sampFiles::RanDraw Class Reference

Random number generating class. More...

#include <random.hpp>

Public Member Functions
	RanDraw ()
	Default constructor. More...
	~RanDraw ()
	Destructor.
	RanDraw (const RanDraw &old)=default
	Copy constructor. More...
	RanDraw (RanDraw &&old)=default
	Move constructor. More...
RanDraw &	operator= (const RanDraw &old)=default
	Copy assignment. More...
RanDraw &	operator= (RanDraw &&old)=default
	Move assignment. More...
volatile uint64_t	ranInt ()
	Generate random integer. More...
volatile double	runif ()
	Generate a uniform deviate. More...
volatile double	runifnz ()
	Generate a non-zero uniform deviate. More...
volatile uint64_t	vitterA (const double &n, const double &N)
	Sample from Vitter's distribution, method A. More...
volatile uint64_t	vitter (const double &n, const double &N)
	Sample from Vitter's distribution, method D. More...

Detailed Description

Random number generating class.

Generates (pseudo-)random deviates from a number of distributions. If hardware random numbers are supported, uses them. Otherwise, falls back to 64-bit MT19937 ("Mersenne Twister").

Constructor & Destructor Documentation

RanDraw() [1/3]

RanDraw::RanDraw

(

)

Default constructor.

Checks if the processor provides hardware random number support. Seeds the Mersenne Twister if not. Throws "CPU_unsupported" string object if the CPU is not AMD or Intel.

RanDraw() [2/3]

sampFiles::RanDraw::RanDraw ( const RanDraw &  old )

default

Copy constructor.

Parameters

[in]

old

pbject to be copied

RanDraw() [3/3]

sampFiles::RanDraw::RanDraw ( RanDraw &&  old )

default

Move constructor.

Parameters

[in]

old

pbject to be moved

Member Function Documentation

operator=() [1/2]

RanDraw& sampFiles::RanDraw::operator= ( const RanDraw &  old )

default

Copy assignment.

Parameters

[in]

old

pbject to be copied

operator=() [2/2]

RanDraw& sampFiles::RanDraw::operator= ( RanDraw &&  old )

default

Move assignment.

Parameters

[in]

old

pbject to be moved

ranInt()

volatile uint64_t sampFiles::RanDraw::ranInt ( )

inline

Generate random integer.

Returns

An unsigned random 64-bit integer

runif()

volatile double sampFiles::RanDraw::runif ( )

inline

Generate a uniform deviate.

Returns

A double-precision value from the \( U[0,1]\) distribution

runifnz()

volatile double RanDraw::runifnz

(

)

Generate a non-zero uniform deviate.

Returns

A double-precision value from the \( U(0,1]\) distribution

vitter()

volatile uint64_t RanDraw::vitter	(	const double &	n,
		const double &	N
	)

Sample from Vitter's distribution, method D.

Given the number of remaining records in a file \(N\) and the number of records \(n\) remaining to be selected, sample the number of records to skip over. This function implements Vitter's [2] [3] method D. It is useful for online one-pass sampling of records from a file. While the inputs are integer, we pass them in as double because that is more efficient for calculations.

Parameters

[in]	n	number of records remaining to be picked
[in]	N	number of remaining records in the file

Returns

the number of records to skip

vitterA()

volatile uint64_t RanDraw::vitterA	(	const double &	n,
		const double &	N
	)

Sample from Vitter's distribution, method A.

Given the number of remaining records in a file \(N\) and the number of records \(n\) remaining to be selected, sample the number of records to skip over. This function implements Vitter's [2] [3] method A. It is useful for online one-pass sampling of records from a file. While the inputs are integer, we pass them in as double because that is more efficient for calculations.

Parameters

[in]	n	number of records remaining to be picked
[in]	N	number of remaining records in the file

Returns

the number of records to skip

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

• random.hpp
• random.cpp