Struct PQConfig 

pub struct PQConfig {
    pub dim: usize,
    pub num_subspaces: usize,
    pub dims_per_block: usize,
    pub num_centroids: usize,
    pub seed: u64,
    pub anisotropic: bool,
    pub aniso_eta: f32,
    pub aniso_threshold: f32,
    pub use_opq: bool,
    pub opq_iters: usize,
}

Configuration for Product Quantization with OPQ and Anisotropic Loss

Fields

dim: usize

Vector dimension

num_subspaces: usize

Number of subspaces (M) - computed from dim / dims_per_block

dims_per_block: usize

Dimensions per subspace block (ScaNN recommends 2)

num_centroids: usize

Number of centroids per subspace (K) - typically 256 for u8 codes

seed: u64

Random seed for reproducibility

anisotropic: bool

Use anisotropic quantization (true ScaNN-style parallel/orthogonal weighting)

aniso_eta: f32

Anisotropic eta: ratio of parallel to orthogonal error weight (η)

aniso_threshold: f32

Anisotropic threshold T: only consider inner products >= T

use_opq: bool

Use OPQ rotation matrix (learned via SVD)

opq_iters: usize

Number of OPQ iterations

Implementations

impl PQConfig

pub fn new(dim: usize) -> Self

Create config with ScaNN-recommended defaults

pub fn new_fast(dim: usize) -> Self

Create config with larger subspaces (faster but less accurate)

pub fn new_balanced(dim: usize) -> Self

Create balanced config (good recall/speed tradeoff) Uses 16 subspaces for 128D+ vectors, 8 for smaller

pub fn with_dims_per_block(self, d: usize) -> Self

pub fn with_subspaces(self, m: usize) -> Self

pub fn with_centroids(self, k: usize) -> Self

pub fn with_anisotropic(self, enabled: bool, eta: f32) -> Self

pub fn with_opq(self, enabled: bool, iters: usize) -> Self

pub fn subspace_dim(&self) -> usize

Dimension of each subspace

Trait Implementations

impl Clone for PQConfig

fn clone(&self) -> PQConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PQConfig

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for PQConfig

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for PQConfig

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

where __S: Serializer,

Serialize this value into the given Serde serializer.