This implements the the Mersenne Twister 19937 pseudo-random number generator algorithm as a specialzation of the PseudoRandomNumberGenerator interface. More...

#include <MersenneTwister.h>

Inheritance diagram for Mantid::Kernel::MersenneTwister:

Public Member Functions
double	max () const override
	Return the maximum value of the range. More...

	MersenneTwister ()
	Construct the generator using time stamp for the initial seed. More...

	MersenneTwister (const double start, const double end)
	Construct the generator with an initial range and default seed. More...

	MersenneTwister (const MersenneTwister &)=delete

	MersenneTwister (const size_t seedValue)
	Construct the generator with an initial seed. More...

	MersenneTwister (const size_t seedValue, const double start, const double end)
	Construct the generator with an initial seed and range. More...

double	min () const override
	Return the minimum value of the range. More...

int	nextInt (int start, int end) override
	Return the next integer in the sequence within the given range. More...

double	nextValue () override
	Generate the next random number in the sequence within the given range default range. More...

double	nextValue (double start, double end) override
	Generate the next random number in the sequence within the given range. More...

MersenneTwister &	operator= (const MersenneTwister &)=delete

void	restart () override
	Resets the generator. More...

void	restore () override
	Restores the generator to the last saved point, or the beginning if nothing has been saved. More...

void	save () override
	Saves the current state of the generator. More...

void	setRange (const double start, const double end) override
	Sets the range of the subsequent calls to next. More...

void	setSeed (const size_t seedValue) override
	Set the random number seed. More...

Public Member Functions inherited from Mantid::Kernel::PseudoRandomNumberGenerator
void	generateNextPoint () override
	Generates the next point. More...

virtual double	max () const =0
	Return the maximum value of the range. More...

virtual double	min () const =0
	Return the minimum value of the range. More...

virtual int	nextInt (int start, int end)=0
	Return the next integer in the sequence. More...

virtual double	nextValue ()=0
	Return the next double in the sequence. More...

virtual double	nextValue (double start, double end)=0
	Return the next double in the sequence overriding the default range. More...

double	operator() ()
	Return next random value. More...

PseudoRandomNumberGenerator &	operator= (const PseudoRandomNumberGenerator &)=delete
	Disable assignment operator. More...

	PseudoRandomNumberGenerator ()
	Default constructor setting the dimension to 1. More...

	PseudoRandomNumberGenerator (const PseudoRandomNumberGenerator &)=delete
	Disable copy operator. More...

virtual void	setRange (const double start, const double end)=0
	Sets the range of the subsequent calls to nextValue;. More...

virtual void	setSeed (const size_t seedValue)=0
	Set the random number seed. More...

Public Member Functions inherited from Mantid::Kernel::NDRandomNumberGenerator
	NDRandomNumberGenerator ()=delete
	Disable default constructor. More...

	NDRandomNumberGenerator (const NDRandomNumberGenerator &)=delete
	Disable copy operator. More...

	NDRandomNumberGenerator (const unsigned int ndims)
	Constructor. More...

const std::vector< double > &	nextPoint ()
	Generate the next set of values that form a point in ND space. More...

unsigned int	numberOfDimensions () const
	Returns the number of dimensions the point will be generated in, i.e. More...

NDRandomNumberGenerator &	operator= (const NDRandomNumberGenerator &)=delete
	Disable assignment operator. More...

virtual void	restart ()=0
	Restarts the generator from the beginning of the sequence. More...

virtual void	restore ()=0
	Restores the generator to the last saved point, or the beginning if nothing has been saved. More...

virtual void	save ()=0
	Saves the current state of the generator. More...

virtual	~NDRandomNumberGenerator ()=default
	Virtual destructor to ensure that all inheriting classes have one. More...

Private Attributes
double	m_end
	Maximum in range. More...

std::mt19937	m_engine
	The engine. More...

std::unique_ptr< std::mt19937 >	m_savedEngine
	A generator that will take the value when save is requested. More...

std::mt19937::result_type	m_seed
	The current seed. More...

double	m_start
	Minimum in range. More...

std::uniform_real_distribution< double >	uniformRealDistribution
	Uniform Real distribution. More...

Additional Inherited Members
Public Types inherited from Mantid::Kernel::PseudoRandomNumberGenerator
using	result_type = double
	Result (output) value type. More...

Protected Member Functions inherited from Mantid::Kernel::NDRandomNumberGenerator
void	cacheGeneratedValue (const size_t index, const double value)
	Cache a value for a given dimension index, i.e. 0->ND-1. More...

void	cacheNextPoint (const std::vector< double > &nextPoint)
	Cache the while point in one go. More...

virtual void	generateNextPoint ()=0
	Generate the next point. Override this in you concrete implementation. More...

std::vector< double > &	getNextPointCache ()
	Some generators need direct access to the cache. More...

Detailed Description

This implements the the Mersenne Twister 19937 pseudo-random number generator algorithm as a specialzation of the PseudoRandomNumberGenerator interface.

Definition at line 24 of file MersenneTwister.h.

Constructor & Destructor Documentation

◆ MersenneTwister() [1/5]

Mantid::Kernel::MersenneTwister::MersenneTwister ( )

Construct the generator using time stamp for the initial seed.

Construct the generator time stamp for the initial seed.

The range is set to [0.0, 1.0]

Definition at line 32 of file MersenneTwister.cpp.

◆ MersenneTwister() [2/5]

Mantid::Kernel::MersenneTwister::MersenneTwister	(	const double	start,
		const double	end
	)

Construct the generator with an initial range and default seed.

Constructor taking a range.

Parameters

start	:: The minimum value a generated number should take
end	:: The maximum value a generated number should take

Definition at line 39 of file MersenneTwister.cpp.

◆ MersenneTwister() [3/5]

Mantid::Kernel::MersenneTwister::MersenneTwister ( const size_t seedValue )

explicit

Construct the generator with an initial seed.

Constructor taking a seed value.

It can be reseeded using setSeed.

Sets the range to [0.0,1.0]

Parameters

seedValue :: The initial seed

Definition at line 26 of file MersenneTwister.cpp.

◆ MersenneTwister() [4/5]

Mantid::Kernel::MersenneTwister::MersenneTwister	(	const size_t	seedValue,
		const double	start,
		const double	end
	)

Construct the generator with an initial seed and range.

Constructor taking a seed value and a range.

Parameters

seedValue	:: The initial seed
start	:: The minimum value a generated number should take
end	:: The maximum value a generated number should take

Definition at line 48 of file MersenneTwister.cpp.

References setSeed().

◆ MersenneTwister() [5/5]

Mantid::Kernel::MersenneTwister::MersenneTwister ( const MersenneTwister & )

delete

Member Function Documentation

◆ max()

double Mantid::Kernel::MersenneTwister::max ( ) const

inlineoverridevirtual

Return the maximum value of the range.

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 63 of file MersenneTwister.h.

◆ min()

double Mantid::Kernel::MersenneTwister::min ( ) const

inlineoverridevirtual

Return the minimum value of the range.

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 61 of file MersenneTwister.h.

◆ nextInt()

int Mantid::Kernel::MersenneTwister::nextInt	(	int	start,
		int	end
	)

overridevirtual

Return the next integer in the sequence within the given range.

Returns the next integer in the pseudo-random sequence generated by the Mersenne Twister 19937 algorithm.

Parameters

start	Start of the requested range
end	End of the requested range

Returns: An integer in the defined range

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 81 of file MersenneTwister.cpp.

References m_engine.

◆ nextValue() [1/2]

double Mantid::Kernel::MersenneTwister::nextValue ( )

inlineoverridevirtual

Generate the next random number in the sequence within the given range default range.

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 46 of file MersenneTwister.h.

Referenced by WorkspaceCreationHelper::addNoise(), WorkspaceCreationHelper::create1DWorkspaceRand(), WorkspaceCreationHelper::createRandomEventWorkspace(), and Mantid::Kernel::Matrix< T >::setRandom().

◆ nextValue() [2/2]

double Mantid::Kernel::MersenneTwister::nextValue	(	double	start,
		double	end
	)

inlineoverridevirtual

Generate the next random number in the sequence within the given range.

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 48 of file MersenneTwister.h.

◆ operator=()

MersenneTwister & Mantid::Kernel::MersenneTwister::operator= ( const MersenneTwister & )

delete

◆ restart()

void Mantid::Kernel::MersenneTwister::restart ( )

overridevirtual

Resets the generator.

Resets the generator using the value given at the last call to setSeed.

Implements Mantid::Kernel::NDRandomNumberGenerator.

Definition at line 88 of file MersenneTwister.cpp.

References m_seed, and setSeed().

Referenced by restore().

◆ restore()

void Mantid::Kernel::MersenneTwister::restore ( )

overridevirtual

Restores the generator to the last saved point, or the beginning if nothing has been saved.

Implements Mantid::Kernel::NDRandomNumberGenerator.

Definition at line 95 of file MersenneTwister.cpp.

References m_engine, m_savedEngine, and restart().

◆ save()

void Mantid::Kernel::MersenneTwister::save ( )

overridevirtual

Saves the current state of the generator.

Implements Mantid::Kernel::NDRandomNumberGenerator.

Definition at line 91 of file MersenneTwister.cpp.

References m_engine, and m_savedEngine.

◆ setRange()

void Mantid::Kernel::MersenneTwister::setRange	(	const double	start,
		const double	end
	)

overridevirtual

Sets the range of the subsequent calls to next.

Sets the range of the subsequent calls to nextValue()

Parameters

start	:: The lowest value a call to nextValue() will produce
end	:: The largest value a call to nextValue() will produce

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 68 of file MersenneTwister.cpp.

References m_end, m_start, and uniformRealDistribution.

◆ setSeed()

void Mantid::Kernel::MersenneTwister::setSeed ( const size_t seedValue )

overridevirtual

Set the random number seed.

(Re-)seed the generator.

This resets the current saved state

Parameters

seedValue :: A seed for the generator

Implements Mantid::Kernel::PseudoRandomNumberGenerator.

Definition at line 57 of file MersenneTwister.cpp.

References m_engine, m_savedEngine, and m_seed.

Referenced by MersenneTwister(), and restart().

Member Data Documentation

◆ m_end

double Mantid::Kernel::MersenneTwister::m_end

private

Maximum in range.

Definition at line 73 of file MersenneTwister.h.

Referenced by setRange().

◆ m_engine

std::mt19937 Mantid::Kernel::MersenneTwister::m_engine

private

The engine.

Definition at line 67 of file MersenneTwister.h.

Referenced by nextInt(), restore(), save(), and setSeed().

◆ m_savedEngine

std::unique_ptr<std::mt19937> Mantid::Kernel::MersenneTwister::m_savedEngine

private

A generator that will take the value when save is requested.

Pointer so that it is only instantiated when required

Definition at line 78 of file MersenneTwister.h.

Referenced by restore(), save(), and setSeed().

◆ m_seed

std::mt19937::result_type Mantid::Kernel::MersenneTwister::m_seed

private

The current seed.

Definition at line 75 of file MersenneTwister.h.

Referenced by restart(), and setSeed().

◆ m_start

double Mantid::Kernel::MersenneTwister::m_start

private

Minimum in range.

Definition at line 71 of file MersenneTwister.h.

Referenced by setRange().

◆ uniformRealDistribution

std::uniform_real_distribution<double> Mantid::Kernel::MersenneTwister::uniformRealDistribution

private

Uniform Real distribution.

Definition at line 69 of file MersenneTwister.h.

Referenced by setRange().

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

Framework/Kernel/inc/MantidKernel/MersenneTwister.h
Framework/Kernel/src/MersenneTwister.cpp

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MersenneTwister() [1/5]

◆ MersenneTwister() [2/5]

◆ MersenneTwister() [3/5]

◆ MersenneTwister() [4/5]

◆ MersenneTwister() [5/5]

Member Function Documentation

◆ max()

◆ min()

◆ nextInt()

◆ nextValue() [1/2]

◆ nextValue() [2/2]

◆ operator=()

◆ restart()

◆ restore()

◆ save()

◆ setRange()

◆ setSeed()

Member Data Documentation

◆ m_end

◆ m_engine

◆ m_savedEngine

◆ m_seed

◆ m_start

◆ uniformRealDistribution