{"abstract":"Traces with a DC offset integrate into huge drifting displacements.","category":"Seismic magnitude estimation","checks":8,"contract":"Velocity-sensor counts, sensitivity counts per m/s, sample interval s. Remove the mean, convert to m/s, integrate with the trapezoid rule from 0, take the maximum absolute displacement, multiply by the Wood-Anderson gain 2080 and convert to mm. Return mm rounded to 1e-4, None for an empty trace.","contract_signature":"counts, sens, dt","evaluation_group":"w2-seismic_magnitude_estimation-wood-anderson-sim","failed_approach":"Removing only the first sample leaves the mean offset of the rest.","family":"w2-seismic_magnitude_estimation-wood-anderson-sim-mean-removal","id":"FA-71551","implementations":{"attempt":{"sha256":"0884083079b3a70649a33f4a2fe8c49df5774f0276e0271db2727555d275f8cd","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(counts, sens, dt):\n    if not counts:\n        return None\n    mean = counts[0]\n    vel = [(c - mean) / sens for c in counts]\n    disp = [0.0]\n    for i in range(1, len(vel)):\n        disp.append(disp[-1] + 0.5 * (vel[i - 1] + vel[i]) * dt)\n    peak = max(abs(x) for x in disp)\n    return round(peak * 2080 * 1000, 4)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['trace 0', [[-399, 158, 716, 1343, 399, -234, 349, 919], 500000000.0, 0.02], 0.0492], ['trace 1', [[-438, -422, -845, 107, -288, 724, -435, -632, 690], 100000000.0, 0.01], 0.1913], ['trace 2', [[8, 47, 118, -519, -421, -54, -238, -121], 100000000.0, 0.01], 0.0842], ['trace 3', [[-701, 88, -234, -70, -529, -1002, 304, -1260, -994, 400], 100000000.0, 0.01], 0.1598], ['trace 4', [[-686, 544, 277, -1046, -766, -1235, 329, -1152, -874, 219], 100000000.0, 0.01], 0.2646], ['trace 5', [[1259, -39, 1475, 880, 416, 768, 982, -232], 1500000000.0, 0.02], 0.0136], ['trace 6', [[967, -475, -512, 255, 516, 486, -840, 288], 1500000000.0, 0.01], 0.0088], ['trace 7', [[22, -1189, -875, -394, 216], 500000000.0, 0.02], 0.0764]], [['trace 3', [[-701, 88, -234, -70, -529, -1002, 304, -1260, -994, 400], 100000000.0, 0.01], 0.1598], ['trace 6', [[967, -475, -512, 255, 516, 486, -840, 288], 1500000000.0, 0.01], 0.0088], ['trace 7', [[22, -1189, -875, -394, 216], 500000000.0, 0.02], 0.0764], ['trace 8', [[491, -743, 168, -106], 100000000.0, 0.01], 0.0662], ['trace 9', [[1140, 675, -129, 1466, 1180, 1409, 1273, 156], 500000000.0, 0.02], 0.0699], ['trace 10', [[295, -693, -527, -749, -313, 39, 217, -925, 433], 1500000000.0, 0.01], 0.0137], ['trace 11', [[415, 520, -255, 348, 660, -938], 500000000.0, 0.02], 0.0541], ['trace 12', [[-597, -489, -301, -271, -999, -558, -230, -970, -1048], 500000000.0, 0.02], 0.0514]], [['trace 6', [[967, -475, -512, 255, 516, 486, -840, 288], 1500000000.0, 0.01], 0.0088], ['trace 11', [[415, 520, -255, 348, 660, -938], 500000000.0, 0.02], 0.0541], ['trace 14', [[338, -532, -974, 859, 966, 558], 100000000.0, 0.01], 0.3151], ['trace 15', [[143, 170, -64, 138, 634], 100000000.0, 0.01], 0.0761], ['trace 16', [[1183, 1265, 1030, 749, -390], 500000000.0, 0.02], 0.0798], ['trace 17', [[423, -354, -610, -304, 513, -195, -84, 296], 1500000000.0, 0.02], 0.0218], ['trace 18', [[914, 28, -594, 554, -691, 34, 863, 716, -229, 744], 100000000.0, 0.01], 0.2909], ['trace 19', [[1319, 651, 570, 304, 1072], 1500000000.0, 0.01], 0.0057]], [['trace 9', [[1140, 675, -129, 1466, 1180, 1409, 1273, 156], 500000000.0, 0.02], 0.0699], ['trace 16', [[1183, 1265, 1030, 749, -390], 500000000.0, 0.02], 0.0798], ['trace 21', [[561, 856, 710, 319, 742, 1285, -221, 763], 100000000.0, 0.01], 0.0864], ['trace 22', [[-228, 382, -252, 552, 320, -776], 100000000.0, 0.01], 0.1517], ['trace 23', [[-486, 859, 193, 1092, 1350, -353], 500000000.0, 0.02], 0.0717], ['trace 24', [[-179, 4, 317, 984], 1500000000.0, 0.02], 0.0136], ['trace 25', [[-431, 933, -842, 85, -489, -992, -686, -918], 500000000.0, 0.02], 0.1153], ['trace 26', [[-347, -149, -735, -306, -1255], 1500000000.0, 0.01], 0.0064]], [['trace 0', [[-399, 158, 716, 1343, 399, -234, 349, 919], 500000000.0, 0.02], 0.0492], ['trace 12', [[-597, -489, -301, -271, -999, -558, -230, -970, -1048], 500000000.0, 0.02], 0.0514], ['trace 21', [[561, 856, 710, 319, 742, 1285, -221, 763], 100000000.0, 0.01], 0.0864], ['trace 28', [[-1202, -1275, 528, -292, -12, -129, -528, 349], 100000000.0, 0.01], 0.2021], ['trace 29', [[-178, 10, 1361, 707, 1375, 364, 582, 1449, 423], 1500000000.0, 0.01], 0.0106], ['asymmetric pulse', [[0, 800, 1200, 400, -200, -100], 1000000000.0, 0.01], 0.0239], ['empty', [[], 1000000000.0, 0.01], None], ['offset step', [[1000, 1000, 3000, 1000, 1000], 1000000000.0, 0.01], 0.0166]]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"f51ef74e15ebfd9e12541db71ef757a9db9c2d58886cb523dc339e10cec20b46","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(counts, sens, dt):\n    if not counts:\n        return None\n    mean = 0.0\n    vel = [(c - mean) / sens for c in counts]\n    disp = [0.0]\n    for i in range(1, len(vel)):\n        disp.append(disp[-1] + 0.5 * (vel[i - 1] + vel[i]) * dt)\n    peak = max(abs(x) for x in disp)\n    return round(peak * 2080 * 1000, 4)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['trace 0', [[-399, 158, 716, 1343, 399, -234, 349, 919], 500000000.0, 0.02], 0.0492], ['trace 1', [[-438, -422, -845, 107, -288, 724, -435, -632, 690], 100000000.0, 0.01], 0.1913], ['trace 2', [[8, 47, 118, -519, -421, -54, -238, -121], 100000000.0, 0.01], 0.0842], ['trace 3', [[-701, 88, -234, -70, -529, -1002, 304, -1260, -994, 400], 100000000.0, 0.01], 0.1598], ['trace 4', [[-686, 544, 277, -1046, -766, -1235, 329, -1152, -874, 219], 100000000.0, 0.01], 0.2646], ['trace 5', [[1259, -39, 1475, 880, 416, 768, 982, -232], 1500000000.0, 0.02], 0.0136], ['trace 6', [[967, -475, -512, 255, 516, 486, -840, 288], 1500000000.0, 0.01], 0.0088], ['trace 7', [[22, -1189, -875, -394, 216], 500000000.0, 0.02], 0.0764]], [['trace 3', [[-701, 88, -234, -70, -529, -1002, 304, -1260, -994, 400], 100000000.0, 0.01], 0.1598], ['trace 6', [[967, -475, -512, 255, 516, 486, -840, 288], 1500000000.0, 0.01], 0.0088], ['trace 7', [[22, -1189, -875, -394, 216], 500000000.0, 0.02], 0.0764], ['trace 8', [[491, -743, 168, -106], 100000000.0, 0.01], 0.0662], ['trace 9', [[1140, 675, -129, 1466, 1180, 1409, 1273, 156], 500000000.0, 0.02], 0.0699], ['trace 10', [[295, -693, -527, -749, -313, 39, 217, -925, 433], 1500000000.0, 0.01], 0.0137], ['trace 11', [[415, 520, -255, 348, 660, -938], 500000000.0, 0.02], 0.0541], ['trace 12', [[-597, -489, -301, -271, -999, -558, -230, -970, -1048], 500000000.0, 0.02], 0.0514]], [['trace 6', [[967, -475, -512, 255, 516, 486, -840, 288], 1500000000.0, 0.01], 0.0088], ['trace 11', [[415, 520, -255, 348, 660, -938], 500000000.0, 0.02], 0.0541], ['trace 14', [[338, -532, -974, 859, 966, 558], 100000000.0, 0.01], 0.3151], ['trace 15', [[143, 170, -64, 138, 634], 100000000.0, 0.01], 0.0761], ['trace 16', [[1183, 1265, 1030, 749, -390], 500000000.0, 0.02], 0.0798], ['trace 17', [[423, -354, -610, -304, 513, -195, -84, 296], 1500000000.0, 0.02], 0.0218], ['trace 18', [[914, 28, -594, 554, -691, 34, 863, 716, -229, 744], 100000000.0, 0.01], 0.2909], ['trace 19', [[1319, 651, 570, 304, 1072], 1500000000.0, 0.01], 0.0057]], [['trace 9', [[1140, 675, -129, 1466, 1180, 1409, 1273, 156], 500000000.0, 0.02], 0.0699], ['trace 16', [[1183, 1265, 1030, 749, -390], 500000000.0, 0.02], 0.0798], ['trace 21', [[561, 856, 710, 319, 742, 1285, -221, 763], 100000000.0, 0.01], 0.0864], ['trace 22', [[-228, 382, -252, 552, 320, -776], 100000000.0, 0.01], 0.1517], ['trace 23', [[-486, 859, 193, 1092, 1350, -353], 500000000.0, 0.02], 0.0717], ['trace 24', [[-179, 4, 317, 984], 1500000000.0, 0.02], 0.0136], ['trace 25', [[-431, 933, -842, 85, -489, -992, -686, -918], 500000000.0, 0.02], 0.1153], ['trace 26', [[-347, -149, -735, -306, -1255], 1500000000.0, 0.01], 0.0064]], [['trace 0', [[-399, 158, 716, 1343, 399, -234, 349, 919], 500000000.0, 0.02], 0.0492], ['trace 12', [[-597, -489, -301, -271, -999, -558, -230, -970, -1048], 500000000.0, 0.02], 0.0514], ['trace 21', [[561, 856, 710, 319, 742, 1285, -221, 763], 100000000.0, 0.01], 0.0864], ['trace 28', [[-1202, -1275, 528, -292, -12, -129, -528, 349], 100000000.0, 0.01], 0.2021], ['trace 29', [[-178, 10, 1361, 707, 1375, 364, 582, 1449, 423], 1500000000.0, 0.01], 0.0106], ['asymmetric pulse', [[0, 800, 1200, 400, -200, -100], 1000000000.0, 0.01], 0.0239], ['empty', [[], 1000000000.0, 0.01], None], ['offset step', [[1000, 1000, 3000, 1000, 1000], 1000000000.0, 0.01], 0.0166]]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-seismic_magnitude_estimation-wood-anderson-sim-mean-removal","generated_at":"2026-09-29T14:48:30.704185+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Wood-Anderson amplitudes are the input to local magnitude.","root_cause":"The DC offset is not removed before integration.","sha256":"6c374ffa32e2a69785758439a566bd3b8ec98baaef5dd41e962268a7b85a36c1","title":"Wood-Anderson amplitude simulation: mean removal · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":40.24,"exit_code":1,"observations":[{"actual":0.4812,"check":"trace 0","expected":0.0492,"passed":false},{"actual":0.3825,"check":"trace 1","expected":0.1913,"passed":false},{"actual":0.2453,"check":"trace 2","expected":0.0842,"passed":false},{"actual":0.5166,"check":"trace 3","expected":0.1598,"passed":false},{"actual":0.4196,"check":"trace 4","expected":0.2646,"passed":false},{"actual":0.1059,"check":"trace 5","expected":0.0136,"passed":false},{"actual":0.0931,"check":"trace 6","expected":0.0088,"passed":false},{"actual":0.2019,"check":"trace 7","expected":0.0764,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"trace 0\", \"actual\": 0.4812, \"expected\": 0.0492, \"passed\": false}, {\"check\": \"trace 1\", \"actual\": 0.3825, \"expected\": 0.1913, \"passed\": false}, {\"check\": \"trace 2\", \"actual\": 0.2453, \"expected\": 0.0842, \"passed\": false}, {\"check\": \"trace 3\", \"actual\": 0.5166, \"expected\": 0.1598, \"passed\": false}, {\"check\": \"trace 4\", \"actual\": 0.4196, \"expected\": 0.2646, \"passed\": false}, {\"check\": \"trace 5\", \"actual\": 0.1059, \"expected\": 0.0136, \"passed\": false}, {\"check\": \"trace 6\", \"actual\": 0.0931, \"expected\": 0.0088, \"passed\": false}, {\"check\": \"trace 7\", \"actual\": 0.2019, \"expected\": 0.0764, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.19,"exit_code":1,"observations":[{"actual":0.2489,"check":"trace 0","expected":0.0492,"passed":false},{"actual":0.3524,"check":"trace 1","expected":0.1913,"passed":false},{"actual":0.2337,"check":"trace 2","expected":0.0842,"passed":false},{"actual":0.8003,"check":"trace 3","expected":0.1598,"passed":false},{"actual":0.8646,"check":"trace 4","expected":0.2646,"passed":false},{"actual":0.1385,"check":"trace 5","expected":0.0136,"passed":false},{"actual":0.0071,"check":"trace 6","expected":0.0088,"passed":false},{"actual":0.1946,"check":"trace 7","expected":0.0764,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"trace 0\", \"actual\": 0.2489, \"expected\": 0.0492, \"passed\": false}, {\"check\": \"trace 1\", \"actual\": 0.3524, \"expected\": 0.1913, \"passed\": false}, {\"check\": \"trace 2\", \"actual\": 0.2337, \"expected\": 0.0842, \"passed\": false}, {\"check\": \"trace 3\", \"actual\": 0.8003, \"expected\": 0.1598, \"passed\": false}, {\"check\": \"trace 4\", \"actual\": 0.8646, \"expected\": 0.2646, \"passed\": false}, {\"check\": \"trace 5\", \"actual\": 0.1385, \"expected\": 0.0136, \"passed\": false}, {\"check\": \"trace 6\", \"actual\": 0.0071, \"expected\": 0.0088, \"passed\": false}, {\"check\": \"trace 7\", \"actual\": 0.1946, \"expected\": 0.0764, \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}