Struct HallOfFame 

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

Per-population archive of past champions, capped at a fixed capacity.

Each update appends the current generation’s best individual (highest fitness, canonical maximise convention) to each population’s archive. When an archive would exceed capacity the single worst-fitness (lowest) member is dropped, so the archive always retains the capacity best champions seen across the whole run.

The capacity is computed by capacity_for as max(10, pop_size / 5) (Rosin & Belew sizing).

Invariants

• All archives share a single genome_dim; v1 co-evolution is bi-population over equal-width genomes. Asymmetric genome widths are out of scope.
• archives()[p].dims()[0] <= capacity after every update.

Implementations

impl<B: Backend> HallOfFame<B>

pub fn new( num_populations: usize, capacity: usize, genome_dim: usize, device: &<B as BackendTypes>::Device, ) -> Self

Build an empty hall of fame for num_populations populations.

Each archive starts as a (0, genome_dim) tensor and grows by one row per update until capacity is reached.

pub fn capacity_for(pop_size: usize) -> usize

Recommended capacity for a population of pop_size: max(10, pop_size / 5).

pub fn update( &mut self, populations: &[Tensor<B, 2>], fitnesses: &[Tensor<B, 1>], )

Insert the best individual of each population into its archive.

For population p, the highest-fitness row of populations[p] is appended to archives[p] (canonical maximise: higher is better). If that pushes the archive past capacity, the single lowest-fitness (worst) archived member is removed. Empty populations are skipped.

This method is sense-blind: it argmaxes highest = best and evicts lowest = worst, which is correct only in canonical (maximise) space. The caller is responsible for passing canonical fitness — for a Minimize objective the natural cost must be negated first, or the highest-cost (worst) individual would be crowned champion.

Panics

Panics if a population’s fitness tensor cannot be read back to host as f32 (a device→host transfer failure). A legitimately empty population is a valid non-error host-read and is skipped, not a panic.

pub fn archives(&self) -> &[Tensor<B, 2>]

Borrow the per-population champion archives.

pub fn capacity(&self) -> usize

The per-population capacity cap.

Trait Implementations

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

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

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

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

Formats the value using the given formatter.