Struct RouletteWheel

Source

pub struct RouletteWheel<T> { /* private fields */ }

Expand description

A roulette-wheel container

Implementations§

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impl<T> RouletteWheel<T>

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pub fn new() -> RouletteWheel<T>

create a new empty random-wheel.

§Example

use roulette_wheel::RouletteWheel;

let rw = RouletteWheel::<u8>::new();

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pub fn with_capacity(cap: usize) -> RouletteWheel<T>

Creates an empty RouletteWheel with space for at least n elements.

§Example

use roulette_wheel::RouletteWheel;

let rw = RouletteWheel::<u8>::with_capacity(15);

assert_eq!(rw.len(), 0);

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pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be inserted. The collection may reserve more space to avoid frequent reallocations.

§Example

use roulette_wheel::RouletteWheel;

let mut rw = RouletteWheel::<u8>::new();
rw.reserve(20);

assert_eq!(rw.len(), 0);

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pub fn len(&self) -> usize

Returns the number of elements in the wheel.

§Example

use roulette_wheel::RouletteWheel;

let rw: RouletteWheel<_> = [(0.1, 10), (0.2, 15), (0.5, 20)].iter().cloned().collect();

assert_eq!(rw.len(), 3);

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pub fn is_empty(&self) -> bool

Returns true if empty else return false.

§Example

use roulette_wheel::RouletteWheel;

let empty_rw = RouletteWheel::<u8>::new();

assert_eq!(empty_rw.is_empty(), true);

let non_empty_rw: RouletteWheel<_> = [(0.1, 10), (0.2, 15), (0.5, 20)].iter().cloned().collect();

assert_eq!(non_empty_rw.is_empty(), false);

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pub fn clear(&mut self)

Remove all elements in this wheel.

§Example

use roulette_wheel::RouletteWheel;

let mut rw: RouletteWheel<_> = [(0.1, 10), (0.2, 15), (0.5, 20)].iter().cloned().collect();

assert_eq!(rw.len(), 3);

rw.clear();

assert_eq!(rw.len(), 0);

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pub fn push(&mut self, fitness: f32, individual: T)

Add an element associated with a probability.

§Panics

This function might panic if the fitness is less than zero or if the total fitness gives a non-finite fitness (Inf).

§Example

use roulette_wheel::RouletteWheel;

let mut rw = RouletteWheel::new();

rw.push(1.0, 'r');
rw.push(1.0, 'c');
rw.push(1.0, 'a');

assert_eq!(rw.len(), 3);

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pub unsafe fn unchecked_push(&mut self, fitness: f32, individual: T)

Add an element associated with a probability. This unsafe function doesn’t check for total fitness overflow nether fitness positivity.

§Example

use roulette_wheel::RouletteWheel;

let mut rw = RouletteWheel::new();

unsafe { rw.unchecked_push(1.0, 'r') };
unsafe { rw.unchecked_push(1.0, 'c') };
unsafe { rw.unchecked_push(1.0, 'a') };

assert_eq!(rw.len(), 3);

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pub fn total_fitness(&self) -> f32

Returns the sum of all individual fitnesses.

§Example

use roulette_wheel::RouletteWheel;

let mut rw = RouletteWheel::new();

rw.push(3.0, 'r');
rw.push(2.0, 'c');
rw.push(1.5, 'a');

assert_eq!(rw.total_fitness(), 6.5);

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pub fn select_iter(&self) -> SelectIter<'_, ThreadRng, T> ⓘ

Returns an iterator over the RouletteWheel.

§Examples

use roulette_wheel::RouletteWheel;

let rw: RouletteWheel<_> = [(0.1, 10), (0.2, 15), (0.5, 20)].iter().cloned().collect();
let mut iterator = rw.select_iter();

assert_eq!(iterator.next(), Some((0.5, &20)));
assert_eq!(iterator.next(), Some((0.1, &10)));
assert_eq!(iterator.next(), Some((0.2, &15)));
assert_eq!(iterator.next(), None);