Random.hpp

A versatile pseudo-random-number generator. Status: RELEASE.

Defines

INCLUDE_EMP_MATH_RANDOM_HPP_GUARD

Typedefs

using RandomBest = Random_Base<Random_Xoshiro256pp>

using Random32 = Random_Base<Random_MSWS>

using RandomFast = Random_Base<Random_Xorshift>

using Random = RandomBest 

Functions

template<typename ForwardIterator, typename OutputIterator, typename RNG> void sample_with_replacement(ForwardIterator first, ForwardIterator last, OutputIterator ofirst, OutputIterator olast, RNG &rng) noexcept: Draw a sample (with replacement) from an input range, copying to the output range.

template<typename ENGINE_T> class Random_Base

#include <Random.hpp>

Public Types

enum Prob

Enumeration for common probabilities. (not class, so can be referred to as e.g., Random::PROB_50)

Values:

enumerator PROB_0

enumerator PROB_12_5

enumerator PROB_25

enumerator PROB_37_5

enumerator PROB_50

enumerator PROB_62_5

enumerator PROB_75

enumerator PROB_87_5

enumerator PROB_100

using mem_ptr_t = Ptr<uint8_t>: Shortcut type for all functions that deal with chunks of memory.

Public Functions

inline Random_Base(uint64_t seed = 0) noexcept: Set up the random generator object with an optional seed value (0 = based on time and ptr).

inline void StepEngine() noexcept: Advance pseudorandom number generation engine one step.

inline uint64_t GetSeed() const noexcept

Returns:: The current seed used to initialize this pseudo-random sequence.

inline std::string GetEngineType()

Returns:: The type name of the engine.

inline void ResetSeed(uint64_t seed) noexcept: Starts a new sequence of pseudo random numbers. A negative seed means that the random number generator gets its seed from the current system time and the process memory.

inline double GetDouble() noexcept

Returns:: A pseudo-random double value between [0.0, 1.0)

inline double GetDouble(const double max) noexcept

Returns:: A pseudo-random double value between [0.0, max)

inline double GetDouble(const double min, const double max) noexcept

Returns:: A pseudo-random double value between [min, max)

inline double GetDouble(const Range<double> range) noexcept

Returns:: A pseudo-random double in the provided range.

inline double GetDoubleNonZero() noexcept

Returns:: A pseudo-random double value between (0.0, 1.0)

inline uint64_t GetUInt() noexcept

Returns:: A pseudo-random 64-bit (8 byte) unsigned int value.

template<typename T> inline uint64_t GetUInt(const T max) noexcept

Returns:: A pseudo-random 64-bit unsigned int value between [0, max)

template<typename T1, typename T2> inline uint64_t GetUInt(const T1 min, const T2 max) noexcept

Returns:: A pseudo-random 64-bit unsigned int value between [min, max)

template<typename T> inline uint64_t GetUInt(const Range<T> range) noexcept

Returns:: A pseudo-random 64-bit unsigned int value in the provided range.

inline uint32_t GetUInt32() noexcept

Returns:: A pseudo-random 32-bit (4 byte) unsigned int value.

template<typename T> inline uint32_t GetUInt32(const T max) noexcept

Returns:: A pseudo-random 32-bit unsigned int value between [0, max)

template<typename T1, typename T2> inline uint32_t GetUInt32(const T1 min, const T2 max) noexcept

Returns:: A pseudo-random 32-bit unsigned int value between [min, max)

template<typename T> inline uint32_t GetUInt32(const Range<T> range) noexcept

Returns:: A pseudo-random 32-bit unsigned int value in the provided range.

inline uint64_t GetUInt64() noexcept

Returns:: A pseudo-random 64-bit (8 byte) unsigned int value.

inline uint64_t GetUInt64(const uint64_t max) noexcept

Returns:: A pseudo-random 64-bit unsigned int value between [0, max) This is a high-precision accessor with perfectly even probabilities in the range.

template<typename T1, typename T2> inline uint64_t GetUInt64(const T1 min, const T2 max) noexcept

Returns:: A pseudo-random 64-bit unsigned int value between [min, max)

template<typename T> inline uint64_t GetUInt64(const Range<T> range) noexcept

Returns:: A pseudo-random 64-bit unsigned int value in the provided range.

inline size_t GetSizeT() noexcept

Returns:: A pseudo-random value that fits perfectly in size_t.

inline size_t GetSizeT(const size_t max) noexcept

Returns:: A pseudo-random size_t value between [0, max) This is a high-precision accessor with perfectly even probabilities in the range.

template<typename T1, typename T2> inline size_t GetSizeT(const T1 min, const T2 max) noexcept

Returns:: A pseudo-random 64-bit unsigned int value between [min, max)

template<typename T> inline size_t GetSizeT(const Range<T> range) noexcept

Returns:: A pseudo-random 64-bit unsigned int value in the provided range.

inline int GetInt(const int max) noexcept

Returns:: A pseudo-random int value in [0, max)

inline int GetInt(const int min, const int max) noexcept

Returns:: A pseudo-random int value in [min, max)

inline int GetInt(const Range<int> range) noexcept

Returns:: A pseudo-random int value in range

inline uint64_t GetBits12_5() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 12.5% chance of each bit being 1.

inline uint64_t GetBits25() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 25% chance of each bit being 1.

inline uint64_t GetBits37_5() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 37.5% chance of each bit being 1.

inline uint64_t GetBits50() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 50% chance of each bit being 1.

inline uint64_t GetBits62_5() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 62.5% chance of each bit being 1.

inline uint64_t GetBits75() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 75% chance of each bit being 1.

inline uint64_t GetBits87_5() noexcept

Returns:: A pseudo-random 64 bits (unsigned int) with a 87.5% chance of each bit being 1.

inline void RandFill(mem_ptr_t dest, const size_t num_bytes) noexcept: Randomize a contiguous segment of memory.

template<Prob PROB> inline void RandFillP(mem_ptr_t dest, const size_t num_bytes) noexcept: Randomize a contiguous segment of memory.

template<Prob PROB> inline void RandFillP(mem_ptr_t dest, [[maybe_unused]] const size_t num_bytes, size_t start_bit, size_t stop_bit) noexcept: Randomize a contiguous segment of memory between specified bit positions.

inline void RandFill0(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill12_5(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill25(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill37_5(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill50(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill62_5(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill75(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill87_5(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill100(mem_ptr_t dest, const size_t bytes) noexcept

inline void RandFill0(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill12_5(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill25(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill37_5(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill50(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill62_5(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill75(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill87_5(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill100(mem_ptr_t dest, const size_t bytes, size_t start_bit, size_t stop_bit) noexcept

inline void RandFill(mem_ptr_t dest, const size_t num_bytes, const double p) noexcept: Randomize a contiguous segment of memory with a given probability of ones.

inline void RandFill(mem_ptr_t dest, const size_t num_bytes, const double p, const size_t start_bit, const size_t stop_bit) noexcept: Randomize a contiguous segment of memory with a given probability of ones.

inline bool P(const double p) noexcept

Tests a random value [0,1) against a given probability p, and returns true of false.

Parameters:: p – The probability of the result being “true”.

inline uint8_t GetByte(const double p) noexcept: Full random byte with each bit being a one with a given probability.

inline double GetNormal() noexcept: Generate a random variable drawn from a unit normal distribution.

inline double GetNormal(const double mean, const double std)

Parameters:

mean – Center of distribution.
std – Standard deviation of distribution.

Returns:

A random variable drawn from a normal distribution.

inline uint64_t GetPoisson(const double n, const double p): Generate a random variable drawn from a Poisson distribution.

inline uint64_t GetPoisson(const double mean): Generate a random variable drawn from a Poisson distribution.

inline uint64_t GetBinomial(const uint64_t n, const double p)

Generate a random variable drawn from a Binomial distribution.

This function is exact, but slow.