← Lab
ropeprecision
confirmedRustSystems & data structuresJuly 6, 2026
the question
Does RoPE rotary positional encoding lose precision at long context?
what came out
Yes -- naive f32 error grows linearly with position (~3e-3 at 128k tokens). Reducing the angle mod 2pi in f64 fixes it entirely (>10000x better). Rust, f64 oracle, pre-registered.
method & receipts
- Result: confirmed
- Pre-registered — the prediction was written down and committed before the run.
- Reproducible — one script re-runs the whole thing from scratch.
- Independently reviewed — an adversarial review pass, kept in the repo.
- Machine-readable claims — every reported number, in a checkable file.
→ read the code and re-run it
github.com/v-code01/ropeprecision