Struct FourBitQuantizer 

pub struct FourBitQuantizer { /* private fields */ }

4-bit quantizer for balanced memory/accuracy trade-off (8x compression)

Converts float32 vectors to 4-bit (16 levels) by per-dimension min-max scaling. Packs two 4-bit values into each u8 byte (high and low nibbles).

Implementations

impl FourBitQuantizer

pub fn new() -> Self

Create a new 4-bit quantizer

pub fn fit(&mut self, vectors: &[Vec<f32>]) -> Result<()>

Fit quantizer to training data

Computes per-dimension min/max values for 4-bit quantization.

pub fn quantize(&self, vector: &[f32]) -> Vec<u8>

Quantize a float32 vector to 4-bit (packed as u8 array)

Two 4-bit values are packed into each u8: high nibble (bits 4-7) and low nibble (bits 0-3).

pub fn dequantize(&self, quantized: &[u8]) -> Vec<f32>

Dequantize a 4-bit vector back to float32

pub fn quantize_batch(&self, vectors: &[Vec<f32>]) -> Vec<Vec<u8>>

Quantize multiple vectors

pub fn dequantize_batch(&self, quantized: &[Vec<u8>]) -> Vec<Vec<f32>>

Dequantize multiple vectors

pub fn quantized_distance(&self, a: &[u8], b: &[u8]) -> f32

Compute approximate distance between 4-bit quantized vectors

Uses Manhattan distance on nibble values for speed.

pub fn compression_ratio(&self) -> f32

Get compression ratio

pub fn memory_savings(&self) -> f32

Get memory savings percentage

pub fn is_fitted(&self) -> bool

Check if quantizer is fitted

pub fn dimensions(&self) -> usize

Get number of dimensions

Trait Implementations

impl Clone for FourBitQuantizer

fn clone(&self) -> FourBitQuantizer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FourBitQuantizer

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

Formats the value using the given formatter.

impl Default for FourBitQuantizer

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for FourBitQuantizer

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for FourBitQuantizer

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

where __S: Serializer,

Serialize this value into the given Serde serializer.