MathTools.cxx File Reference

#include "ReweightUtils/MathTools.h"
#include <cmath>

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Macros
#define	MathTools_cxx

Functions
double	ln_factorial (unsigned int value)
	Logarithmic factorial (precise).
double	ln_factorialApp (unsigned int value)
	Logarithmic factorial (approximative).

Macro Definition Documentation

MathTools_cxx

#define MathTools_cxx

Definition at line 5 of file MathTools.cxx.

Function Documentation

ln_factorial()

double ln_factorial

(

unsigned int

value

)

Logarithmic factorial (precise).

Definition at line 10 of file MathTools.cxx.

                                        {
  double result = 0.;
  for (int k = value ; k > 0 ; --k) {
    result += std::log(k);
  }
  return result;
}

ln_factorialApp()

double ln_factorialApp

(

unsigned int

value

)

Logarithmic factorial (approximative).

Definition at line 18 of file MathTools.cxx.

                                           {
  return 0.5*std::log(1.04719755119659763+6.28318530717958623*value) + value*(std::log(value)-1.);
}