Struct ESConfig 

pub struct ESConfig {
    pub mu: usize,
    pub lambda: usize,
    pub selection: ESSelectionStrategy,
    pub initial_sigma: f64,
    pub self_adaptive: bool,
    pub recombination: RecombinationType,
    pub min_sigma: Option<f64>,
}

Configuration for Evolution Strategies

Fields

mu: usize

Number of parents (μ)

lambda: usize

Number of offspring (λ)

selection: ESSelectionStrategy

Selection strategy

initial_sigma: f64

Initial step size (σ)

self_adaptive: bool

Use self-adaptive mutation (evolve σ)

recombination: RecombinationType

Recombination type

min_sigma: Option<f64>

Problem-scaled lower bound on self-adaptive step sizes.

None resolves to 1e-8 * initial_sigma (see ESConfig::resolved_min_sigma), which guards against premature step-size collapse. This is distinct from the absolute underflow floor baked into StrategyParams, which only prevents σ reaching literal zero.

Implementations

impl ESConfig

pub fn resolved_min_sigma(&self) -> f64

Resolve the effective lower bound on self-adaptive step sizes.

Uses the explicitly configured min_sigma when set, otherwise a problem-scaled default of 1e-8 * initial_sigma.

pub fn mu_plus_lambda(mu: usize, lambda: usize) -> Self

Create a (μ+λ)-ES configuration

pub fn mu_comma_lambda(mu: usize, lambda: usize) -> Result<Self, EvolutionError>

Create a (μ,λ)-ES configuration

Trait Implementations

impl Clone for ESConfig

fn clone(&self) -> ESConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ESConfig

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

Formats the value using the given formatter.

impl Default for ESConfig

fn default() -> Self

Default configuration: (15, 100)-ES with mutative σ self-adaptation.

Selection defaults to MuCommaLambda (comma) because self-adaptation is enabled by default and elitist (plus) selection suppresses mutative step-size adaptation — see ESSelectionStrategy for the theory.