Crate roulette

A Rust implementation of roulette wheel selection using the Alias Method. This can be used to simulate a loaded die and similar situations.

Initialization takes O(n) time; choosing a random element takes O(1) time. This is far faster than naive algorithms (the most common of which is commonly known as ‘roulette wheel selection’). For an in-depth explanation of the algorithm, see http://www.keithschwarz.com/darts-dice-coins/.

This code was translated from http://www.keithschwarz.com/interesting/code/?dir=alias-method.

Example

extern crate rand;
extern crate roulette;

use roulette::Roulette;

fn main() {
    let mut rng = rand::thread_rng();
    let roulette = Roulette::new(vec![('a', 1.0), ('b', 1.0), ('c', 0.5), ('d', 0.0)]);
    for _ in 0..10 {
        let rand = roulette.sample(&mut rng);
        println!("{}", rand);
    }
}

Structs

Roulette

An efficient implementation of roulette wheel selection. This can be used to simulate a loaded die.