FA-71476 / Seismic magnitude estimation / Open access

Coda duration magnitude: coda termination level · case 01

Coda end is delayed when the envelope settles exactly at twice the noise.

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

ROOT CAUSE

The termination test excludes amplitude equal to twice the noise.

VERIFIED REPAIR

End at amplitude <= 2*noise.

Unsuccessful approach: Using 1x noise extends the coda into the noise floor.

Case contract

envelope is a list of amplitude samples, dt s per sample, p_index the P pick sample, noise the pre-event noise level. From the peak at or after the pick (first maximum), the coda ends at the first sample with amplitude <= 2*noise. tau = (end - p_index)*dt; Md = -0.87 + 2.0 log10(tau) + 0.0035 epi_km. Return [tau rounded 0.01, Md rounded 0.01] or None when no end or tau <= 0.

Why this case matters

Duration magnitude is robust for small events with clipped or noisy amplitudes.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(envelope, dt, p_index, noise, epi_km):
    if p_index >= len(envelope):
        return None
    peak = max(range(p_index, len(envelope)), key=lambda i: envelope[i])
    end = None
    for i in range(peak, len(envelope)):
        if envelope[i] < 2 * noise:
            end = i
            break
    if end is None:
        return None
    tau = (end - p_index) * dt
    if tau <= 0:
        return None
    md = -0.87 + 2.0 * math.log10(tau) + 0.0035 * epi_km
    return [round(tau, 2), round(md, 2)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['coda 0', [[1, 0, 1, 1, 19, 59, 29, 23, 13, 6, 4, 2, 1], 1.0, 4, 1, 30], [7.0, 0.93]], ['coda 1', [[0, 1, 3, 3, 1, 23, 70, 49, 39, 31, 21, 14, 7, 4, 2, 3, 3, 1], 0.5, 5, 3, 5], [4.0, 0.35]], ['coda 2', [[0, 2, 26, 78, 39, 27, 21, 14, 8, 4, 2, 0], 0.5, 2, 3, 5], [3.5, 0.24]], ['coda 3', [[0, 2, 2, 0, 1, 14, 44, 30, 21, 14, 9, 7, 5, 3, 1, 2, 0, 2], 0.5, 5, 2, 5], [4.0, 0.35]], ['coda 4', [[0, 1, 1, 19, 59, 35, 21, 12, 7, 5, 2, 1], 0.5, 3, 1, 5], [3.5, 0.24]], ['coda 5', [[2, 0, 0, 24, 72, 43, 25, 17, 13, 9, 4, 3, 1, 1, 1, 1], 2.0, 3, 2, 120], [14.0, 1.84]], ['coda 6', [[1, 1, 0, 1, 0, 20, 61, 30, 24, 19, 15, 12, 8, 6, 3, 2, 1, 0, 1, 1], 2.0, 5, 1, 120], [20.0, 2.15]], ['coda 7', [[0, 0, 1, 0, 0, 16, 50, 35, 21, 12, 8, 4, 2, 1, 1], 1.0, 5, 1, 30], [7.0, 0.93]]], [['coda 6', [[1, 1, 0, 1, 0, 20, 61, 30, 24, 19, 15, 12, 8, 6, 3, 2, 1, 0, 1, 1], 2.0, 5, 1, 120], [20.0, 2.15]], ['coda 7', [[0, 0, 1, 0, 0, 16, 50, 35, 21, 12, 8, 4, 2, 1, 1], 1.0, 5, 1, 30], [7.0, 0.93]], ['coda 8', [[0, 0, 1, 2, 9, 27, 18, 10, 7, 4, 2], 0.5, 4, 2, 5], [2.5, -0.06]], ['coda 9', [[1, 1, 17, 53, 42, 29, 23, 18, 14, 9, 6, 4, 2, 1, 1, 1, 1], 1.0, 2, 1, 30], [10.0, 1.23]], ['coda 10', [[1, 2, 0, 2, 10, 30, 18, 12, 7, 5, 2, 0, 1], 2.0, 4, 2, 120], [12.0, 1.71]], ['coda 11', [[1, 0, 10, 31, 24, 16, 8, 4, 2, 1, 0], 1.0, 2, 1, 30], [6.0, 0.79]], ['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['coda 13', [[0, 2, 1, 0, 1, 9, 29, 20, 12, 9, 6, 4, 2], 1.0, 5, 2, 30], [6.0, 0.79]]], [['coda 9', [[1, 1, 17, 53, 42, 29, 23, 18, 14, 9, 6, 4, 2, 1, 1, 1, 1], 1.0, 2, 1, 30], [10.0, 1.23]], ['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['coda 14', [[0, 1, 0, 25, 75, 45, 36, 25, 17, 13, 6, 4, 2, 1, 0, 0], 0.5, 3, 1, 5], [4.5, 0.45]], ['coda 15', [[2, 1, 2, 1, 1, 25, 75, 60, 42, 25, 15, 12, 6, 3, 0], 0.5, 5, 3, 5], [3.5, 0.24]], ['coda 16', [[0, 1, 1, 1, 0, 23, 69, 55, 27, 21, 10, 6, 3, 1, 0], 1.0, 5, 1, 30], [8.0, 1.04]], ['coda 17', [[1, 2, 22, 68, 40, 28, 19, 15, 12, 8, 6, 4, 2, 0, 2], 2.0, 2, 2, 120], [18.0, 2.06]], ['coda 18', [[1, 1, 1, 1, 10, 31, 24, 12, 9, 7, 4, 2, 1, 1, 0, 1], 0.5, 4, 1, 5], [3.5, 0.24]], ['coda 19', [[1, 1, 11, 33, 16, 12, 6, 3, 2, 1], 2.0, 2, 3, 120], [8.0, 1.36]]], [['coda 13', [[0, 2, 1, 0, 1, 9, 29, 20, 12, 9, 6, 4, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 18', [[1, 1, 1, 1, 10, 31, 24, 12, 9, 7, 4, 2, 1, 1, 0, 1], 0.5, 4, 1, 5], [3.5, 0.24]], ['coda 21', [[0, 1, 0, 8, 26, 18, 10, 6, 3, 2, 1], 0.5, 3, 1, 5], [3.0, 0.1]], ['coda 22', [[1, 1, 0, 0, 1, 23, 69, 34, 23, 13, 9, 5, 4, 3, 2, 1, 1, 0], 0.5, 5, 1, 5], [4.5, 0.45]], ['coda 23', [[0, 2, 0, 2, 1, 16, 48, 28, 19, 15, 9, 4, 3, 1, 1, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 24', [[1, 0, 1, 1, 0, 11, 35, 24, 19, 15, 9, 7, 5, 3, 2, 1, 1, 1, 0], 2.0, 5, 1, 120], [18.0, 2.06]], ['coda 25', [[1, 0, 12, 36, 18, 14, 8, 4, 3, 1, 1, 1], 1.0, 2, 2, 30], [5.0, 0.63]], ['coda 26', [[0, 0, 1, 11, 34, 17, 11, 7, 3, 1], 2.0, 3, 1, 120], [12.0, 1.71]]], [['coda 17', [[1, 2, 22, 68, 40, 28, 19, 15, 12, 8, 6, 4, 2, 0, 2], 2.0, 2, 2, 120], [18.0, 2.06]], ['coda 23', [[0, 2, 0, 2, 1, 16, 48, 28, 19, 15, 9, 4, 3, 1, 1, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 28', [[1, 2, 3, 7, 21, 16, 12, 9, 5, 3, 1, 0, 0], 0.5, 3, 3, 5], [2.5, -0.06]], ['coda 29', [[0, 0, 1, 17, 53, 42, 33, 16, 12, 9, 6, 3, 2, 1], 2.0, 3, 1, 120], [18.0, 2.06]], ['coda 30', [[2, 2, 0, 1, 2, 19, 58, 34, 27, 16, 11, 7, 5, 4, 2, 1], 2.0, 5, 2, 120], [16.0, 1.96]], ['coda 31', [[2, 3, 1, 19, 59, 47, 23, 13, 10, 6, 3, 0, 1, 3], 0.5, 3, 3, 5], [3.0, 0.1]], ['coda 32', [[1, 0, 12, 38, 26, 15, 9, 4, 3, 2, 1], 0.5, 2, 2, 5], [2.5, -0.06]], ['coda 33', [[2, 0, 11, 34, 23, 16, 8, 4, 2, 1, 0, 3], 2.0, 2, 3, 120], [10.0, 1.55]]]]
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 fixture	Actual	Expected	Outcome
coda 0	`[8.0, 1.04]`	`[7.0, 0.93]`	Failed
coda 1	`[4.0, 0.35]`	`[4.0, 0.35]`	Passed
coda 2	`[3.5, 0.24]`	`[3.5, 0.24]`	Passed
coda 3	`[4.0, 0.35]`	`[4.0, 0.35]`	Passed
coda 4	`[4.0, 0.35]`	`[3.5, 0.24]`	Failed
coda 5	`[16.0, 1.96]`	`[14.0, 1.84]`	Failed
coda 6	`[22.0, 2.23]`	`[20.0, 2.15]`	Failed
coda 7	`[8.0, 1.04]`	`[7.0, 0.93]`	Failed

SHA-256 / a7109c23c4a8175e5698cb81a018e30ad7b1c2e369ea6a1d123bbe419fcfd213

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(envelope, dt, p_index, noise, epi_km):
    if p_index >= len(envelope):
        return None
    peak = max(range(p_index, len(envelope)), key=lambda i: envelope[i])
    end = None
    for i in range(peak, len(envelope)):
        if envelope[i] <= noise:
            end = i
            break
    if end is None:
        return None
    tau = (end - p_index) * dt
    if tau <= 0:
        return None
    md = -0.87 + 2.0 * math.log10(tau) + 0.0035 * epi_km
    return [round(tau, 2), round(md, 2)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['coda 0', [[1, 0, 1, 1, 19, 59, 29, 23, 13, 6, 4, 2, 1], 1.0, 4, 1, 30], [7.0, 0.93]], ['coda 1', [[0, 1, 3, 3, 1, 23, 70, 49, 39, 31, 21, 14, 7, 4, 2, 3, 3, 1], 0.5, 5, 3, 5], [4.0, 0.35]], ['coda 2', [[0, 2, 26, 78, 39, 27, 21, 14, 8, 4, 2, 0], 0.5, 2, 3, 5], [3.5, 0.24]], ['coda 3', [[0, 2, 2, 0, 1, 14, 44, 30, 21, 14, 9, 7, 5, 3, 1, 2, 0, 2], 0.5, 5, 2, 5], [4.0, 0.35]], ['coda 4', [[0, 1, 1, 19, 59, 35, 21, 12, 7, 5, 2, 1], 0.5, 3, 1, 5], [3.5, 0.24]], ['coda 5', [[2, 0, 0, 24, 72, 43, 25, 17, 13, 9, 4, 3, 1, 1, 1, 1], 2.0, 3, 2, 120], [14.0, 1.84]], ['coda 6', [[1, 1, 0, 1, 0, 20, 61, 30, 24, 19, 15, 12, 8, 6, 3, 2, 1, 0, 1, 1], 2.0, 5, 1, 120], [20.0, 2.15]], ['coda 7', [[0, 0, 1, 0, 0, 16, 50, 35, 21, 12, 8, 4, 2, 1, 1], 1.0, 5, 1, 30], [7.0, 0.93]]], [['coda 6', [[1, 1, 0, 1, 0, 20, 61, 30, 24, 19, 15, 12, 8, 6, 3, 2, 1, 0, 1, 1], 2.0, 5, 1, 120], [20.0, 2.15]], ['coda 7', [[0, 0, 1, 0, 0, 16, 50, 35, 21, 12, 8, 4, 2, 1, 1], 1.0, 5, 1, 30], [7.0, 0.93]], ['coda 8', [[0, 0, 1, 2, 9, 27, 18, 10, 7, 4, 2], 0.5, 4, 2, 5], [2.5, -0.06]], ['coda 9', [[1, 1, 17, 53, 42, 29, 23, 18, 14, 9, 6, 4, 2, 1, 1, 1, 1], 1.0, 2, 1, 30], [10.0, 1.23]], ['coda 10', [[1, 2, 0, 2, 10, 30, 18, 12, 7, 5, 2, 0, 1], 2.0, 4, 2, 120], [12.0, 1.71]], ['coda 11', [[1, 0, 10, 31, 24, 16, 8, 4, 2, 1, 0], 1.0, 2, 1, 30], [6.0, 0.79]], ['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['coda 13', [[0, 2, 1, 0, 1, 9, 29, 20, 12, 9, 6, 4, 2], 1.0, 5, 2, 30], [6.0, 0.79]]], [['coda 9', [[1, 1, 17, 53, 42, 29, 23, 18, 14, 9, 6, 4, 2, 1, 1, 1, 1], 1.0, 2, 1, 30], [10.0, 1.23]], ['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['coda 14', [[0, 1, 0, 25, 75, 45, 36, 25, 17, 13, 6, 4, 2, 1, 0, 0], 0.5, 3, 1, 5], [4.5, 0.45]], ['coda 15', [[2, 1, 2, 1, 1, 25, 75, 60, 42, 25, 15, 12, 6, 3, 0], 0.5, 5, 3, 5], [3.5, 0.24]], ['coda 16', [[0, 1, 1, 1, 0, 23, 69, 55, 27, 21, 10, 6, 3, 1, 0], 1.0, 5, 1, 30], [8.0, 1.04]], ['coda 17', [[1, 2, 22, 68, 40, 28, 19, 15, 12, 8, 6, 4, 2, 0, 2], 2.0, 2, 2, 120], [18.0, 2.06]], ['coda 18', [[1, 1, 1, 1, 10, 31, 24, 12, 9, 7, 4, 2, 1, 1, 0, 1], 0.5, 4, 1, 5], [3.5, 0.24]], ['coda 19', [[1, 1, 11, 33, 16, 12, 6, 3, 2, 1], 2.0, 2, 3, 120], [8.0, 1.36]]], [['coda 13', [[0, 2, 1, 0, 1, 9, 29, 20, 12, 9, 6, 4, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 18', [[1, 1, 1, 1, 10, 31, 24, 12, 9, 7, 4, 2, 1, 1, 0, 1], 0.5, 4, 1, 5], [3.5, 0.24]], ['coda 21', [[0, 1, 0, 8, 26, 18, 10, 6, 3, 2, 1], 0.5, 3, 1, 5], [3.0, 0.1]], ['coda 22', [[1, 1, 0, 0, 1, 23, 69, 34, 23, 13, 9, 5, 4, 3, 2, 1, 1, 0], 0.5, 5, 1, 5], [4.5, 0.45]], ['coda 23', [[0, 2, 0, 2, 1, 16, 48, 28, 19, 15, 9, 4, 3, 1, 1, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 24', [[1, 0, 1, 1, 0, 11, 35, 24, 19, 15, 9, 7, 5, 3, 2, 1, 1, 1, 0], 2.0, 5, 1, 120], [18.0, 2.06]], ['coda 25', [[1, 0, 12, 36, 18, 14, 8, 4, 3, 1, 1, 1], 1.0, 2, 2, 30], [5.0, 0.63]], ['coda 26', [[0, 0, 1, 11, 34, 17, 11, 7, 3, 1], 2.0, 3, 1, 120], [12.0, 1.71]]], [['coda 17', [[1, 2, 22, 68, 40, 28, 19, 15, 12, 8, 6, 4, 2, 0, 2], 2.0, 2, 2, 120], [18.0, 2.06]], ['coda 23', [[0, 2, 0, 2, 1, 16, 48, 28, 19, 15, 9, 4, 3, 1, 1, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 28', [[1, 2, 3, 7, 21, 16, 12, 9, 5, 3, 1, 0, 0], 0.5, 3, 3, 5], [2.5, -0.06]], ['coda 29', [[0, 0, 1, 17, 53, 42, 33, 16, 12, 9, 6, 3, 2, 1], 2.0, 3, 1, 120], [18.0, 2.06]], ['coda 30', [[2, 2, 0, 1, 2, 19, 58, 34, 27, 16, 11, 7, 5, 4, 2, 1], 2.0, 5, 2, 120], [16.0, 1.96]], ['coda 31', [[2, 3, 1, 19, 59, 47, 23, 13, 10, 6, 3, 0, 1, 3], 0.5, 3, 3, 5], [3.0, 0.1]], ['coda 32', [[1, 0, 12, 38, 26, 15, 9, 4, 3, 2, 1], 0.5, 2, 2, 5], [2.5, -0.06]], ['coda 33', [[2, 0, 11, 34, 23, 16, 8, 4, 2, 1, 0, 3], 2.0, 2, 3, 120], [10.0, 1.55]]]]
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 fixture	Actual	Expected	Outcome
coda 0	`[8.0, 1.04]`	`[7.0, 0.93]`	Failed
coda 1	`[4.5, 0.45]`	`[4.0, 0.35]`	Failed
coda 2	`[4.0, 0.35]`	`[3.5, 0.24]`	Failed
coda 3	`[4.5, 0.45]`	`[4.0, 0.35]`	Failed
coda 4	`[4.0, 0.35]`	`[3.5, 0.24]`	Failed
coda 5	`[18.0, 2.06]`	`[14.0, 1.84]`	Failed
coda 6	`[22.0, 2.23]`	`[20.0, 2.15]`	Failed
coda 7	`[8.0, 1.04]`	`[7.0, 0.93]`	Failed

SHA-256 / 4b5ff02bd85189007918c61ea9fccb2d02b5f926ddb4c4dc3bcf9ebd3f789219

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(envelope, dt, p_index, noise, epi_km):
    if p_index >= len(envelope):
        return None
    peak = max(range(p_index, len(envelope)), key=lambda i: envelope[i])
    end = None
    for i in range(peak, len(envelope)):
        if envelope[i] <= 2 * noise:
            end = i
            break
    if end is None:
        return None
    tau = (end - p_index) * dt
    if tau <= 0:
        return None
    md = -0.87 + 2.0 * math.log10(tau) + 0.0035 * epi_km
    return [round(tau, 2), round(md, 2)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['coda 0', [[1, 0, 1, 1, 19, 59, 29, 23, 13, 6, 4, 2, 1], 1.0, 4, 1, 30], [7.0, 0.93]], ['coda 1', [[0, 1, 3, 3, 1, 23, 70, 49, 39, 31, 21, 14, 7, 4, 2, 3, 3, 1], 0.5, 5, 3, 5], [4.0, 0.35]], ['coda 2', [[0, 2, 26, 78, 39, 27, 21, 14, 8, 4, 2, 0], 0.5, 2, 3, 5], [3.5, 0.24]], ['coda 3', [[0, 2, 2, 0, 1, 14, 44, 30, 21, 14, 9, 7, 5, 3, 1, 2, 0, 2], 0.5, 5, 2, 5], [4.0, 0.35]], ['coda 4', [[0, 1, 1, 19, 59, 35, 21, 12, 7, 5, 2, 1], 0.5, 3, 1, 5], [3.5, 0.24]], ['coda 5', [[2, 0, 0, 24, 72, 43, 25, 17, 13, 9, 4, 3, 1, 1, 1, 1], 2.0, 3, 2, 120], [14.0, 1.84]], ['coda 6', [[1, 1, 0, 1, 0, 20, 61, 30, 24, 19, 15, 12, 8, 6, 3, 2, 1, 0, 1, 1], 2.0, 5, 1, 120], [20.0, 2.15]], ['coda 7', [[0, 0, 1, 0, 0, 16, 50, 35, 21, 12, 8, 4, 2, 1, 1], 1.0, 5, 1, 30], [7.0, 0.93]]], [['coda 6', [[1, 1, 0, 1, 0, 20, 61, 30, 24, 19, 15, 12, 8, 6, 3, 2, 1, 0, 1, 1], 2.0, 5, 1, 120], [20.0, 2.15]], ['coda 7', [[0, 0, 1, 0, 0, 16, 50, 35, 21, 12, 8, 4, 2, 1, 1], 1.0, 5, 1, 30], [7.0, 0.93]], ['coda 8', [[0, 0, 1, 2, 9, 27, 18, 10, 7, 4, 2], 0.5, 4, 2, 5], [2.5, -0.06]], ['coda 9', [[1, 1, 17, 53, 42, 29, 23, 18, 14, 9, 6, 4, 2, 1, 1, 1, 1], 1.0, 2, 1, 30], [10.0, 1.23]], ['coda 10', [[1, 2, 0, 2, 10, 30, 18, 12, 7, 5, 2, 0, 1], 2.0, 4, 2, 120], [12.0, 1.71]], ['coda 11', [[1, 0, 10, 31, 24, 16, 8, 4, 2, 1, 0], 1.0, 2, 1, 30], [6.0, 0.79]], ['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['coda 13', [[0, 2, 1, 0, 1, 9, 29, 20, 12, 9, 6, 4, 2], 1.0, 5, 2, 30], [6.0, 0.79]]], [['coda 9', [[1, 1, 17, 53, 42, 29, 23, 18, 14, 9, 6, 4, 2, 1, 1, 1, 1], 1.0, 2, 1, 30], [10.0, 1.23]], ['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['coda 14', [[0, 1, 0, 25, 75, 45, 36, 25, 17, 13, 6, 4, 2, 1, 0, 0], 0.5, 3, 1, 5], [4.5, 0.45]], ['coda 15', [[2, 1, 2, 1, 1, 25, 75, 60, 42, 25, 15, 12, 6, 3, 0], 0.5, 5, 3, 5], [3.5, 0.24]], ['coda 16', [[0, 1, 1, 1, 0, 23, 69, 55, 27, 21, 10, 6, 3, 1, 0], 1.0, 5, 1, 30], [8.0, 1.04]], ['coda 17', [[1, 2, 22, 68, 40, 28, 19, 15, 12, 8, 6, 4, 2, 0, 2], 2.0, 2, 2, 120], [18.0, 2.06]], ['coda 18', [[1, 1, 1, 1, 10, 31, 24, 12, 9, 7, 4, 2, 1, 1, 0, 1], 0.5, 4, 1, 5], [3.5, 0.24]], ['coda 19', [[1, 1, 11, 33, 16, 12, 6, 3, 2, 1], 2.0, 2, 3, 120], [8.0, 1.36]]], [['coda 13', [[0, 2, 1, 0, 1, 9, 29, 20, 12, 9, 6, 4, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 18', [[1, 1, 1, 1, 10, 31, 24, 12, 9, 7, 4, 2, 1, 1, 0, 1], 0.5, 4, 1, 5], [3.5, 0.24]], ['coda 21', [[0, 1, 0, 8, 26, 18, 10, 6, 3, 2, 1], 0.5, 3, 1, 5], [3.0, 0.1]], ['coda 22', [[1, 1, 0, 0, 1, 23, 69, 34, 23, 13, 9, 5, 4, 3, 2, 1, 1, 0], 0.5, 5, 1, 5], [4.5, 0.45]], ['coda 23', [[0, 2, 0, 2, 1, 16, 48, 28, 19, 15, 9, 4, 3, 1, 1, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 24', [[1, 0, 1, 1, 0, 11, 35, 24, 19, 15, 9, 7, 5, 3, 2, 1, 1, 1, 0], 2.0, 5, 1, 120], [18.0, 2.06]], ['coda 25', [[1, 0, 12, 36, 18, 14, 8, 4, 3, 1, 1, 1], 1.0, 2, 2, 30], [5.0, 0.63]], ['coda 26', [[0, 0, 1, 11, 34, 17, 11, 7, 3, 1], 2.0, 3, 1, 120], [12.0, 1.71]]], [['coda 17', [[1, 2, 22, 68, 40, 28, 19, 15, 12, 8, 6, 4, 2, 0, 2], 2.0, 2, 2, 120], [18.0, 2.06]], ['coda 23', [[0, 2, 0, 2, 1, 16, 48, 28, 19, 15, 9, 4, 3, 1, 1, 2], 1.0, 5, 2, 30], [6.0, 0.79]], ['coda 28', [[1, 2, 3, 7, 21, 16, 12, 9, 5, 3, 1, 0, 0], 0.5, 3, 3, 5], [2.5, -0.06]], ['coda 29', [[0, 0, 1, 17, 53, 42, 33, 16, 12, 9, 6, 3, 2, 1], 2.0, 3, 1, 120], [18.0, 2.06]], ['coda 30', [[2, 2, 0, 1, 2, 19, 58, 34, 27, 16, 11, 7, 5, 4, 2, 1], 2.0, 5, 2, 120], [16.0, 1.96]], ['coda 31', [[2, 3, 1, 19, 59, 47, 23, 13, 10, 6, 3, 0, 1, 3], 0.5, 3, 3, 5], [3.0, 0.1]], ['coda 32', [[1, 0, 12, 38, 26, 15, 9, 4, 3, 2, 1], 0.5, 2, 2, 5], [2.5, -0.06]], ['coda 33', [[2, 0, 11, 34, 23, 16, 8, 4, 2, 1, 0, 3], 2.0, 2, 3, 120], [10.0, 1.55]]]]
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 fixture	Actual	Expected	Outcome
coda 0	`[7.0, 0.93]`	`[7.0, 0.93]`	Passed
coda 1	`[4.0, 0.35]`	`[4.0, 0.35]`	Passed
coda 2	`[3.5, 0.24]`	`[3.5, 0.24]`	Passed
coda 3	`[4.0, 0.35]`	`[4.0, 0.35]`	Passed
coda 4	`[3.5, 0.24]`	`[3.5, 0.24]`	Passed
coda 5	`[14.0, 1.84]`	`[14.0, 1.84]`	Passed
coda 6	`[20.0, 2.15]`	`[20.0, 2.15]`	Passed
coda 7	`[7.0, 0.93]`	`[7.0, 0.93]`	Passed

SHA-256 / 6416a0470160f5f71a82447734d2babad8a1f30cb65fda52fe938aa135fa5782

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 2026-09-29T14:48:29.922575+00:00.

Case digest / ec1076737baf4e58c6ef4358108ab39caf62e2b6a363f9f7fab6ea468b5f472a