Provided by: libstdc++6-4.4-doc_4.4.7-1ubuntu2_all

#### NAME

```       std::exponential_distribution< _RealType > -

```

#### SYNOPSIS

```   Public Types
typedef _RealType input_type
typedef _RealType result_type

Public Member Functions
exponential_distribution (const result_type &__lambda=result_type(1))
_RealType lambda () const
template<class _UniformRandomNumberGenerator > result_type operator()
(_UniformRandomNumberGenerator &__urng)
void reset ()

Friends
template<typename _RealType1 , typename _CharT , typename _Traits > std::basic_ostream<
_CharT,
_Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const
exponential_distribution< _RealType1 > &__x)"
template<typename _CharT , typename _Traits > std::basic_istream< _CharT,
_Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is,
exponential_distribution &__x)"

```

#### DetailedDescription

```   template<typename _RealType = double>class std::exponential_distribution< _RealType >
An exponential continuous distribution for random numbers.

The formula for the exponential probability mass function is \$ p(x) = bda e^{-bda x} \$.

Mean\$ ac{1}{bda} \$ Median\$ ac{}}bda} \$ Mode\$ zero \$ Range\$[0, infty]\$ Standard Deviation\$
ac{1}{bda} \$ Distribution Statistics

Definition at line 2148 of file tr1_impl/random.

```

#### Constructor&DestructorDocumentation

```   template<typename _RealType  = double> std::exponential_distribution< _RealType
>::exponential_distribution (const result_type &__lambda = result_type(1)) [inline,
explicit] Constructs an exponential distribution with inverse scale parameter \$ bda \$.
Definition at line 2161 of file tr1_impl/random.

```

#### MemberFunctionDocumentation

```   template<typename _RealType  = double> _RealType std::exponential_distribution< _RealType
>::lambda () const [inline] Gets the inverse scale parameter of the distribution.
Definition at line 2171 of file tr1_impl/random.

template<typename _RealType  = double> void std::exponential_distribution< _RealType >::reset
() [inline] Resets the distribution.
Has no effect on exponential distributions.

Definition at line 2180 of file tr1_impl/random.

```

#### FriendsAndRelatedFunctionDocumentation

```   template<typename _RealType  = double> template<typename _RealType1 , typename _CharT ,
typename _Traits > std::basic_ostream<_CharT, _Traits>& operator<< (std::basic_ostream<
_CharT, _Traits > &__os, const exponential_distribution< _RealType1 > &__x) [friend]
Inserts a exponential_distribution random number distribution __x into the output stream
__os.
Parameters:
__os An output stream.
__x A exponential_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 _CharT , typename _Traits >
std::basic_istream<_CharT, _Traits>& operator>> (std::basic_istream< _CharT, _Traits >
&__is, exponential_distribution< _RealType > &__x) [friend] Extracts a
exponential_distribution random number distribution __x from the input stream __is.
Parameters:
__is An input stream.
__x A exponential_distribution random number generator engine.

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

Definition at line 2214 of file tr1_impl/random.

```

#### Author

```       Generated automatically by Doxygen for libstdc++ from the source code.

libstdc++                                Mon Apr std::exponential_distribution< _RealType >(3cxx)
```