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CLAP audio-text retrieval: pinned-protocol measurement release (v15)
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"""Bootstrap confidence intervals and paired model comparisons.
Reads the per-query JSON written by `eval_clap_tf.py --per-query`, so every
number carries an interval derived from the actual queries rather than a single
point estimate.
python analysis.py results_final # writes analysis.json + prints
python analysis.py results_final --paired clotho
Bootstrap: 2000 resamples over queries, fixed seed. The paired comparison uses
the shared fixture fingerprint to guarantee both checkpoints scored the same
clip/caption sequence, then resamples queries *together* (paired bootstrap) and
reports a McNemar exact test on the discordant pairs.
"""
from __future__ import annotations
import argparse
import json
import math
from pathlib import Path
import numpy as np
SEED = 12345
N_BOOT = 2000
def _ci(values: np.ndarray, stat, n_boot: int = N_BOOT, seed: int = SEED):
"""Percentile bootstrap. Returns (low, high, standard error)."""
rng = np.random.default_rng(seed)
n = len(values)
draws = np.empty(n_boot, dtype=np.float64)
for i in range(n_boot):
idx = rng.integers(0, n, n)
draws[i] = stat(values[idx])
return (float(np.percentile(draws, 2.5)), float(np.percentile(draws, 97.5)),
float(draws.std(ddof=1)))
def cell_stats(d: dict) -> dict:
"""Recompute headline metrics from per-query arrays and bootstrap them."""
t2a, a2t = d["metrics"]["t2a"], d["metrics"]["a2t"]
tr = np.asarray(t2a["first_hit_rank"], dtype=np.int64)
ar = np.asarray(a2t["first_hit_rank"], dtype=np.int64)
aap = np.asarray(a2t["ap"], dtype=np.float64)
out = {"model": d["model"], "dataset": d["dataset"], "tag": d.get("tag"),
"audio_batch": d["protocol"]["audio_batch"],
"trim_seconds": d["protocol"]["trim_seconds"],
"fixture_fingerprint": d.get("fixture_fingerprint"),
"counts": d["counts"], "metrics": {}}
specs = [
("t2a_r1", tr, lambda v: float((v == 1).mean()), t2a["r@1"]),
("t2a_r5", tr, lambda v: float((v <= 5).mean()), t2a["r@5"]),
("t2a_r10", tr, lambda v: float((v <= 10).mean()), t2a["r@10"]),
("t2a_mrr", tr, lambda v: float((1.0 / v).mean()), t2a["map"]),
("a2t_r1", ar, lambda v: float((v == 1).mean()), a2t["r@1"]),
("a2t_r5", ar, lambda v: float((v <= 5).mean()), a2t["r@5"]),
("a2t_r10", ar, lambda v: float((v <= 10).mean()), a2t["r@10"]),
("a2t_map", aap, lambda v: float(v.mean()), a2t["map"]),
]
for name, arr, stat, reported in specs:
point = stat(arr)
lo, hi, se = _ci(arr, stat)
# the bootstrap point must reproduce the harness's own number
assert abs(point - reported) < 1e-6, (name, point, reported)
out["metrics"][name] = {"value": point, "ci95": [lo, hi], "se": se}
out["metrics"]["n_queries"] = {"t2a": int(len(tr)), "a2t": int(len(ar))}
# kept in memory for the paired tests; stripped before the JSON is written
out["_pq"] = {"t2a": tr, "a2t": ar, "a2t_ap": aap}
return out
def paired(a: dict, b: dict, metric: str = "r@1") -> dict:
"""Paired bootstrap on two cells of the same fixture, plus McNemar for hits."""
assert a["fixture_fingerprint"] == b["fixture_fingerprint"], (
"fixtures differ; paired comparison is not legitimate")
if metric.endswith("map"):
va = a["_pq"]["a2t_ap"].astype(np.float64)
vb = b["_pq"]["a2t_ap"].astype(np.float64)
n = len(va)
diff = float(vb.mean() - va.mean())
rng = np.random.default_rng(SEED)
deltas = np.empty(N_BOOT)
for i in range(N_BOOT):
idx = rng.integers(0, n, n)
deltas[i] = vb[idx].mean() - va[idx].mean()
return {"a": a["model"], "b": b["model"], "metric": metric,
"delta": diff,
"ci95": [float(np.percentile(deltas, 2.5)),
float(np.percentile(deltas, 97.5))],
"n": n, "discordant_a_only": None, "discordant_b_only": None,
"mcnemar_exact_p": None}
if metric.startswith("t2a"):
xa, xb = a["_pq"]["t2a"], b["_pq"]["t2a"]
else:
xa, xb = a["_pq"]["a2t"], b["_pq"]["a2t"]
k = int(metric.split("r@")[1])
ha, hb = xa <= k, xb <= k
n = len(ha)
diff = float(hb.mean() - ha.mean())
rng = np.random.default_rng(SEED)
deltas = np.empty(N_BOOT)
for i in range(N_BOOT):
idx = rng.integers(0, n, n)
deltas[i] = hb[idx].mean() - ha[idx].mean()
lo, hi = float(np.percentile(deltas, 2.5)), float(np.percentile(deltas, 97.5))
n01 = int((~ha & hb).sum()) # a misses, b hits
n10 = int((ha & ~hb).sum()) # a hits, b misses
m = n01 + n10
# exact two-sided binomial under p=0.5
if m == 0:
p = 1.0
else:
tail = sum(math.comb(m, i) for i in range(0, min(n01, n10) + 1)) / 2 ** m
p = min(1.0, 2 * tail)
return {"a": a["model"], "b": b["model"], "metric": metric,
"delta": diff, "ci95": [lo, hi], "n": n,
"discordant_a_only": n10, "discordant_b_only": n01,
"mcnemar_exact_p": p}
def main() -> int:
ap = argparse.ArgumentParser()
ap.add_argument("dir", nargs="?", default="results_final")
ap.add_argument("--out", default="analysis.json")
args = ap.parse_args()
files = sorted(Path(args.dir).glob("*.json"))
files = [f for f in files if "summary" not in f.name]
if not files:
print(f"no result JSONs in {args.dir}")
return 1
cells = []
for f in files:
d = json.loads(f.read_text(encoding="utf-8"))
if "first_hit_rank" not in d["metrics"]["t2a"]:
print(f"skip {f.name}: no per-query arrays (rerun with --per-query)")
continue
cells.append(cell_stats(d))
pairs = []
by_key = {}
for c in cells:
if c["audio_batch"] == 1 and c["trim_seconds"] == 10.0:
by_key.setdefault(c["dataset"], {})[c["model"]] = c
for ds, models in by_key.items():
ids = sorted(models)
if len(ids) == 2 and "clap-htsat-fused" in ids[0] + ids[1]:
a, b = models[ids[0]], models[ids[1]]
for metric in ("t2a r@1", "a2t r@1", "a2t map"):
pairs.append(paired(a, b, metric))
print(f"{'model':<28}{'ds':<10}{'metric':<10}{'value':>8} 95% CI")
for c in cells:
for k, v in c["metrics"].items():
if k == "n_queries":
continue
print(f"{c['model']:<28}{c['dataset']:<10}{k:<10}{v['value']:>8.3f} "
f"[{v['ci95'][0]:.3f}, {v['ci95'][1]:.3f}]")
if pairs:
print("\npaired comparisons (same fixture, resampled together)")
for p in pairs:
mcn = ("n/a" if p["mcnemar_exact_p"] is None
else f"{p['mcnemar_exact_p']:.3g}")
disc = ("n/a" if p["discordant_a_only"] is None
else f"{p['discordant_a_only']}/{p['discordant_b_only']}")
print(f"{p['a']} -> {p['b']} | {p['metric']}: delta {p['delta']:+.3f} "
f"[{p['ci95'][0]:+.3f}, {p['ci95'][1]:+.3f}], "
f"discordant {disc}, McNemar p={mcn}")
# per-query arrays are large and only needed in memory
slim = [{k: v for k, v in c.items() if k != "_pq"} for c in cells]
Path(args.out).write_text(
json.dumps({"cells": slim, "paired": pairs}, indent=2), encoding="utf-8")
print(f"\nwrote {args.out}")
return 0
if __name__ == "__main__":
raise SystemExit(main())