std::tr1::subtract_with_carry< _IntType, __m, __s, __r > Class Template Reference
[Random Number Generators]

The Marsaglia-Zaman generator. More...

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Public Types

Public Member Functions

Static Public Attributes

Friends


Detailed Description

template<typename _IntType, _IntType __m, int __s, int __r>
class std::tr1::subtract_with_carry< _IntType, __m, __s, __r >

This is a model of a Generalized Fibonacci discrete random number generator, sometimes referred to as the SWC generator.

A discrete random number generator that produces pseudorandom numbers using $x_{i}\leftarrow(x_{i - s} - x_{i - r} - carry_{i-1}) \bmod m $.

The size of the state is $ r $ and the maximum period of the generator is $ m^r - m^s -1 $.

N1688[4.13] says "the template parameter _IntType shall denote an integral type large enough to store values up to m."

Definition at line 668 of file random.


Member Typedef Documentation

template<typename _IntType, _IntType __m, int __s, int __r>
typedef _IntType std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::result_type

The type of the generated random value.

Definition at line 674 of file random.


Constructor & Destructor Documentation

template<typename _IntType, _IntType __m, int __s, int __r>
std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::subtract_with_carry (  )  [inline]

Constructs a default-initialized % subtract_with_carry random number generator.

Definition at line 685 of file random.

template<typename _IntType, _IntType __m, int __s, int __r>
std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::subtract_with_carry ( unsigned long  __value  )  [inline, explicit]

Constructs an explicitly seeded % subtract_with_carry random number generator.

Definition at line 693 of file random.

template<typename _IntType, _IntType __m, int __s, int __r>
template<class _Gen >
std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::subtract_with_carry ( _Gen &  __g  )  [inline]

Constructs a subtract_with_carry random number generator engine seeded from the generator function __g.

Parameters:
__g The seed generator function.

Definition at line 703 of file random.


Member Function Documentation

template<typename _IntType, _IntType __m, int __s, int __r>
result_type std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::max (  )  const [inline]

Gets the inclusive maximum value of the range of random integers returned by this generator.

Definition at line 742 of file random.

template<typename _IntType, _IntType __m, int __s, int __r>
result_type std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::min (  )  const [inline]

Gets the inclusive minimum value of the range of random integers returned by this generator.

Definition at line 734 of file random.

template<typename _IntType , _IntType __m, int __s, int __r>
subtract_with_carry< _IntType, __m, __s, __r >::result_type std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::operator() (  )  [inline]

Gets the next random number in the sequence.

Definition at line 362 of file random.tcc.

template<typename _IntType, _IntType __m, int __s, int __r>
template<class _Gen >
void std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::seed ( _Gen &  __g  )  [inline]

Seeds the initial state $ x_0 $ of the % subtract_with_carry random number generator.

Definition at line 726 of file random.

References std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::seed().

Referenced by std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::seed().

template<typename _IntType , _IntType __m, int __s, int __r>
void std::tr1::subtract_with_carry< _IntType, __m, __s, __r >::seed ( unsigned long  __value = 19780503  )  [inline]

Seeds the initial state $ x_0 $ of the random number generator.

N1688[4.19] modifies this as follows. If __value == 0, sets value to 19780503. In any case, with a linear congruential generator lcg(i) having parameters $ m_{lcg} = 2147483563, a_{lcg} = 40014, c_{lcg} = 0, and lcg(0) = value $, sets $ x_{-r} \dots x_{-1} $ to $ lcg(1) \bmod m \dots lcg(r) \bmod m $ respectively. If $ x_{-1} = 0 $ set carry to 1, otherwise sets carry to 0.

Definition at line 320 of file random.tcc.


Friends And Related Function Documentation

template<typename _IntType, _IntType __m, int __s, int __r>
bool operator!= ( const subtract_with_carry< _IntType, __m, __s, __r > &  __lhs,
const subtract_with_carry< _IntType, __m, __s, __r > &  __rhs 
) [friend]

Compares two % subtract_with_carry random number generator objects of the same type for inequality.

Parameters:
__lhs A % subtract_with_carry random number generator object.
__rhs Another % subtract_with_carry random number generator object.
Returns:
true if the two objects are not equal, false otherwise.

Definition at line 777 of file random.

template<typename _IntType, _IntType __m, int __s, int __r>
template<typename _IntType1 , _IntType1 __m1, int __s1, int __r1, typename _CharT , typename _Traits >
std::basic_ostream<_CharT, _Traits>& operator<< ( std::basic_ostream< _CharT, _Traits > &  __os,
const subtract_with_carry< _IntType1, __m1, __s1, __r1 > &  __x 
) [friend]

Inserts the current state of a % subtract_with_carry random number generator engine __x into the output stream __os.

Parameters:
__os An output stream.
__x A % subtract_with_carry random number generator engine.
Returns:
The output stream with the state of __x inserted or in an error state.

template<typename _IntType, _IntType __m, int __s, int __r>
bool operator== ( const subtract_with_carry< _IntType, __m, __s, __r > &  __lhs,
const subtract_with_carry< _IntType, __m, __s, __r > &  __rhs 
) [friend]

Compares two % subtract_with_carry random number generator objects of the same type for equality.

Parameters:
__lhs A % subtract_with_carry random number generator object.
__rhs Another % subtract_with_carry random number generator object.
Returns:
true if the two objects are equal, false otherwise.

Definition at line 762 of file random.

template<typename _IntType, _IntType __m, int __s, int __r>
template<typename _IntType1 , _IntType1 __m1, int __s1, int __r1, typename _CharT , typename _Traits >
std::basic_istream<_CharT, _Traits>& operator>> ( std::basic_istream< _CharT, _Traits > &  __is,
subtract_with_carry< _IntType1, __m1, __s1, __r1 > &  __x 
) [friend]

Extracts the current state of a % subtract_with_carry random number generator engine __x from the input stream __is.

Parameters:
__is An input stream.
__x A % subtract_with_carry random number generator engine.
Returns:
The input stream with the state of __x extracted or in an error state.


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

Generated on Sat Jan 10 19:12:04 2009 for libstdc++ by  doxygen 1.5.8