Struct FibMultiLevelQuantizer 

pub struct FibMultiLevelQuantizer { /* private fields */ }

Multi-level additive quantizer: main codebook + N trained residual codebooks.

Each residual level is trained with Lloyd-Max on the residual distribution from the previous levels, producing codebooks adapted to the actual data rather than random directions.

num_levels = 1 means main only (no residual codebooks). num_levels = 2 means main + 1 residual level (equivalent to 2-level). num_levels = 3 means main + 2 residual levels.

Implementations

impl FibMultiLevelQuantizer

pub fn new( profile: FibQuantProfileV1, num_levels: usize, residual_sizes: Vec<usize>, ) -> Result<Self>

Build a multi-level quantizer with trained residual codebooks.

Arguments

• profile - The quantization profile.
• num_levels - Total number of levels (1 = main only, 2 = main + 1 residual, etc.).
• residual_sizes - Number of codewords for each residual level (length must be num_levels - 1).

pub fn quantizer(&self) -> &FibQuantizer

Access the main quantizer.

pub fn residual_codebooks(&self) -> &[ResidualCodebookV1]

Access all residual codebooks.

pub fn num_levels(&self) -> usize

Total number of levels (1 + residual codebooks count).

pub fn multi_level_codebook(&self) -> MultiLevelResidualCodebookV1

Get a MultiLevelResidualCodebookV1 view of the residual codebooks.

pub fn encode(&self, x: &[f32]) -> Result<MultiLevelCode>

Encode a vector with multi-level additive quantization.

Encodes with the main codebook, then iteratively encodes the residual with each residual level: residual[i+1] = residual[i] - cw_i[idx_i].

pub fn decode(&self, code: &MultiLevelCode) -> Result<Vec<f32>>

Decode a multi-level code.

Reconstructs: codeword[main] + residual_cw[0] + residual_cw[1] + … then applies inverse rotation and norm scaling.

pub fn cosine_similarity(&self, x: &[f32]) -> Result<f64>

Reconstruction cosine similarity.

Trait Implementations

impl Clone for FibMultiLevelQuantizer

fn clone(&self) -> FibMultiLevelQuantizer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FibMultiLevelQuantizer

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

Formats the value using the given formatter.