Enum ScaleMode 

#[non_exhaustive]
pub enum ScaleMode {
    Empirical,
    TreeChain,
}

Available on crate feature alloc only.

How DistributionalSGBT estimates uncertainty (σ).

• Empirical (default): tracks an EWMA of squared prediction errors. σ = sqrt(ewma_sq_err). Always calibrated, zero tuning, O(1) compute. Use this when σ drives learning-rate modulation (σ high → learn faster).

• TreeChain: trains a full second ensemble of Hoeffding trees to predict log(σ) from features (NGBoost-style dual chain). Gives feature-conditional uncertainty but requires strong signal in the scale gradients.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Empirical

Empirical sigma: EWMA of squared prediction errors (default).

TreeChain

Tree-chain: a second boosting chain learns log(sigma) from features.

Trait Implementations

impl Clone for ScaleMode

fn clone(&self) -> ScaleMode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ScaleMode

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

Formats the value using the given formatter.

impl Default for ScaleMode

fn default() -> ScaleMode

Returns the “default value” for a type.

impl PartialEq for ScaleMode

fn eq(&self, other: &ScaleMode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ScaleMode

impl Eq for ScaleMode

impl StructuralPartialEq for ScaleMode