std::tr1::normal_distribution

Langue: en

Autres versions - même langue

Version: 320186 (ubuntu - 07/07/09)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

std::tr1::normal_distribution - A normal continuous distribution for random numbers.

SYNOPSIS


Public Types


typedef _RealType input_type

typedef _RealType result_type

Public Member Functions


_RealType mean () const

normal_distribution (const result_type &__mean=result_type(0), const result_type &__sigma=result_type(1))

template<class _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng)

void reset ()

_RealType sigma () const

Friends


template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const normal_distribution< _RealType1 > &__x)

template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, normal_distribution< _RealType1 > &__x)

Detailed Description

template<typename _RealType = double> class std::tr1::normal_distribution< _RealType >

The formula for the normal probability mass function is $ p(x) = ac{1}{igma qrt{2
i}} e^{- ac{{x - mean}^ {2}}{2 igma ^ {2}} } $.

Definition at line 2196 of file random.

Constructor & Destructor Documentation

template<typename _RealType = double> std::tr1::normal_distribution< _RealType >::normal_distribution (const result_type & __mean = result_type(0), const result_type & __sigma = result_type(1)) [inline, explicit]

Constructs a normal distribution with parameters $ mean $ and $ igma $.

Definition at line 2209 of file random.

Member Function Documentation

template<typename _RealType = double> _RealType std::tr1::normal_distribution< _RealType >::mean () const [inline]

Gets the mean of the distribution.

Definition at line 2220 of file random.

template<typename _RealType > template<class _UniformRandomNumberGenerator > normal_distribution< _RealType >::result_type std::tr1::normal_distribution< _RealType >::operator() (_UniformRandomNumberGenerator & __urng) [inline]

Polar method due to Marsaglia.

Devroye, L. 'Non-Uniform Random Variates Generation.' Springer-Verlag, New York, 1986, Ch. V, Sect. 4.4.

Definition at line 1360 of file random.tcc.

template<typename _RealType = double> void std::tr1::normal_distribution< _RealType >::reset () [inline]

Resets the distribution.

Definition at line 2234 of file random.

template<typename _RealType = double> _RealType std::tr1::normal_distribution< _RealType >::sigma () const [inline]

Gets the $ igma $ of the distribution.

Definition at line 2227 of file random.

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

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

Parameters:

__os An output stream.
__x A normal_distribution random number distribution.

Returns:

The output stream with the state of __x inserted or in an error state.

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

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

Parameters:

__is An input stream.
__x A normal_distribution random number generator engine.

Returns:

The input stream with __x extracted or in an error state.

Author

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