random_iterator_r123::MicroURNG< CBRNG > Class Template Reference

Given a CBRNG whose ctr_type has an unsigned integral value_type, MicroURNG<CBRNG>(c, k) is a type that satisfies the requirements of a C++11 Uniform Random Number Generator. More...

#include <MicroURNG.hpp>

Public Types
typedef CBRNG	cbrng_type
typedef cbrng_type::ctr_type	ctr_type
typedef cbrng_type::key_type	key_type
typedef cbrng_type::ukey_type	ukey_type
typedef ctr_type::value_type	result_type

Public Member Functions
	RANDOM_ITERATOR_R123_STATIC_ASSERT (std::numeric_limits< result_type >::digits >=BITS, "The result_type must have at least 32 bits")
result_type	operator() ()
	MicroURNG (cbrng_type _b, ctr_type _c0, ukey_type _uk)
	MicroURNG (ctr_type _c0, ukey_type _uk)
const ctr_type &	counter () const
void	reset (ctr_type _c0, ukey_type _uk)

Static Public Attributes
static const int	BITS = 32
static const result_type	_Min = 0
static const result_type	_Max = ~((result_type)0)

Detailed Description

template<typename CBRNG>
class random_iterator_r123::MicroURNG< CBRNG >

Given a CBRNG whose ctr_type has an unsigned integral value_type, MicroURNG<CBRNG>(c, k) is a type that satisfies the requirements of a C++11 Uniform Random Number Generator.

The intended purpose is for a MicroURNG to be passed as an argument to a C++11 Distribution, e.g., std::normal_distribution. See examples/MicroURNG.cpp.

The MicroURNG functor has a period of "only"

ctr_type.size()*2^32,

after which it will silently repeat.

The high 32 bits of the highest word in the counter c, passed to the constructor must be zero. MicroURNG uses these bits to "count".

Older versions of the library permitted a second template parameter by which the caller could control the number of bits devoted to the URNG's internal counter. This flexibility has been disabled because URNGs created with different numbers of counter bits could, conceivably "collide".

typedef ?someCBRNG? RNG;
RNG::ctr_type c = ...; // under application control
RNG::key_type k = ...; //
std::normal_distribution<float> nd;
MicroURNG<RNG> urng(c, k);
for(???){
  ...
  nd(urng);  // may be called several hundred times with BITS=10
  ...
}

Definition at line 79 of file MicroURNG.hpp.

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

• corsika/detail/framework/random/random_iterator/detail/Random123/MicroURNG.hpp