TestRandomization / code /case2 /rankstats.py
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"""Per-scenario rank rule (the same rule as Case 1), pairwise win rates, Kendall tau and goal bootstrap. Sim2Sim.
Times: array T[policy, goal, trial] in seconds, failure = HORIZON (40 s), so failures rank last and tie.
Rank rule: per (goal, trial) fractional ranks by time (1 = fastest, ties share the mean rank).
Policy score = mean rank, first over the trials of a goal, then over goals (equal goal weight).
Order = ascending mean rank. Win rate P(p beats q) = mean of 1[T_p < T_q] + 0.5 * 1[T_p == T_q].
Bootstrap resamples goals (stratified by goal range), keeps all trials of a goal, and is paired across
methods (the same goal indices for ROM methods and Chrono).
"""
import numpy as np
from scipy.stats import rankdata
from common import HORIZON_S
def bounded(times, success):
t = np.where(success, times, HORIZON_S)
return np.minimum(np.nan_to_num(t, nan=HORIZON_S), HORIZON_S)
def per_goal_ranks(T):
"""T[p, g, k] -> per-goal mean rank R[p, g] (fractional ranks within each (g, k))."""
P, G, K = T.shape
r = rankdata(T.reshape(P, -1), axis=0, method='average').reshape(P, G, K)
return r.mean(2)
def per_goal_wins(T):
"""W[p, q, g] = mean over trials of P(T_p < T_q) with ties 0.5."""
lt = (T[:, None] < T[None, :]).astype(np.float64)
eq = (T[:, None] == T[None, :]).astype(np.float64)
return (lt + 0.5 * eq).mean(3)
def kendall_tau_b(a, b):
"""Kendall tau-b between score vectors a[..., n] and b[..., n] (lower score = better; only sign matters)."""
i, j = np.triu_indices(a.shape[-1], 1)
sa = np.sign(a[..., i] - a[..., j])
sb = np.sign(b[..., i] - b[..., j])
n0 = len(i)
n1 = (sa == 0).sum(-1)
n2 = (sb == 0).sum(-1)
den = np.sqrt((n0 - n1) * (n0 - n2).astype(np.float64))
with np.errstate(invalid='ignore', divide='ignore'):
return np.where(den > 0, (sa * sb).sum(-1) / den, np.nan)
def spearman(a, b):
ra = rankdata(a, axis=-1)
rb = rankdata(b, axis=-1)
ra = ra - ra.mean(-1, keepdims=True)
rb = rb - rb.mean(-1, keepdims=True)
with np.errstate(invalid='ignore', divide='ignore'):
return (ra * rb).sum(-1) / np.sqrt((ra ** 2).sum(-1) * (rb ** 2).sum(-1))
def boot_indices(strata, B, seed):
"""strata: array of stratum labels per goal. Returns (B, G) resampled goal indices, stratified."""
rng = np.random.default_rng(seed)
strata = np.asarray(strata)
cols = []
for s in np.unique(strata):
idx = np.flatnonzero(strata == s)
cols.append(idx[rng.integers(0, len(idx), (B, len(idx)))])
return np.concatenate(cols, 1)
def ci(x, lo=2.5, hi=97.5):
x = np.asarray(x, dtype=np.float64)
x = x[np.isfinite(x)]
return [float(np.percentile(x, lo)), float(np.percentile(x, hi))] if len(x) else [None, None]
def summarize_method(T, success, policies, goal_range, boot=None):
"""Success by range, mean rank, order, resolved pairs. T and success are [p, g, k]."""
R = per_goal_ranks(T)
mr = R.mean(1)
order = [policies[i] for i in np.argsort(mr, kind='stable')]
out = dict(mean_rank={p: float(mr[i]) for i, p in enumerate(policies)}, order=order)
gr = np.asarray(goal_range)
out['success_rate'] = {rng: {p: float(success[i][gr == rng].mean()) for i, p in enumerate(policies)}
for rng in sorted(set(gr))}
out['success_rate']['all'] = {p: float(success[i].mean()) for i, p in enumerate(policies)}
# mean time over goals (and trials) where every policy succeeds
allok = success.all(0)
out['common_success_units'] = int(allok.sum())
out['mean_time_common_success'] = {p: (float(T[i][allok].mean()) if allok.any() else None) for i, p in enumerate(policies)}
if boot is not None:
W = per_goal_wins(T)
w = W.mean(2)
wb = W[:, :, boot].mean(3) # [p, q, B]
pairs = []
for a in range(len(policies)):
for b in range(a + 1, len(policies)):
lo, hi = ci(wb[a, b])
pairs.append(dict(a=policies[a], b=policies[b], win_a=float(w[a, b]), ci95=[lo, hi],
resolved=bool(lo > 0.5 or hi < 0.5)))
out['pairs'] = pairs
out['resolved_pairs'] = int(sum(p['resolved'] for p in pairs))
mrb = R[:, boot].mean(2).T # [B, p]
out['mean_rank_ci95'] = {p: ci(mrb[:, i]) for i, p in enumerate(policies)}
return out
def compare_to_truth(methods, truth, boot):
"""methods: dict name -> per-goal mean ranks R[p, g]; truth: R[p, g] (Chrono). Paired goal bootstrap."""
t_mr = truth.mean(1)
t_b = truth[:, boot].mean(2).T
res = {}
taus_b = {}
for name, R in methods.items():
mr = R.mean(1)
rb = R[:, boot].mean(2).T
tb = kendall_tau_b(rb, t_b)
taus_b[name] = tb
res[name] = dict(kendall_tau_b=float(kendall_tau_b(mr, t_mr)), kendall_ci95=ci(tb),
spearman=float(spearman(mr, t_mr)), spearman_ci95=ci(spearman(rb, t_b)))
return res, taus_b
def pair_agreement(R_method, R_base, R_truth, policies):
"""Pairs where method and base disagree on order: how many does each get right relative to truth."""
a, b, t = R_method.mean(1), R_base.mean(1), R_truth.mean(1)
i, j = np.triu_indices(len(policies), 1)
sm, sb, st = np.sign(a[i] - a[j]), np.sign(b[i] - b[j]), np.sign(t[i] - t[j])
disc = (sm != sb)
return dict(pairs=int(len(i)), method_correct=int((sm == st).sum()), base_correct=int((sb == st).sum()),
discordant=int(disc.sum()), discordant_method_correct=int((disc & (sm == st)).sum()),
discordant_base_correct=int((disc & (sb == st)).sum()))