std::gamma_distribution

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std::gamma_distribution
Member functions gamma_distribution::gamma_distribution gamma_distribution::reset Generation gamma_distribution::operator() Characteristics gamma_distribution::alpha gamma_distribution::beta gamma_distribution::param gamma_distribution::min gamma_distribution::max Non-member functions operator== operator!= operator<< operator>>

Defined in header <random>
template< class RealType = double > class gamma_distribution;		(since C++11)

Produces random positive integer values x, distributed according to probability density function:

P(x|α,β) =

e-x/β

βα · Γ(α)

where α is known as the shape parameter and β is known as the scale parameter.

For integer α, the value obtained is the sum of α independent exponentially distributed random variables, each of which has a mean of β

Contents 1 Member types 2 Member functions 2.1 Generation 2.2 Characteristics 3 Non-member functions 4 Example 5 External links

[edit] Member types

Member type	Definition
result_type	RealType
param_type	the type of the parameter set, unspecified

[edit] Member functions

(constructor)	constructs new distribution (public member function)
reset	resets the internal state of the distribution (public member function)
Generation
operator()	generates the next random number in the distribution (public member function)
Characteristics
alpha	returns the α distribution parameter (shape) (public member function)
beta	returns the β distribution parameter (scale) (public member function)
param	gets or sets the distribution parameter object (public member function)
min	returns the minimum potentially generated value (public member function)
max	returns the maximum potentially generated value (public member function)

[edit] Non-member functions

operator== operator!=	compares two distribution objects (function)
operator<< operator>>	performs stream input and output on pseudo-random number distribution (function)

[edit] Example

This section is incomplete

[edit] External links

Weisstein, Eric W. "Gamma Distribution." From MathWorld--A Wolfram Web Resource.