Struct Kswin 

pub struct Kswin { /* private fields */ }

KSWIN (Kolmogorov-Smirnov Windowing) drift detector.

Detects distribution changes by comparing two fixed-size windows with a two-sample KS test. Unlike mean-based detectors (Page-Hinkley, ADWIN), KSWIN is sensitive to distribution shape changes (variance, skewness, multimodality), not just mean shifts.

The KS test p-value is computed via the Marsaglia-Tsang-Wang algorithm; no external statistics crate is required.

Examples

use rill_ml::drift::{DriftDetector, DriftLevel, Kswin, KswinConfig};

let mut kswin_config = KswinConfig::default();
kswin_config.alpha = 0.01;
kswin_config.window_size = 50;
kswin_config.check_interval = 50;
let mut kswin = Kswin::new(kswin_config).unwrap();

// Stable stream around 0.
for _ in 0..100 {
    kswin.update(0.0).unwrap();
}
assert_eq!(kswin.level(), DriftLevel::None);

// Distribution shifts to mean 5.
for _ in 0..100 {
    kswin.update(5.0).unwrap();
}
// KSWIN should detect the distribution change.
assert!(kswin.samples_seen() > 100);

Implementations

impl Kswin

pub fn new(config: KswinConfig) -> Result<Self, RillError>

Create a new KSWIN detector with the given configuration.

Returns an error if:

• alpha is not in (0, 1).
• window_size is zero.
• check_interval is zero.

pub const fn last_statistic(&self) -> f64

The last computed KS statistic D (max CDF difference).

pub const fn last_pvalue(&self) -> f64

The last computed p-value from the KS test.

pub fn reference_window_len(&self) -> usize

The number of values currently in the reference window.

pub fn current_window_len(&self) -> usize

The number of values currently in the current window.

pub const fn config(&self) -> &KswinConfig

The configuration of this detector.

pub fn export_state_v1(&self) -> KswinPortableStateV1

Export the stable portable state.

pub fn restore_state_v1( config: KswinConfig, state: KswinPortableStateV1, ) -> Result<Self, RillError>

Restore from a validated portable state with exact config matching.

Trait Implementations

impl Clone for Kswin

fn clone(&self) -> Kswin

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Kswin

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

Formats the value using the given formatter.

impl Default for Kswin

fn default() -> Self

Returns the “default value” for a type.

impl DriftDetector for Kswin

fn update(&mut self, value: f64) -> Result<DriftLevel, RillError>

Update the detector with a new scalar observation.

fn detected(&self) -> bool

Returns true if the detector currently reports a confirmed drift.

fn warning(&self) -> bool

Returns true if the detector currently reports a warning.

fn level(&self) -> DriftLevel

The current drift level.

fn samples_seen(&self) -> u64

Number of observations incorporated so far.

fn reset(&mut self)

Reset the detector to its initial (no-data) state.

fn last_value(&self) -> f64

The detector-specific statistic value from the last update.