G4GaussHermiteQ Class Reference

#include <G4GaussHermiteQ.hh>

Inheritance diagram for G4GaussHermiteQ:

Collaboration diagram for G4GaussHermiteQ:

Public Member Functions
	G4GaussHermiteQ (function pFunction, G4int nHermite)
G4double	Integral () const
Public Member Functions inherited from G4VGaussianQuadrature
	G4VGaussianQuadrature (function pFunction)
virtual	~G4VGaussianQuadrature ()
G4double	GetAbscissa (G4int index) const
G4double	GetWeight (G4int index) const
G4int	GetNumber () const

Private Member Functions
	G4GaussHermiteQ (const G4GaussHermiteQ &)
G4GaussHermiteQ &	operator= (const G4GaussHermiteQ &)

Additional Inherited Members
Protected Member Functions inherited from G4VGaussianQuadrature
G4double	GammaLogarithm (G4double xx)
Protected Attributes inherited from G4VGaussianQuadrature
function	fFunction
G4double *	fAbscissa
G4double *	fWeight
G4int	fNumber

Detailed Description

Definition at line 60 of file G4GaussHermiteQ.hh.

Constructor & Destructor Documentation

G4GaussHermiteQ() [1/2]

G4GaussHermiteQ::G4GaussHermiteQ	(	function	pFunction,
		G4int	nHermite
	)

Definition at line 37 of file G4GaussHermiteQ.cc.

   : G4VGaussianQuadrature(pFunction)
{
   const G4double tolerance = 1.0e-12 ;
   const G4int maxNumber = 12 ;
   
   G4int i=1, j=1, k=1 ;
   G4double newton0=0.;
   G4double newton1=0.0, temp1=0.0, temp2=0.0, temp3=0.0, temp=0.0 ;
   G4double piInMinusQ = std::pow(pi,-0.25) ; // 1.0/std::sqrt(std::sqrt(pi)) ??

   fNumber = (nHermite +1)/2 ;
   fAbscissa = new G4double[fNumber] ;
   fWeight   = new G4double[fNumber] ;

   for(i=1;i<=fNumber;i++)
   {
      if(i == 1)
      {
         newton0 = std::sqrt((G4double)(2*nHermite + 1)) - 
                   1.85575001*std::pow((G4double)(2*nHermite + 1),-0.16666999) ;
      }
      else if(i == 2)
      {
         newton0 -= 1.14001*std::pow((G4double)nHermite,0.425999)/newton0 ;
      }
      else if(i == 3)
      {
         newton0 = 1.86002*newton0 - 0.86002*fAbscissa[0] ;
      }
      else if(i == 4)
      {
         newton0 = 1.91001*newton0 - 0.91001*fAbscissa[1] ;
      }
      else 
      {
         newton0 = 2.0*newton0 - fAbscissa[i - 3] ;
      }
      for(k=1;k<=maxNumber;k++)
      {
         temp1 = piInMinusQ ;
         temp2 = 0.0 ;
         for(j=1;j<=nHermite;j++)
         {
            temp3 = temp2 ;
            temp2 = temp1 ;
            temp1 = newton0*std::sqrt(2.0/j)*temp2
                  - std::sqrt(((G4double)(j - 1))/j)*temp3 ;
         }
         temp = std::sqrt((G4double)2*nHermite)*temp2 ;
         newton1 = newton0 ;
         newton0 = newton1 - temp1/temp ;
         if(std::fabs(newton0 - newton1) <= tolerance) 
         {
            break ;
         }
      }
      if(k > maxNumber)
      {
         G4Exception("G4GaussHermiteQ::G4GaussHermiteQ()",
                     "OutOfRange", FatalException,
                     "Too many iterations in Gauss-Hermite constructor.") ;
      }
      fAbscissa[i-1] =  newton0 ;
      fWeight[i-1] = 2.0/(temp*temp) ;
   }
}

Here is the call graph for this function:

G4GaussHermiteQ() [2/2]

G4GaussHermiteQ::G4GaussHermiteQ ( const G4GaussHermiteQ &  )

private

Member Function Documentation

Integral()

G4double G4GaussHermiteQ::Integral

(

)

const

Definition at line 112 of file G4GaussHermiteQ.cc.

{
   G4double integral = 0.0 ;
   for(G4int i=0;i<fNumber;i++)
   {
      integral += fWeight[i]*(fFunction(fAbscissa[i])
                + fFunction(-fAbscissa[i])) ;
   }
   return integral ;
}

operator=()

G4GaussHermiteQ& G4GaussHermiteQ::operator= ( const G4GaussHermiteQ &  )

private

---

The documentation for this class was generated from the following files:

• G4GaussHermiteQ.hh
• G4GaussHermiteQ.cc