Function quantize_dequantize_roundtrip

nodedb-vector/src/quantize/sq8.rs:284–303

()

    #[test]
    fn quantize_dequantize_roundtrip() {
        let vecs = make_vectors();
        let refs: Vec<&[f32]> = vecs.iter().map(|v| v.as_slice()).collect();
        let codec = Sq8Codec::calibrate(&refs, 3);

        for v in &vecs {
            let q = codec.quantize(v);
            let dq = codec.dequantize(&q);
            for d in 0..3 {
                let error = (v[d] - dq[d]).abs();
                let range = codec.maxs[d] - codec.mins[d];
                // Error should be at most half a quantization step.
                assert!(
                    error <= range / 255.0 + 1e-6,
                    "d={d}: error={error}, max_step={}",
                    range / 255.0
                );
            }
        }
    }

    #[test]
    fn asymmetric_l2_close_to_exact() {