Struct Tarpeian 

pub struct Tarpeian<S> { /* private fields */ }

Tarpeian bloat control (Poli 2003): a selection in which some of the genomes larger than the population’s mean size count as invalid.

Once per call, each genome larger than the mean Genome::len (a tree’s number of nodes) is marked with probability rate, independently, and select then chooses as if the marked individuals were invalid: worse than every other. The more individuals above the mean, the more are held back, whatever the scale of the fitness values.

Poli marks new individuals before they’re evaluated and skips their evaluation. As a selection, this keeps the effect on selection, not the saved evaluations, which would need the algorithm’s cooperation.

use genoxide::prelude::*;

let select = Tarpeian::new(Tournament::new(7)?, 0.3)?;
assert_eq!(select.rate(), 0.3);
assert!(Tarpeian::new(Tournament::new(7)?, 0.0).is_err());

Implementations

impl<S: Select> Tarpeian<S>

pub fn new(select: S, rate: f64) -> Result<Self>

select, with each genome larger than the mean size counted as invalid with probability rate, greater than 0 and at most 1.

Errors

Error::InvalidSetting (setting tarpeian_rate) for a rate outside (0, 1].

pub fn inner(&self) -> &S

The selection it wraps.

pub fn rate(&self) -> f64

The probability that a genome larger than the mean counts as invalid.

Trait Implementations

impl<S: Clone> Clone for Tarpeian<S>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<S: Debug> Debug for Tarpeian<S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de, S> Deserialize<'de> for Tarpeian<S>

where S: Deserialize<'de>,

Available on crate feature serde only.

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<S: PartialEq> PartialEq for Tarpeian<S>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<S: Select> Select for Tarpeian<S>

fn select<G: Genome>( &self, population: &Population<G>, objective: Objective, count: usize, rng: &mut StreamRng, ) -> Vec<usize>

Selects count parents, with replacement: the positions of the selected individuals.

impl<S> Serialize for Tarpeian<S>

where S: Serialize,

Available on crate feature serde only.

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<S: PartialEq> StructuralPartialEq for Tarpeian<S>