Files
Marius CiepluchandClaude Fable 5.1 c95b9241d8 feat(stats): one statistics module on scipy, statsmodels and scikit-learn; engineered features tied to the annotations
openultrasast.stats: Wilson intervals (statsmodels), exact McNemar, a
repository-clustered percentile bootstrap and its paired form with one
quantile convention, grouped folds (GroupKFold, leave-one-group-out), and
per-column separation (ROC AUC) for the leak audit and the signal screen.
Checked against the benchmark scorer's Wilson and the learn harness's
McNemar. hunt/features.py turns the feature table into the engineered
frame (distances, counts, flags) and keeps the map from every engineered
feature to the annotation the model is shown, so an ablation mask drops
both, and screen() says which annotation carries signal before a model
call is spent. The [hunt] extra now carries the libraries; the core
install is unchanged. The learn harness's own copies stay until that line
is revived.

Co-Authored-By: Claude Fable 5.1 <[email protected]>
2026-10-13 12:43:02 +02:00

105 lines
4.1 KiB
Python

"""The shared statistics against the formulas the benchmark and the learn harness used."""
from __future__ import annotations
import math
import pytest
pd = pytest.importorskip("pandas")
pytest.importorskip("statsmodels")
pytest.importorskip("sklearn")
from openultrasast import stats # noqa: E402
def test_wilson_matches_the_benchmark_scorer_to_three_decimals():
from benchmarks.unseen.score import wilson as scorer_wilson
for successes, n in ((6, 12), (5, 12), (130, 239), (1, 149), (0, 12), (221, 239)):
low, high = stats.wilson(successes, n)
old_low, old_high = scorer_wilson(successes, n)
assert abs(low - old_low) < 1e-3 and abs(high - old_high) < 1e-3, (successes, n)
assert stats.wilson(0, 0) is None
low, high = stats.wilson(6, 12)
assert round(low, 3) == 0.254 and round(high, 3) == 0.746 # the pilot's hunter recall interval
def test_exact_mcnemar_matches_the_learn_harness():
import random
from openultrasast.learn.experiments import exact_mcnemar
rng = random.Random(1)
for _ in range(20):
n = rng.randint(1, 40)
a = [rng.random() < 0.5 for _ in range(n)]
b = [rng.random() < 0.5 for _ in range(n)]
ours = stats.mcnemar_exact(a, b)
theirs = exact_mcnemar(list(zip(a, b, strict=True)))
assert (ours.b, ours.c, ours.concordant) == (theirs.b, theirs.c, theirs.concordant)
assert math.isclose(ours.p_value, theirs.p_value, abs_tol=1e-9), (a, b)
assert stats.mcnemar_exact([True, False], [True, False]).p_value == 1.0
with pytest.raises(ValueError):
stats.mcnemar_exact([True], [True, False])
def _frame(seed=0, groups=8, per=6):
import numpy as np
rng = np.random.default_rng(seed)
rows = []
for g in range(groups):
for _ in range(per):
a = rng.random() < 0.4
rows.append({"repo": f"r{g}", "a": int(a), "b": int(a or rng.random() < 0.3), "label": int(rng.random() < 0.5)})
return pd.DataFrame(rows)
def test_cluster_bootstrap_is_seeded_and_brackets_the_estimate():
frame = _frame()
stat = lambda f: float(f["a"].mean()) # noqa: E731
first = stats.cluster_bootstrap(frame, "repo", stat, resamples=300, seed=3)
second = stats.cluster_bootstrap(frame, "repo", stat, resamples=300, seed=3)
assert first == second and first[0] <= stat(frame) <= first[1]
assert stats.cluster_bootstrap(frame.iloc[0:0], "repo", stat) is None
def test_paired_bootstrap_reports_b_minus_a_with_an_interval():
frame = _frame()
estimate = stats.paired_bootstrap(frame, "repo", "a", "b", resamples=300, seed=1)
assert estimate.diff == pytest.approx(frame["b"].mean() - frame["a"].mean())
assert estimate.ci is not None and estimate.ci[0] <= estimate.diff <= estimate.ci[1]
assert estimate.units == len(frame) and estimate.groups == 8 and estimate.resamples == 300
assert estimate.se is not None and estimate.se > 0
def test_group_folds_never_split_a_repository():
frame = _frame(groups=10)
folds = stats.group_folds(frame, "repo", k=5, seed=0)
assert len(folds) == 5
for train, test in folds:
assert not set(frame.iloc[train]["repo"]) & set(frame.iloc[test]["repo"])
assert sorted(train + test) == list(range(len(frame)))
assert len(stats.leave_one_group_out(frame, "repo")) == 10
with pytest.raises(ValueError):
stats.group_folds(_frame(groups=3), "repo", k=5)
def test_separation_scores_each_column_alone():
frame = pd.DataFrame(
{
"label": [1, 1, 1, 0, 0, 0, None],
"perfect": [5, 6, 7, 1, 2, 3, 9],
"noise": [1, 1, 1, 1, 1, 1, 1],
"inverse": [1, 2, 3, 5, 6, 7, 0],
"sparse": [None, None, None, None, None, None, 1],
}
)
out = stats.separation(frame, "label", ["perfect", "noise", "inverse", "sparse", "missing"]).set_index("column")
assert out.loc["perfect", "auc"] == 1.0 and out.loc["perfect", "n"] == 6
assert out.loc["inverse", "auc"] == 0.0
assert out.loc["noise", "auc"] == 0.5 and out.loc["noise", "note"] == "constant"
assert out.loc["sparse", "auc"] is None or pd.isna(out.loc["sparse", "auc"])
assert out.loc["missing", "note"] == "missing"