Struct NeatStrategy 

pub struct NeatStrategy<B: Backend> { /* private fields */ }

Custom NEAT harness. Does not implement Strategy — see the module docs.

Implementations

impl<B: Backend> NeatStrategy<B>

pub fn new() -> Self

Build a new (stateless) NEAT harness.

pub fn init( &self, params: &NeatParams, rng: &mut dyn Rng, device: &<B as BackendTypes>::Device, ) -> NeatState

Build the initial state: a per-run registry plus pop_size minimal genomes (aligned ids, per-individual random weights from one SeedPurpose::Init substream).

device is part of the harness signature for symmetry with the tensor strategies; NEAT genomes are host-side, so it is unused here.

Panics

Panics if weight_init_std is non-finite (+∞ or NaN).

pub fn ask( &self, params: &NeatParams, state: &NeatState, rng: &mut dyn Rng, ) -> (Vec<TopologyGenome>, NeatState)

Propose the next population.

Before the first tell (resident fitness still empty), the unchanged resident population is returned for evaluation. Afterwards the already-speciated residents drive reproduction: stagnant species are removed (top-K protected), offspring are apportioned by size-adjusted fitness (largest-remainder, summing exactly to pop_size), and each species contributes its champion unchanged (if large enough) plus offspring from intra-species crossover (rare interspecies mating) or mutation-only, all followed by the four mutation operators. Four StdRng substreams (selection, crossover, mutation, misc) keep operator RNG independent.

pub fn tell( &self, params: &NeatParams, population: Vec<TopologyGenome>, fitness: Vec<f32>, state: NeatState, rng: &mut dyn Rng, ) -> NeatState

Install the evaluated population and its (maximization) fitness, speciate, update per-species best/stagnation and the global best-so-far, and bump the generation.

Speciation lives here — not in ask — because this is the only point where the new population, its fitness, and the prior species’ cloned representatives all coexist consistently (so member indices stay valid and each species’ next representative is cloned from a live member).

Fitness hygiene

This is NEAT’s driver chokepoint (ADR 0034): NEAT is its own driver and does not run through EvolutionaryHarness, so there is no harness above it to sanitize fitness. tell therefore applies sanitize_fitness to the incoming fitness (NaN → −∞, +∞ → f32::MAX, −∞ and finite pass through) before it is stored or handed to species::speciate, so a non-finite fitness can never poison speciation, offspring apportionment, or best-so-far tracking.

Panics

Panics if population.len() differs from fitness.len().

pub fn best<'s>( &self, state: &'s NeatState, ) -> Option<(&'s TopologyGenome, f32)>

Best genome and its fitness seen across all generations.

Returns None before the first tell.

Trait Implementations

impl<B: Clone + Backend> Clone for NeatStrategy<B>

fn clone(&self) -> NeatStrategy<B>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<B: Copy + Backend> Copy for NeatStrategy<B>

impl<B: Debug + Backend> Debug for NeatStrategy<B>

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

Formats the value using the given formatter.

impl<B: Default + Backend> Default for NeatStrategy<B>

fn default() -> NeatStrategy<B>

Returns the “default value” for a type.