Files
esh-pfi-infrastructure/scripts/r49-corpus/build_beat_fixture.py
T
vh e9e8c40b83 eval harness: sample the beat fixture from held-out val, and bind the eval prompt to the trained one
Two harness defects that would each make a voice number uninterpretable.

build_beat_fixture.py — the fixture is now SAMPLED from the val split rather than
hand-written. The original BabyYarros fixture was five hand-written beats about a
stray dog and a kitten: wrong genre, so 'He licked her clean' came back as
explicit sex from a romantasy adapter, and n=5 had a noise floor of 0.800 that
manufactured a +0.45 result which collapsed to +0.08 at n=120. Sampling from val
makes it in-genre and held out by construction, spread across works so a naive
head(30) is not one novel. Refuses outright if the pairs carry any split but val,
because a fixture drawn from training data makes every downstream number a
memorisation measurement wearing a voice label.

gen_beats_chat_yarros.py --system-from — the SYS constant in this harness is
Yarros's. Driving a Bronte or Hemingway adapter with it measures the arm under a
system prompt it was never trained on and confounds the carrier change with a
prompt change. Rather than duplicate the register table and rely on whoever runs
it to pick the matching one, read the prompt out of the pair build's own
provenance, which is the artefact that records what the adapter actually saw.
2026-09-16 21:18:44 -07:00

94 lines
4.1 KiB
Python

"""Build the N-beat evaluation fixture from HELD-OUT val pairs.
⚠ THE FIXTURE MUST BE IN-GENRE, AND THAT IS NOT A STYLE PREFERENCE. The first
BabyYarros fixture was five hand-written beats about a stray dog and a kitten.
Two things went wrong and both were invisible until measured:
* WRONG GENRE. `He licked her clean, and would not be driven off` came back as
explicit sex from an adapter trained on romantasy. A beat that never occurs in
the training distribution measures the carrier's priors, not the voice.
* n=5 HAS NO RESOLUTION. That fixture's noise floor was 0.800 and it manufactured
a +0.45 in-band "result" which collapsed to +0.08 — inside a 0.233 floor — at
n=120. One sample moves a rate by 0.2 when there are five.
So the fixture is SAMPLED from the val split the adapter never trained on: in-genre
by construction, held out by construction, and large enough that the per-arm sample
(N beats x S seeds) can resolve something. Nothing here is hand-written.
Emits the `[{"id","beat"}]` shape gen_beats_chat_*.py reads, plus a sidecar keeping
each beat's true held-out response so a memorisation check has its reference text.
"""
from __future__ import annotations
import argparse, json, random
from pathlib import Path
def main() -> int:
ap = argparse.ArgumentParser()
ap.add_argument("--pairs", required=True, help="held-out val pairs jsonl")
ap.add_argument("--out", required=True)
ap.add_argument("--sidecar", default=None,
help="write {id, beat, response, work, chapter} here for memorisation checks")
ap.add_argument("-n", type=int, default=30)
ap.add_argument("--seed", type=int, default=4919)
ap.add_argument("--min-words", type=int, default=90,
help="skip val passages outside the product band; a 40-word reference "
"cannot tell an in-band arm from a truncated one")
ap.add_argument("--max-words", type=int, default=150)
a = ap.parse_args()
rows = [json.loads(l) for l in Path(a.pairs).read_text(encoding="utf-8").splitlines() if l.strip()]
if not rows:
print(f"== {a.pairs} is empty"); return 1
split = {r.get("split") for r in rows}
if split - {"val"}:
# Sampling the fixture from anything the adapter trained on makes every
# downstream number a memorisation measurement wearing a voice label.
print(f"== REFUSING: pairs carry split(s) {sorted(split)}; the fixture must be val-only")
return 1
band = [r for r in rows if a.min_words <= r.get("words", 0) <= a.max_words]
if len(band) < a.n:
print(f"== only {len(band)} val pairs inside {a.min_words}-{a.max_words} words, need {a.n}")
return 1
# Spread across works rather than taking a block: the val split is emitted in
# corpus order, so a naive head(30) would be one novel and one register.
by_work: dict[str, list] = {}
for r in band:
by_work.setdefault(r["work"], []).append(r)
rng = random.Random(a.seed)
for v in by_work.values():
rng.shuffle(v)
picked, works = [], sorted(by_work)
i = 0
while len(picked) < a.n:
w = works[i % len(works)]
if by_work[w]:
picked.append(by_work[w].pop())
elif not any(by_work.values()):
break
i += 1
fixture = [{"id": f"b{n+1}", "beat": r["beat"]} for n, r in enumerate(picked)]
Path(a.out).write_text(json.dumps(fixture, ensure_ascii=False, indent=1), encoding="utf-8")
if a.sidecar:
side = [{"id": f"b{n+1}", "beat": r["beat"], "response": r["response"],
"work": r["work"], "chapter": r.get("chapter"), "words": r.get("words")}
for n, r in enumerate(picked)]
Path(a.sidecar).write_text(json.dumps(side, ensure_ascii=False, indent=1), encoding="utf-8")
dist: dict[str, int] = {}
for r in picked:
dist[r["work"]] = dist.get(r["work"], 0) + 1
print(f" {len(fixture)} beats from {len(band)} in-band val pairs · per work: {dist}")
print(f" wrote {a.out}" + (f" + {a.sidecar}" if a.sidecar else ""))
return 0
if __name__ == "__main__":
raise SystemExit(main())