Zipf Distributed Random VariableZipfVariable defines a discrete random variable with Zipf distribution. More...

#include <random-variable.h>

Inheritance diagram for ns3::ZipfVariable:

Collaboration diagram for ns3::ZipfVariable:

Public Member Functions
	ZipfVariable (long N, double alpha)
	Returns a Zipf random variable with parameters N and alpha.
	ZipfVariable ()
Public Member Functions inherited from ns3::RandomVariable
	RandomVariable ()
	RandomVariable (const RandomVariable &o)
	~RandomVariable ()
uint32_t	GetInteger (void) const
	Returns a random integer integer from the underlying distribution.
double	GetValue (void) const
	Returns a random double from the underlying distribution.
RandomVariable &	operator= (const RandomVariable &o)

Additional Inherited Members
Protected Member Functions inherited from ns3::RandomVariable
	RandomVariable (const RandomVariableBase &variable)
RandomVariableBase *	Peek (void) const

Detailed Description

Zipf Distributed Random Variable

ZipfVariable defines a discrete random variable with Zipf distribution.

The Zipf's law states that given some corpus of natural language utterances, the frequency of any word is inversely proportional to its rank in the frequency table.

Zipf's distribution have two parameters, alpha and N, where: $\alpha > 0$ (real) and $N \in \{1,2,3 \dots\}$ (integer). Probability Mass Function is $f(k; \alpha, N) = k^{-\alpha}/ H_{N,\alpha}$ where $H_{N,\alpha} = \sum_{n=1}^N n^{-\alpha}$