RNGT< UInt, a, c, m > Struct Template Reference

Public Types
typedef unsigned	result_type

Public Member Functions
	RNGT (const UInt s)
void	seed (const UInt s)
RNGT &	index (const UInt i)
unsigned	sample ()
unsigned	sample_range (const unsigned range)
unsigned	operator() ()

Static Public Member Functions
static constexpr unsigned	min ()
static constexpr unsigned	max ()

Public Attributes
UInt	x
UInt	key

Detailed Description

template<typename UInt, UInt a, UInt c, UInt m>
struct RNGT< UInt, a, c, m >

Definition at line 11 of file rng.h.

Member Typedef Documentation

result_type

template<typename UInt, UInt a, UInt c, UInt m>

typedef unsigned RNGT< UInt, a, c, m >::result_type

Definition at line 62 of file rng.h.

Constructor & Destructor Documentation

RNGT() [1/2]

template<typename UInt, UInt a, UInt c, UInt m>

RNGT< UInt, a, c, m >::RNGT ( )

inline

Definition at line 13 of file rng.h.

: x(), key() { seed(123451); }

RNGT() [2/2]

template<typename UInt, UInt a, UInt c, UInt m>

RNGT< UInt, a, c, m >::RNGT ( const UInt s )

inline

Definition at line 14 of file rng.h.

: x(), key() { seed(s); }

Member Function Documentation

seed()

template<typename UInt, UInt a, UInt c, UInt m>

void RNGT< UInt, a, c, m >::seed ( const UInt s )

inline

Definition at line 15 of file rng.h.

{ key= (s << 1) | 1; x= key; }

index()

template<typename UInt, UInt a, UInt c, UInt m>

RNGT & RNGT< UInt, a, c, m >::index ( const UInt i )

inline

Definition at line 17 of file rng.h.

    {
        UInt tmul= a;
        UInt tadd= c;
        UInt mul= 1;
        UInt add= 0;
        
        UInt delta= i;
        while(delta)
        {
            if(delta & 1)
            {
                mul= mul * tmul;
                add= add * tmul + tadd;
            }
            
            tadd= tmul * tadd + tadd;
            tmul= tmul * tmul;
            delta= delta >> 1;
        }
        
        x= mul * key + add;
        return *this;
    }

sample()

template<typename UInt, UInt a, UInt c, UInt m>

unsigned RNGT< UInt, a, c, m >::sample ( )

inline

Definition at line 42 of file rng.h.

{ x= (a*x+c) % m; return unsigned(x); }

sample_range()

template<typename UInt, UInt a, UInt c, UInt m>

unsigned RNGT< UInt, a, c, m >::sample_range ( const unsigned range )

inline

Definition at line 44 of file rng.h.

    {
        // Efficiently Generating a Number in a Range
        // cf http://www.pcg-random.org/posts/bounded-rands.html
        unsigned divisor= ((-range) / range) + 1; // (2^32) / range
        if(divisor == 0) return 0;
        
        while(true)
        {
            unsigned x= sample() / divisor;
            if(x < range) return x;
        }
    }

operator()()

template<typename UInt, UInt a, UInt c, UInt m>

unsigned RNGT< UInt, a, c, m >::operator() ( )

inline

Definition at line 59 of file rng.h.

{ return sample(); }

min()

template<typename UInt, UInt a, UInt c, UInt m>

constexpr unsigned RNGT< UInt, a, c, m >::min ( )

inlinestaticconstexpr

Definition at line 60 of file rng.h.

{ return 0; }

max()

template<typename UInt, UInt a, UInt c, UInt m>

constexpr unsigned RNGT< UInt, a, c, m >::max ( )

inlinestaticconstexpr

Definition at line 61 of file rng.h.

{ return unsigned(m-1); }

Member Data Documentation

x

template<typename UInt, UInt a, UInt c, UInt m>

UInt RNGT< UInt, a, c, m >::x

Definition at line 65 of file rng.h.

key

template<typename UInt, UInt a, UInt c, UInt m>

UInt RNGT< UInt, a, c, m >::key

Definition at line 66 of file rng.h.

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

• src/gKit/rng.h