Struct SampleRef 

pub struct SampleRef<'a> {
    pub features: &'a [f64],
    pub target: f64,
    pub weight: f64,
}

A borrowed observation that avoids Vec<f64> allocation.

Use this when features are already available as a contiguous slice (e.g., from Arrow arrays, memory-mapped data, or pre-allocated buffers).

Fields

features: &'a [f64]

Borrowed feature slice.

target: f64

Target value.

weight: f64

Sample weight (default 1.0).

Implementations

impl<'a> SampleRef<'a>

pub fn new(features: &'a [f64], target: f64) -> Self

Create a new sample reference with unit weight.

pub fn weighted(features: &'a [f64], target: f64, weight: f64) -> Self

Create a new sample reference with explicit weight.

Trait Implementations

impl<'a> Clone for SampleRef<'a>

fn clone(&self) -> SampleRef<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for SampleRef<'a>

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

Formats the value using the given formatter.

impl<'a> From<(&'a [f64], f64)> for SampleRef<'a>

fn from((features, target): (&'a [f64], f64)) -> Self

Converts to this type from the input type.

impl<'a> Observation for SampleRef<'a>

fn features(&self) -> &[f64]

The feature values for this observation.

fn target(&self) -> f64

The target value (regression) or class label (classification).

fn weight(&self) -> f64

Optional sample weight. Defaults to 1.0 (uniform).

impl<'a> Copy for SampleRef<'a>