ExRandom: exrandom::discrete_normal_distribution Class Reference

ExRandom 3.0

Sample exactly from the discrete normal distribution. More...

#include <exrandom/discrete_normal_distribution.hpp>

Classes
struct	param_type
	Parameter type for discrete_normal_distribution. More...

Public Types
typedef int	result_type

Public Member Functions
	discrete_normal_distribution ()

	discrete_normal_distribution (const param_type &p)

	discrete_normal_distribution (int mu, int sigma)

	discrete_normal_distribution (int mu_num, int sigma_num, int den)

	discrete_normal_distribution (int mu_num, int mu_den, int sigma_num, int sigma_den)

void	reset ()

result_type	mu_num () const

result_type	mu_den () const

result_type	sigma_num () const

result_type	sigma_den () const

param_type	param () const

void	param (const param_type &param)

result_type	min () const

result_type	max () const

template<typename Generator >
result_type	operator() (Generator &g)

template<typename Generator >
result_type	operator() (Generator &g, const param_type &p)

Friends
bool	operator== (const discrete_normal_distribution &d1, const discrete_normal_distribution &d2)

bool	operator!= (const discrete_normal_distribution &d1, const discrete_normal_distribution &d2)

std::ostream &	operator<< (std::ostream &os, const discrete_normal_distribution &x)

std::istream &	operator>> (std::istream &is, discrete_normal_distribution &x)

Detailed Description

Sample exactly from the discrete normal distribution.

This samples from the discrete normal distribution P_i ∝ exp[− ((i − μ)/σ)²/2], where μ and σ > 0 are specified as rational numbers (the ratio of two ints). This implements Algorithm D with improvements due to Du et al. (2020).

This is a wrapper for discrete_normal_dist to turn it into a C++11 style random distribution. The base for discrete_normal_dist is set to 2¹⁶.

Examples: chisq_test.cpp, compare_times.cpp, exrandom_test.cpp, sample_distributions.cpp, and simple_discrete_normal.cpp.

Definition at line 33 of file discrete_normal_distribution.hpp.

Member Typedef Documentation

◆ result_type

typedef int exrandom::discrete_normal_distribution::result_type

The type of the range of the distribution.

Definition at line 40 of file discrete_normal_distribution.hpp.

Constructor & Destructor Documentation

◆ discrete_normal_distribution() [1/5]

exrandom::discrete_normal_distribution::discrete_normal_distribution ( )

inlineexplicit

The default constructor.

Sets μ = 0 and σ = 1

Definition at line 102 of file discrete_normal_distribution.hpp.

◆ discrete_normal_distribution() [2/5]

exrandom::discrete_normal_distribution::discrete_normal_distribution ( const param_type & p )

inlineexplicit

Construct from a param_type.

Parameters

p

Definition at line 109 of file discrete_normal_distribution.hpp.

◆ discrete_normal_distribution() [3/5]

exrandom::discrete_normal_distribution::discrete_normal_distribution	(	int	mu,
		int	sigma
	)

inlineexplicit

Construct with integer parameters.

Parameters

mu	the value of μ.
sigma	the value of σ.

Sets μ = mu and σ = sigma.

Definition at line 120 of file discrete_normal_distribution.hpp.

◆ discrete_normal_distribution() [4/5]

exrandom::discrete_normal_distribution::discrete_normal_distribution	(	int	mu_num,
		int	sigma_num,
		int	den
	)

inlineexplicit

Construct with parameters with a common denominator.

Parameters

mu_num	the numerator of μ.
sigma_num	the numerator of σ.
den	the common denominator.

Sets μ = mu_num / den and σ = sigma_num / den.

Definition at line 134 of file discrete_normal_distribution.hpp.

◆ discrete_normal_distribution() [5/5]

exrandom::discrete_normal_distribution::discrete_normal_distribution	(	int	mu_num,
		int	mu_den,
		int	sigma_num,
		int	sigma_den
	)

inlineexplicit

Construct from the individual parameters.

Parameters

mu_num	the numerator of μ.
mu_den	the denominator of μ.
sigma_num	the numerator of σ.
sigma_den	the denominator of σ.

Sets μ = mu_num / mu_den and σ = sigma_num / sigma_den.

Definition at line 149 of file discrete_normal_distribution.hpp.

Member Function Documentation

◆ reset()

void exrandom::discrete_normal_distribution::reset ( )

inline

Resets the distribution state.

Definition at line 157 of file discrete_normal_distribution.hpp.

◆ mu_num()

result_type exrandom::discrete_normal_distribution::mu_num ( ) const

inline

Returns: the numerator of μ.

Examples: simple_discrete_normal.cpp.

Definition at line 162 of file discrete_normal_distribution.hpp.

◆ mu_den()

result_type exrandom::discrete_normal_distribution::mu_den ( ) const

inline

Returns: the denominator of μ.

Examples: simple_discrete_normal.cpp.

Definition at line 166 of file discrete_normal_distribution.hpp.

◆ sigma_num()

result_type exrandom::discrete_normal_distribution::sigma_num ( ) const

inline

Returns: the numerator of σ.

Examples: simple_discrete_normal.cpp.

Definition at line 170 of file discrete_normal_distribution.hpp.

◆ sigma_den()

result_type exrandom::discrete_normal_distribution::sigma_den ( ) const

inline

Returns: the denominator of σ.

Examples: simple_discrete_normal.cpp.

Definition at line 174 of file discrete_normal_distribution.hpp.

◆ param() [1/2]

param_type exrandom::discrete_normal_distribution::param ( ) const

inline

Returns: the parameter set of the distribution.

Definition at line 179 of file discrete_normal_distribution.hpp.

◆ param() [2/2]

void exrandom::discrete_normal_distribution::param ( const param_type & param )

inline

Sets the parameter set of the distribution.

Parameters

param The new parameter set of the distribution.

Definition at line 185 of file discrete_normal_distribution.hpp.

◆ min()

result_type exrandom::discrete_normal_distribution::min ( ) const

inline

Returns: the greatest lower bound value of the distribution.

Definition at line 191 of file discrete_normal_distribution.hpp.

◆ max()

result_type exrandom::discrete_normal_distribution::max ( ) const

inline

Returns: the least upper bound value of the distribution.

Definition at line 197 of file discrete_normal_distribution.hpp.

◆ operator()() [1/2]

template<typename Generator >

result_type exrandom::discrete_normal_distribution::operator() ( Generator & g )

inline

Template Parameters

Generator the type of g.

Parameters

g	the random generator engine.

Returns: a discrete normal deviate.

Definition at line 206 of file discrete_normal_distribution.hpp.

◆ operator()() [2/2]

template<typename Generator >

result_type exrandom::discrete_normal_distribution::operator()	(	Generator &	g,
		const param_type &	p
	)

inline

Template Parameters

Generator the type of g.

Parameters

g	the random generator engine.
p	a parameter set.

Returns: a discrete normal deviate using the specified parameters.

Definition at line 216 of file discrete_normal_distribution.hpp.

Friends And Related Function Documentation

◆ operator==

bool operator==	(	const discrete_normal_distribution &	d1,
		const discrete_normal_distribution &	d2
	)

friend

Returns: true if two normal distributions have the same parameters.

Definition at line 225 of file discrete_normal_distribution.hpp.

◆ operator!=

bool operator!=	(	const discrete_normal_distribution &	d1,
		const discrete_normal_distribution &	d2
	)

friend

Returns: false if two normal distributions have the same parameters.

Definition at line 233 of file discrete_normal_distribution.hpp.

◆ operator<<

std::ostream& operator<<	(	std::ostream &	os,
		const discrete_normal_distribution &	x
	)

friend

Inserts a discrete_normal_distribution random number distribution x into the output stream os.

Parameters

os	an output stream.
x	a discrete_normal_distribution random number distribution.

Returns: os.

Definition at line 246 of file discrete_normal_distribution.hpp.

◆ operator>>

std::istream& operator>>	(	std::istream &	is,
		discrete_normal_distribution &	x
	)

friend

Extracts a discrete_normal_distribution random number distribution x from the input stream is.

Parameters

is	an input stream.
x	a discrete_normal_distribution random number generator engine.

Returns: is.

Definition at line 258 of file discrete_normal_distribution.hpp.

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

discrete_normal_distribution.hpp