and URL above *
// * for the full disclaimer and the limitation of liability.         *
// *                                                                  *
// * This  code  implementation is the result of  the  scientific and *
// * technical work of the GEANT4 collaboration.                      *
// * By using,  copying,  modifying or  distributing the software (or *
// * any work based  on the software)  you  agree  to acknowledge its *
// * use  in  resulting  scientific  publications,  and indicate your *
// * acceptance of all terms of the Geant4 Software license.          *
// ********************************************************************
//
//
//
// Class description:
//
// Class for realization of Gauss-Laguerre quadrature method
// Roots of ortogonal polynoms and corresponding weights are calculated based on
// iteration method (by bisection Newton algorithm). Constant values for initial
// approximations were derived from the book:
//   M. Abramowitz, I. Stegun, Handbook of mathematical functions,
//   DOVER Publications INC, New York 1965 ; chapters 9, 10, and 22.
 
// Author: V.Grichine, 13.05.1997
// --------------------------------------------------------------------
#ifndef G4GAUSSLAGUERREQ_HH
#define G4GAUSSLAGUERREQ_HH 1
 
#include "G4VGaussianQuadrature.hh"
 
class G4GaussLaguerreQ : public G4VGaussianQuadrature
{
 public:
  G4GaussLaguerreQ(function pFunction, G4double alpha, G4int nLaguerre);
  // Constructor for Gauss-Laguerre quadrature method: integral from zero to
  // infinity of std::pow(x,alpha)*std::exp(-x)*f(x). The value of nLaguerre
  // sets the accuracy.
  // The constructor creates arrays fAbscissa[0,..,nLaguerre-1] and
  // fWeight[0,..,nLaguerre-1] . The function GaussLaguerre(f) should be
  // called then with any f.
 
  G4GaussLaguerreQ(const G4GaussLaguerreQ&) = delete;
  G4GaussLaguerreQ& operator=(const G4GaussLaguerreQ&) = delete;
 
  G4double Integral() const;
  // Gauss-Laguerre method for integration of
  // std::pow(x,alpha)*std::exp(-x)*pFunction(x) from zero up to infinity.
  // pFunction is evaluated in fNumber points for which fAbscissa[i] and
  // fWeight[i] arrays were created in constructor.
};
 
#endif