Function quantize

nodedb-codec/src/vector_quant/ternary/packing.rs:108–121

Quantize a FP32 vector to ternary trits using BitNet absmean scaling. Returns `(trits, scale)` where `scale = mean(|v_i|)`.

(v: &[f32])

///
/// Returns `(trits, scale)` where `scale = mean(|v_i|)`.
pub fn quantize(v: &[f32]) -> (Vec<i8>, f32) {
    if v.is_empty() {
        return (Vec::new(), 0.0);
    }
    let scale: f32 = v.iter().map(|x| x.abs()).sum::<f32>() / v.len() as f32;
    let trits = if scale == 0.0 {
        vec![0i8; v.len()]
    } else {
        v.iter()
            .map(|&x| (x / scale).round().clamp(-1.0, 1.0) as i8)
            .collect()
    };
    (trits, scale)
}

#[cfg(test)]
mod tests {