imneme’s gists

imneme / badseed.cpp

Last active August 29, 2015 14:19

	// badseed:
	// Provides examples showing std::seed_seq is not a bijection
	// i.e., that some seeds get repeated for different inputs
	// and thus some other seeds must never be generated

	#include <random>
	#include <iostream>
	#include <iomanip>
	#include <cstddef>

imneme / randutils.hpp

Last active September 25, 2024 13:41

Addresses common issues with C++11 random number generation; makes good seeding easier, and makes using RNGs easy while retaining all the power.

	/*
	* Random-Number Utilities (randutil)
	* Addresses common issues with C++11 random number generation.
	* Makes good seeding easier, and makes using RNGs easy while retaining
	* all the power.
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2015-2022 Melissa E. O'Neill
	*

imneme / xorshift.hpp

Last active February 15, 2023 17:47

A Family of Truncated XorShift* PRNGs

	#ifndef XORSHIFT_HPP_INCLUDED
	#define XORSHIFT_HPP_INCLUDED 1

	/*
	* A C++ implementation of a family of truncated XorShift* generators.
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2017-19 Melissa E. O'Neill
	*

imneme / xoroshiro.hpp

Last active December 3, 2020 22:37

A C++ implementation of a family of Xoroshiro+ generators

	#ifndef XOROSHIRO_HPP_INCLUDED
	#define XOROSHIRO_HPP_INCLUDED 1

	/*
	* A C++ implementation of a family of Xoroshiro generators.
	*
	* See:
	* https://en.wikipedia.org/wiki/Xoroshiro128%2B
	* http://xoroshiro.di.unimi.it/xoroshiro128plus.c
	*

imneme / jsf.hpp

Created May 28, 2018 02:40

A C++ Implementation of Bob Jenkins's Small Fast Noncryptographic PRNG (JSF)

	#ifndef JSF_HPP_INCLUDED
	#define JSF_HPP_INCLUDED 1

	/*
	* A C++ implementation of a Bob Jenkins Small Fast (Noncryptographic) PRNGs
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2018 Melissa E. O'Neill
	*

imneme / gjrand.hpp

Created May 28, 2018 07:45

A C++ implementation of David Blackman's GJrand PRNG(s)

	#ifndef GJRAND_HPP_INCLUDED
	#define GJRAND_HPP_INCLUDED 1

	/*
	* A C++ implementation of David Blackman's GJrand PRNG(s)
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2018 Melissa E. O'Neill
	*

imneme / sfc.hpp

Last active July 6, 2024 10:23

A C++ implementation of Chris Doty-Humphrey's SFC PRNG(s)

	#ifndef SFC_HPP_INCLUDED
	#define SFC_HPP_INCLUDED 1

	/*
	* A C++ implementation of Chris Doty-Humphrey's SFC PRNG(s)
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2018 Melissa E. O'Neill
	*

imneme / lehmer.hpp

Created June 9, 2018 20:39

A C++ implementation of 128-bit Lehmer-style PRNGs

	#ifndef LEHMER_HPP_INCLUDED
	#define LEHMER_HPP_INCLUDED 1

	/*
	* A C++ implementation of fast, 128-bit, Lehmer-style PRNGs
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2018 Melissa E. O'Neill
	*

imneme / rng_adapters.hpp

Created June 9, 2018 20:43

A C++ implementation of a set of PRNG adapters

	#ifndef RND_ADAPTERS_HPP_INCLUDED
	#define RND_ADAPTERS_HPP_INCLUDED 1

	/*
	* A C++ implementation of a set of PRNG adapters.
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2018 Melissa E. O'Neill
	*

imneme / xoshiro-bad-repeats.c

Created June 11, 2018 03:55

Xoshiro256** Bad Repeats Demonstration

	/*
	* Xoshiro256** Bad Repeats Demonstration
	*
	* gcc -std=c99 -Wall -o xoshiro-bad-repeats xoshiro-bad-repeats.c
	* ./xoshiro-bad-repeats \| less
	*
	* In a PRNG the size of Xoshiro256**, we should expect about 10 "5-in-7"
	* repeats. Xoshiro256** has more than 18 billion billion of them, which
	* is rather too many. In fact, the number of bad repeats is larger than
	* the 2**64 range of the generator!

M.E. O'Neill imneme