#include <Gamma.hh>

Public Member Functions
	MyGamma ()

	~MyGamma ()

double	Gamma (double z)

double	Gamma (double a, double x)

Detailed Description

Definition at line 46 of file Gamma.hh.

Constructor & Destructor Documentation

◆ MyGamma()

MyGamma::MyGamma ( )

Definition at line 37 of file Gamma.cc.

37{}

◆ ~MyGamma()

MyGamma::~MyGamma ( )

Definition at line 39 of file Gamma.cc.

39{}

Member Function Documentation

◆ Gamma() [1/2]

double MyGamma::Gamma	(	double	a,
		double	x
	)

Definition at line 60 of file Gamma.cc.

{
  // Computation of the incomplete gamma function P(a,x)
  //
  // The algorithm is based on the formulas and code as denoted in
  // Numerical Recipes 2nd ed. on p. 210-212 (W.H.Press et al.).
  //
  //--- Nve 14-nov-1998 UU-SAP Utrecht
  
  if (a <= 0 || x <= 0) return 0;
  
  if (x < (a+1)) return GamSer(a,x);
  else           return GamCf(a,x);
}

◆ Gamma() [2/2]

double MyGamma::Gamma ( double z )

Definition at line 42 of file Gamma.cc.

{
  // Computation of gamma(z) for all z>0.
  //
  // The algorithm is based on the article by C.Lanczos [1] as denoted in
  // Numerical Recipes 2nd ed. on p. 207 (W.H.Press et al.).
  //
  // [1] C.Lanczos, SIAM Journal of Numerical Analysis B1 (1964), 86.
  //
  //--- Nve 14-nov-1998 UU-SAP Utrecht
  
  if (z<=0) return 0;
  
  double v = LnGamma(z);
  return std::exp(v);
}

Referenced by GVFlashShowerParameterisation::gam().

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