Enum DistanceMetric 

pub enum DistanceMetric {
    Cosine,
    Euclidean,
    DotProduct,
    Manhattan,
}

Distance metric for vector similarity computation.

Different metrics are suited for different embedding types:

• Cosine: Best for normalized embeddings (most text embeddings)
• Euclidean: Best for raw embeddings where magnitude matters
• DotProduct: Best for maximum inner product search
• Manhattan: Alternative to Euclidean, less sensitive to outliers

Variants

Cosine

Cosine distance: 1 - cosine_similarity.

Range: [0, 2], where 0 = identical direction, 2 = opposite direction. Best for normalized embeddings (most text/sentence embeddings).

Euclidean

Euclidean (L2) distance: sqrt(sum((a[i] - b[i])^2)).

Range: [0, infinity), where 0 = identical vectors. Best when magnitude matters.

DotProduct

Negative dot product: -sum(a[i] * b[i]).

Returns negative so that smaller = more similar (for min-heap). Best for maximum inner product search (MIPS).

Manhattan

Manhattan (L1) distance: sum(|a[i] - b[i]|).

Range: [0, infinity), where 0 = identical vectors. Less sensitive to outliers than Euclidean.

Implementations

impl DistanceMetric

pub const fn name(&self) -> &'static str

Returns the name of the metric as a string.

pub fn from_str(s: &str) -> Option<Self>

Parses a metric from a string (case-insensitive).

Examples

use grafeo_core::index::vector::DistanceMetric;

assert_eq!(DistanceMetric::from_str("cosine"), Some(DistanceMetric::Cosine));
assert_eq!(DistanceMetric::from_str("EUCLIDEAN"), Some(DistanceMetric::Euclidean));
assert_eq!(DistanceMetric::from_str("l2"), Some(DistanceMetric::Euclidean));
assert_eq!(DistanceMetric::from_str("invalid"), None);

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 Default for DistanceMetric

fn default() -> DistanceMetric

Returns the “default value” for a type.

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 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 Copy for DistanceMetric

impl Eq for DistanceMetric

impl StructuralPartialEq for DistanceMetric