Function matvec

nodedb-codec/src/vector_quant/opq.rs:201–208

(r: &[f32], v: &[f32], dim: usize)

/// Row-major matrix-vector multiply: returns R · v.
#[inline]
fn matvec(r: &[f32], v: &[f32], dim: usize) -> Vec<f32> {
    let mut out = vec![0.0f32; dim];
    for i in 0..dim {
        let row = &r[i * dim..(i + 1) * dim];
        out[i] = row.iter().zip(v.iter()).map(|(a, b)| a * b).sum();
    }
    out
}

fn pq_encode(v: &[f32], codebooks: &[Vec<Vec<f32>>], m: usize, sub_dim: usize) -> Vec<u8> {
    let mut codes = Vec::with_capacity(m);