Enum DistanceMetric 

#[non_exhaustive]
pub enum DistanceMetric {
    Cosine,
    DotProduct,
    Euclidean,
    Manhattan,
    Hamming,
}

The metric used to measure distance (or similarity) between two vectors.

Which metric is valid depends on how the vectors were produced — cosine and dot product suit normalized embeddings, the geometric metrics suit raw coordinates, and Hamming suits binary codes. The engine selects the matching comparison from this tag.

Examples

use iqdb_types::DistanceMetric;

let metric = DistanceMetric::Cosine;
assert_eq!(metric, DistanceMetric::Cosine);
assert_ne!(metric, DistanceMetric::Euclidean);

The enum is #[non_exhaustive]: future releases may add metrics (for example, Jaccard or Chebyshev) without it being a breaking change, so a match on it from another crate must include a wildcard arm.

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.

Cosine

Cosine distance — the angle between vectors, ignoring magnitude. Suits normalized embeddings.

DotProduct

Dot-product similarity — magnitude-sensitive inner product. Suits embeddings where magnitude carries signal.

Euclidean

Euclidean (L2) distance — straight-line distance between coordinates.

Manhattan

Manhattan (L1) distance — sum of absolute per-component differences.

Hamming

Hamming distance — count of differing positions. Suits binary codes.

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 Copy for DistanceMetric

impl Debug for DistanceMetric

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for DistanceMetric

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for DistanceMetric

impl Hash for DistanceMetric

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

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 Serialize for DistanceMetric

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for DistanceMetric