Struct EpsilonFeasibility 

pub struct EpsilonFeasibility { /* private fields */ }

ε-constrained feasibility — a relaxed version of Deb’s rule that treats solutions with violation ≤ ε as “feasible” for comparison purposes.

The ε threshold is adapted over generations: it starts at a user-specified epsilon_0 and decreases to 0 following a schedule, gradually tightening the feasibility criterion.

References

Takahama, T. & Sakai, S. (2006). Constrained optimization by the ε constrained differential evolution with gradient-based mutation and feasible elites. IEEE CEC 2006.

Implementations

impl EpsilonFeasibility

pub fn new( epsilon_0: f64, t_c: usize, cp: f64, schedule: EpsilonSchedule, ) -> OptimizeResult<Self>

Create a new ε-feasibility handler.

Arguments

• epsilon_0 — Initial ε threshold (must be ≥ 0).
• t_c — Generation at which ε → 0 (must be > 0).
• cp — Control parameter for the schedule.
• schedule — Decay schedule.

pub fn epsilon(&self) -> f64

Current ε threshold.

pub fn step(&mut self)

Advance to the next generation and update ε accordingly.

pub fn compare( &self, f_a: f64, viol_a: &ViolationSummary, f_b: f64, viol_b: &ViolationSummary, ) -> Ordering

Compare two solutions using the ε-constrained rule.

A solution with violation ≤ ε is treated as “feasible” for this comparison. The rule is otherwise identical to FeasibilityRule.

Trait Implementations

impl Clone for EpsilonFeasibility

fn clone(&self) -> EpsilonFeasibility

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EpsilonFeasibility

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

Formats the value using the given formatter.