Multiply-With-Carry Random Number Generator

This library implements the complementary multiply-with-carry algorithm created by George Marsaglia as a LuaRock.

It is designed for use in games. It is meant to be deterministic: given a certain intial seed, the sequence of results provided by the library should be the same.

Installation

Install using LuaRocks:

luarocks install mwcrng

That allows you to access this library in your Lua files/interpreter:

mwcrng = require("mwcrng")

Alternatively, if running Lua as a C library, you could run this function on your Lua State:

luaopen_mwcrng(L);

Functions

mwcrng.init(seed)

Initializes the library, and must be called before any other function. The argument must be an integer. The result of os.time() is a good choice of seed if you don't have a particular one you wish to use.

mwcrng.coin()

Simulates a coin toss. Has a 50% chance of returning true, and a 50% chance of returning false.

mwcrng.dice(throws, sides)

Simulates throwing throws number of dice, each with an equal chance of providing any result from 1 to sides inclusive. The result is the sum of all the values of all the simulated dice.

For example, dice(1,6) would return any value from 1 to 6 inclusive with equal probability.

dice(2,4) would return any value from 2 to 8 inclusive, but not with equal probability: values of exactly 2 and 8 would be relatively unlikely.