Crate roulette_wheel [−] [src]

A Little implementation of the roulette-wheel principle, `RouletteWheel<T>`. https://wikipedia.org/wiki/Fitness_proportionate_selection

Examples usages

```use roulette_wheel::RouletteWheel;

fn evaluate(individual: &i32) -> f32 { *individual as f32 } // mmm...!

let population: Vec<_> = (1..10).into_iter().collect();
let fitnesses: Vec<_> = population.iter().map(|ind| evaluate(ind)).collect();

let rw: RouletteWheel<_> = fitnesses.into_iter().zip(population).collect();

// let's collect the individuals in the order in which the roulette wheel gives them
let individuals: Vec<_> = rw.into_iter().map(|(_, ind)| ind).collect();
// rw.select_iter() will not consume the roulette wheel
// while rw.into_iter() will !

fn crossover(mother: &i32, _father: &i32) -> i32 { mother.clone() } // unimplemented!()

// now merge each individual by couples
let new_population: Vec<_> = individuals.chunks(2)
.filter(|couple| couple.len() == 2)
.map(|couple| {
let (mother, father) = (couple[0], couple[1]);
crossover(&mother, &father)
// note: for this example we return only one individual,
//       the population will shrink
//       .flat_map() can resolve this issue
}).collect();```

Structs

 IntoSelectIter An iterator that moves out of a RouletteWheel. RouletteWheel A roulette-wheel container SelectIter Immutable RouletteWheel iterator