Struct BaselineComparator 

pub struct BaselineComparator { /* private fields */ }

Compares multiple models by their rolling error and tracks the current best.

Each entry is identified by a name and maintains its own RollingMae. The comparator does not store models, only error metrics, so it can be used alongside any predictor.

Implementations

impl BaselineComparator

pub fn new(names: &[&str], window_size: usize) -> Result<Self, RillError>

Create a new comparator with one entry per name and the given window size.

Errors

Returns RillError::EmptyFeatures if names is empty, and RillError::InvalidParameter if names contains duplicates. A window_size of zero propagates RillError::InvalidWindowSize from the underlying RollingMae.

pub fn record( &mut self, index: usize, truth: f64, prediction: f64, ) -> Result<(), RillError>

Record a single (truth, prediction) observation against the entry at index.

Errors

Returns RillError::DimensionMismatch if index is out of bounds, and propagates any finiteness error from the underlying metric.

pub fn update_best(&mut self) -> Option<usize>

Recompute the best entry and return the new best index if it changed.

The best entry is the one with the lowest rolling MAE among entries that have at least one observation. If all entries are empty, the best index is cleared and the last switch reason is set to SwitchReason::InsufficientData.

Returns Some(new_index) when the best entry changes, and None otherwise.

pub const fn best_index(&self) -> Option<usize>

Index of the current best entry, or None if no entry has data.

pub fn best_name(&self) -> Option<&str>

Name of the current best entry, or None if no entry has data.

pub fn best_error(&self) -> Option<f64>

Rolling MAE of the current best entry, or None if unavailable.

pub fn entry_count(&self) -> usize

Number of tracked entries.

pub const fn switch_count(&self) -> u64

How many times the best entry has changed since construction or last reset.

pub const fn last_switch_reason(&self) -> Option<SwitchReason>

The reason for the most recent best-entry change (or InsufficientData).

pub fn entry(&self, index: usize) -> Option<&ComparatorEntry>

Borrow the entry at index, or None if out of bounds.

pub fn reset(&mut self)

Reset every entry’s rolling metric and sample count, and clear all best-entry tracking state.

Trait Implementations

impl Clone for BaselineComparator

fn clone(&self) -> BaselineComparator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BaselineComparator

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

Formats the value using the given formatter.