# QuantLib_GammaFunction man page

GammaFunction — Gamma function class.

## Synopsis

`#include <ql/math/distributions/gammadistribution.hpp>`

Inherits unary_function< Real, Real >.

### Public Member Functions

Real value(Realx) constReal logValue(Realx) const

## Detailed Description

Gamma function class.

This is a function defined by [ Gamma(z) = int_0^{infty}t^{z-1}e^{-t}dt ]

The implementation of the algorithm was inspired by 'Numerical Recipes in C', 2nd edition, Press, Teukolsky, Vetterling, Flannery, chapter 6

**Tests**

the correctness of the returned value is tested by checking it against known good results.

## Author

Generated automatically by Doxygen for QuantLib from the source code.

## Referenced By

logValue(3) is an alias of QuantLib_GammaFunction(3).

Fri Sep 23 2016 Version 1.8.1 QuantLib