Classes¶

struct param_type

Public Types¶

typedef _RealType result_type

Public Member Functions¶

gamma_distribution ()
Constructs a gamma distribution with parameters 1 and 1. gamma_distribution (_RealType __alpha_val, _RealType __beta_val=_RealType(1))
Constructs a gamma distribution with parameters $ lpha$ and $ gamma_distribution (const param_type &__p)
template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void __generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng)
template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void __generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng, const param_type &__p)
template<typename _UniformRandomNumberGenerator > void __generate (result_type *__f, result_type *__t, _UniformRandomNumberGenerator &__urng, const param_type &__p)
_RealType alpha () const
Returns the $ lpha$ of the distribution. _RealType beta () const
Returns the $ distribution. result_type max () const
Returns the least upper bound value of the distribution. result_type min () const
Returns the greatest lower bound value of the distribution. template<typename _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng)
Generating functions. template<typename _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng, const param_type &__p)
param_type param () const
Returns the parameter set of the distribution. void param (const param_type &__param)
Sets the parameter set of the distribution. void reset ()
Resets the distribution state.

Friends¶

template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const std::gamma_distribution< _RealType1 > &__x)
Inserts a gamma_distribution random number distribution __x into the output stream __os. bool operator== (const gamma_distribution &__d1, const gamma_distribution &__d2)
Return true if two gamma distributions have the same parameters and the sequences that would be generated are equal. template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, std::gamma_distribution< _RealType1 > &__x)
Extracts a gamma_distribution random number distribution __x from the input stream __is.

template<typename _RealType = double>¶

class std::gamma_distribution< _RealType >"A gamma continuous distribution for random numbers.

The formula for the gamma probability density function is:
p(x|lpha,ac{1}{
(x/^{-x/ ]

Definition at line 2407 of file random.

template<typename _RealType = double> typedef _RealType std::gamma_distribution< _RealType >::result_type¶

The type of the range of the distribution.

Definition at line 2414 of file random.

template<typename _RealType = double> std::gamma_distribution< _RealType >::gamma_distribution () [inline]¶

Constructs a gamma distribution with parameters 1 and 1.

Definition at line 2463 of file random.

template<typename _RealType = double> std::gamma_distribution< _RealType >::gamma_distribution (_RealType __alpha_val, _RealType __beta_val = _RealType(1)) [inline], [explicit]¶

Constructs a gamma distribution with parameters $lpha$ and $

Definition at line 2470 of file random.

template<typename _RealType = double> std::gamma_distribution< _RealType >::gamma_distribution (const param_type & __p) [inline], [explicit]¶

Definition at line 2476 of file random.

template<typename _RealType = double> template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void std::gamma_distribution< _RealType >::__generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator & __urng) [inline]¶

Definition at line 2546 of file random.

template<typename _RealType = double> template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void std::gamma_distribution< _RealType >::__generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator & __urng, const param_type & __p) [inline]¶

Definition at line 2553 of file random.

template<typename _RealType = double> template<typename _UniformRandomNumberGenerator > void std::gamma_distribution< _RealType >::__generate (result_type * __f, result_type * __t, _UniformRandomNumberGenerator & __urng, const param_type & __p) [inline]¶

Definition at line 2560 of file random.

template<typename _RealType = double> _RealType std::gamma_distribution< _RealType >::alpha () const [inline]¶

Returns the $lpha$ of the distribution.

Definition at line 2491 of file random.

template<typename _RealType = double> _RealType std::gamma_distribution< _RealType >::beta () const [inline]¶

Returns the $ distribution.

Definition at line 2498 of file random.

template<typename _RealType = double> result_type std::gamma_distribution< _RealType >::max () const [inline]¶

Returns the least upper bound value of the distribution.

Definition at line 2527 of file random.

References std::numeric_limits< _Tp >::max().

template<typename _RealType = double> result_type std::gamma_distribution< _RealType >::min () const [inline]¶

Returns the greatest lower bound value of the distribution.

Definition at line 2520 of file random.

template<typename _RealType = double> template<typename _UniformRandomNumberGenerator > result_type std::gamma_distribution< _RealType >::operator() (_UniformRandomNumberGenerator & __urng) [inline]¶

Generating functions.

Definition at line 2535 of file random.

References std::gamma_distribution< _RealType >::operator()().

Referenced by std::gamma_distribution< _RealType >::operator()().

template<typename _RealType > template<typename _UniformRandomNumberGenerator > gamma_distribution< _RealType >::result_type std::gamma_distribution< _RealType >::operator() (_UniformRandomNumberGenerator & __urng, const param_type & __param)¶

Marsaglia, G. and Tsang, W. W. 'A Simple Method for Generating Gamma Variables' ACM Transactions on Mathematical Software, 26, 3, 363-372, 2000.

Definition at line 2360 of file bits/random.tcc.

References std::log(), and std::pow().

template<typename _RealType = double> param_type std::gamma_distribution< _RealType >::param () const [inline]¶

Returns the parameter set of the distribution.

Definition at line 2505 of file random.

Referenced by std::chi_squared_distribution< _RealType >::param().

template<typename _RealType = double> void std::gamma_distribution< _RealType >::param (const param_type & __param) [inline]¶

Sets the parameter set of the distribution.

Parameters

Definition at line 2513 of file random.

template<typename _RealType = double> void std::gamma_distribution< _RealType >::reset () [inline]¶

Resets the distribution state.

Definition at line 2484 of file random.

References std::normal_distribution< _RealType >::reset().

Referenced by std::chi_squared_distribution< _RealType >::reset(), std::fisher_f_distribution< _RealType >::reset(), std::student_t_distribution< _RealType >::reset(), and std::negative_binomial_distribution< _IntType >::reset().

template<typename _RealType = double> template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > & __os, const std::gamma_distribution< _RealType1 > & __x) [friend]¶

Inserts a gamma_distribution random number distribution __x into the output stream __os.

Parameters

Returns

template<typename _RealType = double> bool operator== (const gamma_distribution< _RealType > & __d1, const gamma_distribution< _RealType > & __d2) [friend]¶

Return true if two gamma distributions have the same parameters and the sequences that would be generated are equal.

Definition at line 2571 of file random.

template<typename _RealType = double> template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > & __is, std::gamma_distribution< _RealType1 > & __x) [friend]¶

Extracts a gamma_distribution random number distribution __x from the input stream __is.

Parameters

Returns