70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
// This code implementation is the intellectual property of
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// the GEANT4 collaboration.
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//
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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 statement,
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// and all its terms.
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//
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// $Id: G4GaussLaguerreQ.hh,v 1.2 1999/11/16 17:30:57 gcosmo Exp $
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// GEANT4 tag $Name: geant4-01-00 $
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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: 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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// ---------------------------------------------------------------------------
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//
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// Constructor for Gauss-Laguerre quadrature method: integral from zero to
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// infinity of pow(x,alpha)*exp(-x)*f(x). The value of nLaguerre 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 called
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// then with any f .
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//
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// G4GaussLaguerreQ( function pFunction,
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// G4double alpha,
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// G4int nLaguerre )
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//
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//
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// -------------------------------------------------------------------------
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//
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// Gauss-Laguerre method for integration of pow(x,alpha)*exp(-x)*pFunction(x)
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// from zero up to infinity. pFunction is evaluated in fNumber points for which
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// fAbscissa[i] and fWeight[i] arrays were created in constructor
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//
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// G4double Integral() const
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// ------------------------------- HISTORY --------------------------------
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//
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// 13.05.97 V.Grichine (Vladimir.Grichine@cern.chz0
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#ifndef G4GAUSSLAGUERREQ_HH
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#define G4GAUSSLAGUERREQ_HH
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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,
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G4double alpha,
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G4int nLaguerre ) ;
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// Methods
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G4double Integral() const ;
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protected:
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private:
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} ;
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#endif
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