Struct Antithetic 

pub struct Antithetic;

Uniform sampling with antithetic pairs: trial 2k + 1 mirrors trial 2k.

History-dependent — see the crate documentation for why it cannot be stateless — and persists nothing. Construct it with Antithetic::new.

A unit struct, and that is the point: everything it needs is either handed to it per trial or already recorded in the study. A sampler holding interior mutability would owe the determinism contract an explanation, and would have to persist that state through [Sampler::state] to survive a resume.

Implementations

impl Antithetic

pub const fn new() -> Self

Creates the sampler.

Trait Implementations

impl Clone for Antithetic

fn clone(&self) -> Antithetic

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Antithetic

impl Debug for Antithetic

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

Formats the value using the given formatter.

impl Default for Antithetic

fn default() -> Antithetic

Returns the “default value” for a type.

impl Sampler for Antithetic

fn infer_relative_space(&self, study: &StudyView) -> Result<SpaceSchema>

The study’s declared space, or an empty one.

An empty schema is legal and means “sample everything independently”, which this sampler answers identically through sample_independent.

fn sample_relative( &self, study: &StudyView, trial: &TrialMeta, space: &SpaceSchema, ) -> Result<Assignment>

Draws every parameter of the joint space.

fn sample_independent( &self, study: &StudyView, trial: &TrialMeta, name: &str, dist: &Distribution, ) -> Result<ParamValue>

Draws one parameter the relative space did not cover.

Identical to what sample_relative would have produced for it: a parameter that migrates between the declared space and the define-by-run fallback must keep its value.

fn reseed(&self, _seed: u64)

Nothing to reseed.

The hook exists for a sampler with auxiliary randomness of its own. Every seed this one uses comes from [TrialMeta], which the framework has already made worker-independent, so the correct implementation is empty — not a hidden self.rng = … that would make a draw depend on which worker called it.

fn after_trial( &self, study: &StudyView, trial: &FrozenTrial, ) -> Result<(), Error>

Called once a trial reaches a terminal state.

fn state(&self) -> Result<Option<StateBlob>, Error>

The sampler’s persistable state, if it has any.

fn snapshots_space(&self) -> bool

Whether this sampler enumerates a snapshot of the space it was constructed with, rather than the space each ask presents.

fn reads_constraints(&self) -> bool

Whether this sampler reads FrozenTrial::constraints on the views it is asked with.

fn restore_state(&self, blob: &StateBlob) -> Result<(), Error>

Restores a sampler from a previously persisted blob.