libstdc++
std::normal_distribution< _RealType > Class Template Reference

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::normal_distribution< _RealType >

A normal continuous distribution for random numbers.

The formula for the normal probability mass function is $ p(x) = \frac{1}{\sigma \sqrt{2 \pi}} e^{- \frac{{x - mean}^ {2}}{2 \sigma ^ {2}} } $.

Definition at line 2231 of file tr1_impl/random.

Constructor & Destructor Documentation

template<typename _RealType = double>
std::normal_distribution< _RealType >::normal_distribution ( const result_type &  __mean = result_type(0),
const result_type &  __sigma = result_type(1) 
)
inlineexplicit

Constructs a normal distribution with parameters $ mean $ and $ \sigma $.

Definition at line 2244 of file tr1_impl/random.

Member Function Documentation

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

Gets the mean of the distribution.

Definition at line 2255 of file tr1_impl/random.

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

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 1390 of file random.tcc.

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

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

Resets the distribution.

Definition at line 2269 of file tr1_impl/random.

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

Gets the $ \sigma $ of the distribution.

Definition at line 2262 of file tr1_impl/random.

Friends And Related Function Documentation

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
__osAn output stream.
__xA 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
__isAn input stream.
__xA normal_distribution random number generator engine.
Returns
The input stream with __x extracted or in an error state.

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