FAILURE MAP
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FA-71576 / Seismic magnitude estimation / Open access

Clipping-aware amplitude pick: half swing · case 01

Amplitudes are double and magnitudes 0.3 high.

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

ROOT CAUSE

The peak-to-trough swing is reported without halving.

VERIFIED REPAIR

Return half the swing.

Unsuccessful approach: Floor division loses the half count of odd swings.

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)
    turn.append(samples[-1])
    best = max(abs(turn[i] - turn[i - 1]) for i in range(1, len(turn)))
    return ["ok", best]
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 2', [[-900, 200, 450], 1000], ['ok', 675.0]], ['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]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['segment 7', [[-120, 950, 200, 450], 1000], ['clipped', None]], ['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 14', [[-40, 30, 450], 1000], ['ok', 245.0]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]]], [['segment 14', [[-40, 30, 450], 1000], ['ok', 245.0]], ['segment 15', [[-900, 30, -900, 30, 0, 950, 950], 1000], ['clipped', None]], ['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]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['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 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]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]]], [['segment 28', [[-40, 200, 950, -500], 1000], ['clipped', None]], ['segment 29', [[450, 950, 950, -900, 450, 30, 950, 950, 30], 1000], ['clipped', None]], ['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]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]]]
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 2['ok', 1350]['ok', 675.0]Failed
segment 3['clipped', None]['clipped', None]Passed
segment 4['clipped', None]['clipped', None]Passed
segment 5['clipped', None]['clipped', None]Passed
segment 6['ok', 530]['ok', 265.0]Failed
end swing['ok', 395]['ok', 197.5]Failed

SHA-256 / e6ad5039fc4de7567820739e82ef189f8bea9c89b18d4eb6d6af6691fe0127fe

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[-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 2', [[-900, 200, 450], 1000], ['ok', 675.0]], ['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]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['segment 7', [[-120, 950, 200, 450], 1000], ['clipped', None]], ['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 14', [[-40, 30, 450], 1000], ['ok', 245.0]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]]], [['segment 14', [[-40, 30, 450], 1000], ['ok', 245.0]], ['segment 15', [[-900, 30, -900, 30, 0, 950, 950], 1000], ['clipped', None]], ['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]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['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 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]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]]], [['segment 28', [[-40, 200, 950, -500], 1000], ['clipped', None]], ['segment 29', [[450, 950, 950, -900, 450, 30, 950, 950, 30], 1000], ['clipped', None]], ['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]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]]]
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 2['ok', 675]['ok', 675.0]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]['ok', 265.0]Passed
end swing['ok', 197]['ok', 197.5]Failed

SHA-256 / 5f35d90907ba30b2cbd552b6473bf9dd51022cd0ef7e9dec5afab2649a6313be

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 2', [[-900, 200, 450], 1000], ['ok', 675.0]], ['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]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['segment 7', [[-120, 950, 200, 450], 1000], ['clipped', None]], ['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 14', [[-40, 30, 450], 1000], ['ok', 245.0]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]]], [['segment 14', [[-40, 30, 450], 1000], ['ok', 245.0]], ['segment 15', [[-900, 30, -900, 30, 0, 950, 950], 1000], ['clipped', None]], ['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]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]], [['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 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]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]]], [['segment 28', [[-40, 200, 950, -500], 1000], ['clipped', None]], ['segment 29', [[450, 950, 950, -900, 450, 30, 950, 950, 30], 1000], ['clipped', None]], ['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]], ['odd swing', [[0, 101, 0, 50], 1000], ['ok', 50.5]], ['end swing', [[0, 10, 5, 400], 1000], ['ok', 197.5]]]]
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 2['ok', 675.0]['ok', 675.0]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
end swing['ok', 197.5]['ok', 197.5]Passed

SHA-256 / 1d9cbe043539803f2438c1329a69019eb110f2e98ac0dd9937d847f1b4311977

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 2026-09-29T14:48:30.923786+00:00.

Case digest / 5dc4b22eddb6ecccc4088eaee59dc064aefb0f4b1011529755a9727953942fb5