Enum programinduction::GPSelection

pub enum GPSelection {
    Deterministic,
    Drift(f64),
    Hybrid(f64),
    Probabilistic,
    Resample,
}

The mechanism by which individuals are selected for inclusion in the population.

Variants

Deterministic

Deterministic implies a strict survival-of-the-fittest selection mechanism, in which the best individuals are always retained. An individual can only be removed from a population if a better-scoring individual arises to take its place.

Drift(f64)

Drift(alpha) implies a noisy survival-of-the-fittest selection mechanism, in which individuals are selected probabilistically without replacement from the combination of the population and offspring to form a new population. Offspring fitness is simply determined by the task, while the fitness of members of the pre-existing population is computed as a linear combination of their prior fitness and fitness on the current task, given as fitness_{:t} = alpha * fitness_{:t-1} + (1-alpha) * fitness_t. An individual can be removed from a population by lower-scoring individuals, though this is relatively unlikely.

Hybrid(f64)

Hybrid(deterministic_proportion) implies a selection mechanism in which some portion of the population is selected deterministically such that the best individuals are always retained. The remainder of the population is sampled without replacement from the remaining individuals. An individual can be removed from a population by lower-scoring individuals, though this is relatively unlikely, and impossible if the individual is considered one of the “best” in the population. The number of “best” individuals is floor(population.len() * deterministic_proportion). The deterministic_proportion should be between 0 and 1.

Probabilistic

Probabilistic implies a noisy survival-of-the-fittest selection mechanism, in which a population is selected probabilistically from a set of possible populations in proportion to its overall fitness. An individual can be removed from a population even by lower-scoring individuals, though this is relatively unlikely.

Resample

Resample implies that individuals are selected by sampling from the offspring with replacement, as in a particle filter.

Trait Implementations

impl<'de> Deserialize<'de> for GPSelection

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for GPSelection

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

where __S: Serializer,

Serialize this value into the given Serde serializer.