FA-71486 / Seismic magnitude estimation / Open access

Coda duration magnitude: duration log base · case 01

Md grows too fast with duration.

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

ROOT CAUSE

The duration term uses the natural log.

VERIFIED REPAIR

Use log10 of duration in seconds.

Unsuccessful approach: Dividing by dt uses sample counts instead of seconds.

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.log(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 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 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 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 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 20', [[2, 0, 0, 1, 2, 10, 31, 18, 10, 8, 4, 3, 1, 2], 2.0, 5, 3, 120], [10.0, 1.55]]], [['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 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 27', [[1, 1, 0, 8, 24, 16, 9, 5, 3, 1], 2.0, 3, 1, 120], [12.0, 1.71]]], [['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['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]], ['coda never ends', [[0, 0, 40, 30, 25, 20], 1.0, 2, 1, 10], None]]]
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, 3.13]`	`[7.0, 0.93]`	Failed
coda 1	`[4.0, 1.92]`	`[4.0, 0.35]`	Failed
coda 2	`[3.5, 1.65]`	`[3.5, 0.24]`	Failed
coda 3	`[4.0, 1.92]`	`[4.0, 0.35]`	Failed
coda 4	`[3.5, 1.65]`	`[3.5, 0.24]`	Failed
coda 5	`[14.0, 4.83]`	`[14.0, 1.84]`	Failed
coda 6	`[20.0, 5.54]`	`[20.0, 2.15]`	Failed
coda 7	`[7.0, 3.13]`	`[7.0, 0.93]`	Failed

SHA-256 / 4fd63cc06597e43eec3b922a1b4431650c73d06a3fadfc39afe7225f08a0bba5

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] <= 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 / dt) + 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 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 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 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 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 20', [[2, 0, 0, 1, 2, 10, 31, 18, 10, 8, 4, 3, 1, 2], 2.0, 5, 3, 120], [10.0, 1.55]]], [['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 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 27', [[1, 1, 0, 8, 24, 16, 9, 5, 3, 1], 2.0, 3, 1, 120], [12.0, 1.71]]], [['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['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]], ['coda never ends', [[0, 0, 40, 30, 25, 20], 1.0, 2, 1, 10], None]]]
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, 0.95]`	`[4.0, 0.35]`	Failed
coda 2	`[3.5, 0.84]`	`[3.5, 0.24]`	Failed
coda 3	`[4.0, 0.95]`	`[4.0, 0.35]`	Failed
coda 4	`[3.5, 0.84]`	`[3.5, 0.24]`	Failed
coda 5	`[14.0, 1.24]`	`[14.0, 1.84]`	Failed
coda 6	`[20.0, 1.55]`	`[20.0, 2.15]`	Failed
coda 7	`[7.0, 0.93]`	`[7.0, 0.93]`	Passed

SHA-256 / 5c5095434d79062056b999db408421d3b32cc0c09af01b538f19a9f07baf83b3

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 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 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 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 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 20', [[2, 0, 0, 1, 2, 10, 31, 18, 10, 8, 4, 3, 1, 2], 2.0, 5, 3, 120], [10.0, 1.55]]], [['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 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 27', [[1, 1, 0, 8, 24, 16, 9, 5, 3, 1], 2.0, 3, 1, 120], [12.0, 1.71]]], [['coda 12', [[2, 1, 9, 28, 22, 13, 9, 7, 5, 4, 2, 2], 1.0, 2, 2, 30], [7.0, 0.93]], ['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]], ['coda never ends', [[0, 0, 40, 30, 25, 20], 1.0, 2, 1, 10], None]]]
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 / 44e6a9fbc64ce6d1d383f8308daf7632afec1c574535649cf5794b5a0d9d418d

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 2026-09-29T14:48:30.050368+00:00.

Case digest / fbb8e629434415ba2994ea354ca7d2aa2d100f90694279c1da53942abe2f34c0