Enum DistanceMetric 

pub enum DistanceMetric {
    L2,
    Cosine,
    Angular,
    InnerProduct,
}

Distance metric for dense vectors.

This is primarily used for evaluation utilities and as a common vocabulary in docs. Individual index implementations may hard-code a metric today.

Variants

L2

Euclidean (L2) distance.

Cosine

Cosine distance $1 - \cos(a,b)$.

Angular

Angular distance $\arccos(\cos(a,b)) / \pi$, in [0,1].

InnerProduct

Inner product distance $-\langle a,b\rangle$ (for maximum inner product search).

Implementations

impl DistanceMetric

pub fn distance(self, a: &[f32], b: &[f32]) -> f32

Compute distance between two vectors.

If dimensions mismatch, this returns f32::INFINITY (so it is never selected as a nearest neighbor).

Trait Implementations

impl Clone for DistanceMetric

fn clone(&self) -> DistanceMetric

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DistanceMetric

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

Formats the value using the given formatter.

impl PartialEq for DistanceMetric

fn eq(&self, other: &DistanceMetric) -> 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 DistanceMetric

impl Eq for DistanceMetric

impl StructuralPartialEq for DistanceMetric