FAILURE MAP
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FA-71586 / Seismic magnitude estimation / Open access

Clipping-aware amplitude pick: final sample turning point · case 01

A swing that ends at the window edge is missed.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The last sample is not added as a turning point.

VERIFIED REPAIR

Append the last sample after the interior scan.

Unsuccessful approach: Appending the penultimate sample still omits the final excursion.

Case contract

Integer counts. If any |sample| >= 0.95*full_scale (integer-truncated) return ["clipped", None]. Otherwise turning points are the first sample, every interior sample that is a peak (b > a and b >= c) or trough (b < a and b <= c), and the last sample; the amplitude is half the largest absolute difference between consecutive turning points. Return ["ok", amplitude].

Why this case matters

Magnitude amplitudes must not come from clipped records and use half peak-to-trough swings.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(samples, full_scale):
    limit = int(full_scale * 0.95)
    if any(abs(s) >= limit for s in samples):
        return ["clipped", None]
    turn = [samples[0]]
    for i in range(1, len(samples) - 1):
        a, b, c = samples[i - 1], samples[i], samples[i + 1]
        if (b > a and b >= c) or (b < a and b <= c):
            turn.append(b)
    best = max(abs(turn[i] - turn[i - 1]) for i in range(1, len(turn)))
    return ["ok", best / 2]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['segment 0', [[30, -120, 1000], 1000], ['clipped', None]], ['segment 1', [[-500, 30, 1000, 1000, 1000, 200, 450], 1000], ['clipped', None]], ['segment 3', [[-120, 0, -120, -900, 200, -900, 1000, 200], 1000], ['clipped', None]], ['segment 4', [[30, -120, 1000, 1000, -120, 1000], 1000], ['clipped', None]], ['segment 5', [[1000, 1000, -900], 1000], ['clipped', None]], ['segment 6', [[30, -40, 30, -500], 1000], ['ok', 265.0]], ['segment 7', [[-120, 950, 200, 450], 1000], ['clipped', None]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]]], [['segment 8', [[1000, 200, 450, -120], 1000], ['clipped', None]], ['segment 9', [[-120, 1000, -40, -120, 450], 1000], ['clipped', None]], ['segment 10', [[200, 1000, -40], 1000], ['clipped', None]], ['segment 11', [[1000, 450, -900, 0, 1000], 1000], ['clipped', None]], ['segment 12', [[950, 0, 1000], 1000], ['clipped', None]], ['segment 13', [[30, -120, -120, 0, 30, 450, -120], 1000], ['ok', 285.0]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 25', [[-120, -500, -500, 30], 1000], ['ok', 265.0]]], [['segment 16', [[-900, -500, -500], 1000], ['ok', 200.0]], ['segment 17', [[-500, -120, 1000, -120], 1000], ['clipped', None]], ['segment 18', [[950, -40, 450], 1000], ['clipped', None]], ['segment 19', [[-500, 30, -500, 200, -120], 1000], ['ok', 350.0]], ['segment 20', [[-40, 30, 0, 30, 450, 450], 1000], ['ok', 225.0]], ['segment 21', [[1000, -900, 200, -120, 1000, 1000, 200], 1000], ['clipped', None]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]]], [['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]], ['segment 24', [[30, -500, 450, 30, -40], 1000], ['ok', 475.0]], ['segment 25', [[-120, -500, -500, 30], 1000], ['ok', 265.0]], ['segment 26', [[1000, 1000, 0, 30, 0, 30, -120, -900, -900], 1000], ['clipped', None]], ['segment 27', [[0, 200, 30, -500, -500, 1000, 450, -120], 1000], ['clipped', None]], ['segment 28', [[-40, 200, 950, -500], 1000], ['clipped', None]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]], ['segment 30', [[-40, 30, -40, 1000, -900, 950, 30, 1000, -500], 1000], ['clipped', None]], ['segment 31', [[200, -900, -120, -500, -120, 950, -500, 30, 450], 1000], ['clipped', None]], ['segment 32', [[-900, 950, 450, 30, 450], 1000], ['clipped', None]], ['segment 33', [[0, 30, 1000, 30, -900], 1000], ['clipped', None]], ['exactly at clip threshold', [[0, 950, -100, 20], 1000], ['clipped', None]], ['plateau peak', [[0, 300, 300, -100, 0], 1000], ['ok', 200.0]]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
segment 0['clipped', None]['clipped', None]Passed
segment 1['clipped', None]['clipped', None]Passed
segment 3['clipped', None]['clipped', None]Passed
segment 4['clipped', None]['clipped', None]Passed
segment 5['clipped', None]['clipped', None]Passed
segment 6['ok', 35.0]['ok', 265.0]Failed
segment 7['clipped', None]['clipped', None]Passed
segment 22['ok', 200.0]['ok', 430.0]Failed

SHA-256 / 39d6884afb73a1fbe12767517896f50ca9303871dbd73aaabebcce77ef16c96b

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(samples, full_scale):
    limit = int(full_scale * 0.95)
    if any(abs(s) >= limit for s in samples):
        return ["clipped", None]
    turn = [samples[0]]
    for i in range(1, len(samples) - 1):
        a, b, c = samples[i - 1], samples[i], samples[i + 1]
        if (b > a and b >= c) or (b < a and b <= c):
            turn.append(b)
    turn.append(samples[-2])
    best = max(abs(turn[i] - turn[i - 1]) for i in range(1, len(turn)))
    return ["ok", best / 2]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['segment 0', [[30, -120, 1000], 1000], ['clipped', None]], ['segment 1', [[-500, 30, 1000, 1000, 1000, 200, 450], 1000], ['clipped', None]], ['segment 3', [[-120, 0, -120, -900, 200, -900, 1000, 200], 1000], ['clipped', None]], ['segment 4', [[30, -120, 1000, 1000, -120, 1000], 1000], ['clipped', None]], ['segment 5', [[1000, 1000, -900], 1000], ['clipped', None]], ['segment 6', [[30, -40, 30, -500], 1000], ['ok', 265.0]], ['segment 7', [[-120, 950, 200, 450], 1000], ['clipped', None]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]]], [['segment 8', [[1000, 200, 450, -120], 1000], ['clipped', None]], ['segment 9', [[-120, 1000, -40, -120, 450], 1000], ['clipped', None]], ['segment 10', [[200, 1000, -40], 1000], ['clipped', None]], ['segment 11', [[1000, 450, -900, 0, 1000], 1000], ['clipped', None]], ['segment 12', [[950, 0, 1000], 1000], ['clipped', None]], ['segment 13', [[30, -120, -120, 0, 30, 450, -120], 1000], ['ok', 285.0]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 25', [[-120, -500, -500, 30], 1000], ['ok', 265.0]]], [['segment 16', [[-900, -500, -500], 1000], ['ok', 200.0]], ['segment 17', [[-500, -120, 1000, -120], 1000], ['clipped', None]], ['segment 18', [[950, -40, 450], 1000], ['clipped', None]], ['segment 19', [[-500, 30, -500, 200, -120], 1000], ['ok', 350.0]], ['segment 20', [[-40, 30, 0, 30, 450, 450], 1000], ['ok', 225.0]], ['segment 21', [[1000, -900, 200, -120, 1000, 1000, 200], 1000], ['clipped', None]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]]], [['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]], ['segment 24', [[30, -500, 450, 30, -40], 1000], ['ok', 475.0]], ['segment 25', [[-120, -500, -500, 30], 1000], ['ok', 265.0]], ['segment 26', [[1000, 1000, 0, 30, 0, 30, -120, -900, -900], 1000], ['clipped', None]], ['segment 27', [[0, 200, 30, -500, -500, 1000, 450, -120], 1000], ['clipped', None]], ['segment 28', [[-40, 200, 950, -500], 1000], ['clipped', None]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]], ['segment 30', [[-40, 30, -40, 1000, -900, 950, 30, 1000, -500], 1000], ['clipped', None]], ['segment 31', [[200, -900, -120, -500, -120, 950, -500, 30, 450], 1000], ['clipped', None]], ['segment 32', [[-900, 950, 450, 30, 450], 1000], ['clipped', None]], ['segment 33', [[0, 30, 1000, 30, -900], 1000], ['clipped', None]], ['exactly at clip threshold', [[0, 950, -100, 20], 1000], ['clipped', None]], ['plateau peak', [[0, 300, 300, -100, 0], 1000], ['ok', 200.0]]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
segment 0['clipped', None]['clipped', None]Passed
segment 1['clipped', None]['clipped', None]Passed
segment 3['clipped', None]['clipped', None]Passed
segment 4['clipped', None]['clipped', None]Passed
segment 5['clipped', None]['clipped', None]Passed
segment 6['ok', 35.0]['ok', 265.0]Failed
segment 7['clipped', None]['clipped', None]Passed
segment 22['ok', 200.0]['ok', 430.0]Failed

SHA-256 / a7536130519dc8f074fe4fb1d8339048e8642e7fca781ac59fb32cff391c4ae4

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(samples, full_scale):
    limit = int(full_scale * 0.95)
    if any(abs(s) >= limit for s in samples):
        return ["clipped", None]
    turn = [samples[0]]
    for i in range(1, len(samples) - 1):
        a, b, c = samples[i - 1], samples[i], samples[i + 1]
        if (b > a and b >= c) or (b < a and b <= c):
            turn.append(b)
    turn.append(samples[-1])
    best = max(abs(turn[i] - turn[i - 1]) for i in range(1, len(turn)))
    return ["ok", best / 2]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['segment 0', [[30, -120, 1000], 1000], ['clipped', None]], ['segment 1', [[-500, 30, 1000, 1000, 1000, 200, 450], 1000], ['clipped', None]], ['segment 3', [[-120, 0, -120, -900, 200, -900, 1000, 200], 1000], ['clipped', None]], ['segment 4', [[30, -120, 1000, 1000, -120, 1000], 1000], ['clipped', None]], ['segment 5', [[1000, 1000, -900], 1000], ['clipped', None]], ['segment 6', [[30, -40, 30, -500], 1000], ['ok', 265.0]], ['segment 7', [[-120, 950, 200, 450], 1000], ['clipped', None]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]]], [['segment 8', [[1000, 200, 450, -120], 1000], ['clipped', None]], ['segment 9', [[-120, 1000, -40, -120, 450], 1000], ['clipped', None]], ['segment 10', [[200, 1000, -40], 1000], ['clipped', None]], ['segment 11', [[1000, 450, -900, 0, 1000], 1000], ['clipped', None]], ['segment 12', [[950, 0, 1000], 1000], ['clipped', None]], ['segment 13', [[30, -120, -120, 0, 30, 450, -120], 1000], ['ok', 285.0]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 25', [[-120, -500, -500, 30], 1000], ['ok', 265.0]]], [['segment 16', [[-900, -500, -500], 1000], ['ok', 200.0]], ['segment 17', [[-500, -120, 1000, -120], 1000], ['clipped', None]], ['segment 18', [[950, -40, 450], 1000], ['clipped', None]], ['segment 19', [[-500, 30, -500, 200, -120], 1000], ['ok', 350.0]], ['segment 20', [[-40, 30, 0, 30, 450, 450], 1000], ['ok', 225.0]], ['segment 21', [[1000, -900, 200, -120, 1000, 1000, 200], 1000], ['clipped', None]], ['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]]], [['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]], ['segment 24', [[30, -500, 450, 30, -40], 1000], ['ok', 475.0]], ['segment 25', [[-120, -500, -500, 30], 1000], ['ok', 265.0]], ['segment 26', [[1000, 1000, 0, 30, 0, 30, -120, -900, -900], 1000], ['clipped', None]], ['segment 27', [[0, 200, 30, -500, -500, 1000, 450, -120], 1000], ['clipped', None]], ['segment 28', [[-40, 200, 950, -500], 1000], ['clipped', None]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['segment 22', [[-500, -900, -40], 1000], ['ok', 430.0]], ['segment 23', [[30, 0, 450, 450, 450, -900], 1000], ['ok', 675.0]], ['segment 30', [[-40, 30, -40, 1000, -900, 950, 30, 1000, -500], 1000], ['clipped', None]], ['segment 31', [[200, -900, -120, -500, -120, 950, -500, 30, 450], 1000], ['clipped', None]], ['segment 32', [[-900, 950, 450, 30, 450], 1000], ['clipped', None]], ['segment 33', [[0, 30, 1000, 30, -900], 1000], ['clipped', None]], ['exactly at clip threshold', [[0, 950, -100, 20], 1000], ['clipped', None]], ['plateau peak', [[0, 300, 300, -100, 0], 1000], ['ok', 200.0]]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
segment 0['clipped', None]['clipped', None]Passed
segment 1['clipped', None]['clipped', None]Passed
segment 3['clipped', None]['clipped', None]Passed
segment 4['clipped', None]['clipped', None]Passed
segment 5['clipped', None]['clipped', None]Passed
segment 6['ok', 265.0]['ok', 265.0]Passed
segment 7['clipped', None]['clipped', None]Passed
segment 22['ok', 430.0]['ok', 430.0]Passed

SHA-256 / 959196d8f777778f84128cffcc8c803d00d1eee0b5ea01321722505c9dd29b69

Verification & scope

Stipulated deterministic teaching model of a seismological magnitude procedure; constants and tables are fixed by the contract and no claim of agency or standards conformance is made. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:48:31.004404+00:00.

Case digest / 35bc29d6b81caeef1df95adf209990c38812bd265d7954d40399a868fb853206