ZipfDistribution Class Reference

Detailed Description

A class for producing random integers distributed according to the Zipf-Mandelbrot probability mass function:

p(k;N,q,s) = 1/( H(N,q,s)*(k+q)^s )

where H(N,q,s) = sum_(n=1)^(N) 1/(n+q)^s

and s > 1, q >= 0, N > 1.

When q = 0 this becomes the mass function for Zipf's Law When N -> infinity this becomes the Hurwitz Zeta mass function When N -> infinity and q = 0, this becomes the Riemann Zeta mass function

Definition at line 70 of file zipf_distribution.hpp.

#include <zipf_distribution.hpp>

Public Member Functions
	ZipfDistribution ()=default
	create uninitialized object. be careful. More...
	ZipfDistribution (const size_t N, const double s, const double q=0)
	Creates a new Zipf-Mandelbrot distribution given s, q, N. More...
size_t	max () const
	maximum value (inclusive) of distribution More...
size_t	min () const
	minimum value of distribution More...
size_t	N () const
	deliver population size More...
template<typename Engine >
size_t	operator() (Engine &eng)
	pick next random number in the range [1,num) More...
double	q () const
	parameter of distribution More...
double	s () const
	parameter of distribution More...

Private Types
using	dist_type = std::discrete_distribution< size_t >

Static Private Member Functions
static dist_type	make_dist (size_t N, double s, double q)

Private Attributes
dist_type	dist_
size_t	N_
double	q_
double	s_

Member Typedef Documentation

dist_type

using dist_type = std::discrete_distribution<size_t>

private

Definition at line 116 of file zipf_distribution.hpp.

Constructor & Destructor Documentation

ZipfDistribution() [1/2]

ZipfDistribution ( )

default

create uninitialized object. be careful.

ZipfDistribution() [2/2]

ZipfDistribution ( const size_t  N, const double  s, const double  q = 0  )

inline

Creates a new Zipf-Mandelbrot distribution given s, q, N.

p(k;N,q,s) = 1/( H(N,q,s)*(k+q)^s )

where H(N,q,s) = sum_(n=1)^(N) 1/(n+q)^s

and s > 1, q >= 0, N > 1

Only N and s needs to be specified. The default for q is 0.

Definition at line 88 of file zipf_distribution.hpp.

Member Function Documentation

make_dist()

static dist_type make_dist ( size_t  N, double  s, double  q  )

inlinestaticprivate

Definition at line 119 of file zipf_distribution.hpp.

References LOG1, and ZipfDistribution::N().

max()

size_t max ( ) const

inline

maximum value (inclusive) of distribution

Definition at line 109 of file zipf_distribution.hpp.

References ZipfDistribution::N_.

min()

size_t min ( ) const

inline

minimum value of distribution

Definition at line 106 of file zipf_distribution.hpp.

N()

size_t N ( ) const

inline

deliver population size

Definition at line 97 of file zipf_distribution.hpp.

References ZipfDistribution::N_.

Referenced by ZipfDistribution::make_dist().

operator()()

size_t operator() ( Engine &  eng )

inline

pick next random number in the range [1,num)

Definition at line 94 of file zipf_distribution.hpp.

References ZipfDistribution::dist_.

q()

double q ( ) const

inline

parameter of distribution

Definition at line 100 of file zipf_distribution.hpp.

References ZipfDistribution::q_.

s()

double s ( ) const

inline

parameter of distribution

Definition at line 103 of file zipf_distribution.hpp.

References ZipfDistribution::s_.

Member Data Documentation

dist_

dist_type dist_

private

Definition at line 117 of file zipf_distribution.hpp.

Referenced by ZipfDistribution::operator()().

N_

size_t N_

private

Definition at line 112 of file zipf_distribution.hpp.

Referenced by ZipfDistribution::max(), and ZipfDistribution::N().

q_

double q_

private

Definition at line 114 of file zipf_distribution.hpp.

Referenced by ZipfDistribution::q().

s_

double s_

private

Definition at line 113 of file zipf_distribution.hpp.

Referenced by ZipfDistribution::s().

---

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

• thrill/common/zipf_distribution.hpp