StdRandom< T > Class Template Reference

Inheritance diagram for StdRandom< T >:

Collaboration diagram for StdRandom< T >:

Public Types
using	Engine = std::mt19937
using	result_type = typename RandomBase< T >::result_type
using	uint_type = typename RandomBase< T >::uint_type
Public Types inherited from RandomBase< T >
using	result_type = T
using	uint_type = uint_fast32_t

Public Member Functions
	StdRandom (uint_type iseed=911)
void	init (int iseed_in) override
void	seed (uint_type aseed) override
result_type	operator() () override
void	write (std::ostream &rout) const override
void	read (std::istream &rin) override
size_t	state_size () const override
void	load (const std::vector< uint_type > &newstate) override
void	save (std::vector< uint_type > &curstate) const override
std::unique_ptr< RandomBase< T > >	makeClone () const override
Public Member Functions inherited from RandomBase< T >
virtual	~RandomBase ()=default

Public Attributes
std::string	ClassName {"StdRand"}
std::string	EngineName {"std::mt19937"}

Private Attributes
uniform_real_distribution_as_boost< T >	distribution
	random number generator [0,1) More...
Engine	engine
std::size_t	stream_state_size
	the number count of streaming states. Must match read/write/load/save More...

Detailed Description

template<typename T>
class qmcplusplus::StdRandom< T >

Definition at line 55 of file StdRandom.h.

Member Typedef Documentation

Engine

using Engine = std::mt19937

Definition at line 58 of file StdRandom.h.

result_type

using result_type = typename RandomBase<T>::result_type

Definition at line 59 of file StdRandom.h.

uint_type

using uint_type = typename RandomBase<T>::uint_type

Definition at line 60 of file StdRandom.h.

Constructor & Destructor Documentation

StdRandom()

StdRandom

(

uint_type

iseed = 911

)

Definition at line 17 of file StdRandom.cpp.

                                       : engine(iseed)
{
  static_assert(std::is_same_v<Engine::result_type, uint_type>);
  // Although MT19937 needs only 624 numbers to hold the state, C++ standard libraries may choose different
  // ways to represent the state. libc++ uses 624 numbers but libstdc++ uses 625 numbers. The additional
  // number is an index to the 624 numbers. So we will just count and store the number.
  std::vector<uint_type> state;
  state.reserve(625); // the magic number is chosen based on libstdc++ using 625 numbers while libc++ uses 624
  std::stringstream otemp;
  otemp << engine;
  std::copy(std::istream_iterator<uint_type>(otemp), std::istream_iterator<uint_type>(), std::back_inserter(state));
  stream_state_size = state.size();
}

Member Function Documentation

init()

void init ( int  iseed_in )

inlineoverridevirtual

Implements RandomBase< T >.

Definition at line 64 of file StdRandom.h.

Referenced by qmcplusplus::TEST_CASE().

  {
    uint_type baseSeed = iseed_in;
    engine.seed(baseSeed);
  }

load()

void load ( const std::vector< uint_type > &  newstate )

overridevirtual

Implements RandomBase< T >.

Definition at line 32 of file StdRandom.cpp.

{
  std::stringstream otemp;
  std::copy(newstate.begin(), newstate.end(), std::ostream_iterator<uint_type>(otemp, " "));
  otemp >> engine;
}

makeClone()

std::unique_ptr<RandomBase<T> > makeClone ( ) const

inlineoverridevirtual

Implements RandomBase< T >.

Definition at line 78 of file StdRandom.h.

{ return std::make_unique<StdRandom<T>>(*this); }

operator()()

StdRandom< T >::result_type operator() ( )

overridevirtual

Implements RandomBase< T >.

Definition at line 49 of file StdRandom.cpp.

{
  return distribution(engine);
}

read()

void read ( std::istream &  rin )

inlineoverridevirtual

Implements RandomBase< T >.

Definition at line 73 of file StdRandom.h.

{ rin >> engine; }

save()

void save ( std::vector< uint_type > &  curstate ) const

overridevirtual

Implements RandomBase< T >.

Definition at line 40 of file StdRandom.cpp.

{
  curstate.clear();
  std::stringstream otemp;
  otemp << engine;
  std::copy(std::istream_iterator<uint_type>(otemp), std::istream_iterator<uint_type>(), std::back_inserter(curstate));
}

seed()

void seed ( uint_type  aseed )

inlineoverridevirtual

Implements RandomBase< T >.

Definition at line 70 of file StdRandom.h.

{ engine.seed(aseed); }

state_size()

size_t state_size ( ) const

inlineoverridevirtual

Implements RandomBase< T >.

Definition at line 74 of file StdRandom.h.

{ return stream_state_size; }

write()

void write ( std::ostream &  rout ) const

inlineoverridevirtual

Implements RandomBase< T >.

Definition at line 72 of file StdRandom.h.

{ rout << engine; }

Member Data Documentation

ClassName

std::string ClassName {"StdRand"}

Definition at line 81 of file StdRandom.h.

distribution

uniform_real_distribution_as_boost<T> distribution

private

random number generator [0,1)

Definition at line 86 of file StdRandom.h.

engine

Engine engine

private

Definition at line 87 of file StdRandom.h.

Referenced by StdRandom< RngValueType< T > >::init(), StdRandom< RngValueType< T > >::read(), StdRandom< RngValueType< T > >::seed(), and StdRandom< RngValueType< T > >::write().

EngineName

std::string EngineName {"std::mt19937"}

Definition at line 82 of file StdRandom.h.

stream_state_size

std::size_t stream_state_size

private

the number count of streaming states. Must match read/write/load/save

Definition at line 89 of file StdRandom.h.

Referenced by StdRandom< RngValueType< T > >::state_size().

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

• /home/pk7/projects/qmc/for_cron_doxygen/qmcpack/src/Utilities/StdRandom.h
• /home/pk7/projects/qmc/for_cron_doxygen/qmcpack/src/Utilities/StdRandom.cpp