Function l2_sub

nodedb-vector/src/quantize/pq.rs:261–268

(a: &[f32], b: &[f32])

/// L2 squared distance for sub-vectors (used in k-means and encoding).
#[inline]
fn l2_sub(a: &[f32], b: &[f32]) -> f32 {
    let mut sum = 0.0f32;
    for i in 0..a.len() {
        let d = a[i] - b[i];
        sum += d * d;
    }
    sum
}

/// Simple k-means clustering for PQ codebook training.
///