Method calibrate

nodedb-codec/src/vector_quant/rabitq.rs:140–160

Calibrate a new codec from a set of training vectors. - Computes the centroid as the coordinate-wise mean of `vectors`. - Stores `rotation_seed` for reproducible signed-diagonal generation. # Errors (none — returns Self directly) Returns a zero-centroid codec if `vectors` is empty.

(vectors: &[&[f32]], dim: usize, rotation_seed: u64)

    ///
    /// Returns a zero-centroid codec if `vectors` is empty.
    pub fn calibrate(vectors: &[&[f32]], dim: usize, rotation_seed: u64) -> Self {
        let centroid = if vectors.is_empty() {
            vec![0.0f32; dim]
        } else {
            let n = vectors.len() as f32;
            let mut c = vec![0.0f32; dim];
            for v in vectors {
                for (ci, &vi) in c.iter_mut().zip(v.iter()) {
                    *ci += vi;
                }
            }
            c.iter_mut().for_each(|x| *x /= n);
            c
        };
        Self {
            dim,
            centroid,
            rotation_seed,
            bias_correct: false,
        }
    }

    /// On-disk magic for RaBitQ codec envelopes.
    pub const ENVELOPE_MAGIC: &'static [u8; codec_envelope::MAGIC_LEN] = b"NDRBQ";