{"abstract":"Wind exactly at the stow limit does not stow the plant.","category":"Solar tracker geometry","checks":7,"contract":"readings are [value or None, age_s] per anemometer. A reading is valid when value is not None and age <= max_age. Fewer than n_required valid readings: ['stow', 'sensor', None]. Otherwise use the highest valid value: >= stow_at gives ['stow', 'wind', v], else ['track', 'ok', v].","contract_signature":"readings, max_age, stow_at, n_required","evaluation_group":"w2-solar_tracker_geometry-anemometer-failsafe","failed_approach":"Rounding the peak stows early for readings just below the limit.","family":"w2-solar_tracker_geometry-anemometer-failsafe-stow-threshold","id":"FA-93736","implementations":{"attempt":{"sha256":"328f717ed3e8d69700352209d51fbf8101708aedbdd02a23390475d4d9a3fada","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(readings, max_age, stow_at, n_required):\n    valid = [v for v, age in readings if v is not None and age <= max_age]\n    if len(valid) < n_required:\n        return ['stow', 'sensor', None]\n    peak = max(valid)\n    if round(peak) >= stow_at:\n        return ['stow', 'wind', peak]\n    return ['track', 'ok', peak]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[15, 30], [12, 120], [None, 0], [3.5, 0]], 30, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[14.5, 5], [8, 5], [22, 60]], 60, 15, 2], ['stow', 'wind', 22]],\n  ['control 2', [[[8, 60], [8, 120]], 60, 18, 1], ['track', 'ok', 8]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[12, 120], [3.5, 5], [15, 60], [12, 120]], 60, 15, 2],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[8, 60], [0, 10], [14.5, 10]], 60, 18, 1], ['track', 'ok', 14.5]],\n  ['control 2', [[[3.5, 61], [22, 61], [22, 10], [16.5, 30]], 60, 18, 1], ['stow', 'wind', 22]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[0, 30], [15, 0], [None, 61], [22, 61]], 60, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[22, 61], [22, 120]], 30, 18, 2], ['stow', 'sensor', None]],\n  ['control 2', [[[3.5, 30], [15, 0], [None, 61], [None, 30]], 60, 18, 2], ['track', 'ok', 15]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[15, 10], [12, 61], [14.5, 60], [None, 60]], 30, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[3.5, 5], [22, 30]], 30, 18, 2], ['stow', 'wind', 22]],\n  ['control 2', [[[22, 0], [3.5, 60], [12, 30], [14.5, 5]], 30, 15, 1], ['stow', 'wind', 22]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[None, 0], [15, 61], [15, 10], [15, 5]], 60, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[3.5, 61], [0, 5], [0, 60], [14.5, 120]], 60, 18, 1], ['track', 'ok', 0]],\n  ['control 2', [[[15, 10], [12, 61], [14.5, 60], [None, 60]], 30, 15, 1], ['stow', 'wind', 15]]]]\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":"1cc65e21bb250ff5ab5985147f2a1e7066d47ac67f659c059e10c6edaca91d79","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(readings, max_age, stow_at, n_required):\n    valid = [v for v, age in readings if v is not None and age <= max_age]\n    if len(valid) < n_required:\n        return ['stow', 'sensor', None]\n    peak = max(valid)\n    if peak > stow_at:\n        return ['stow', 'wind', peak]\n    return ['track', 'ok', peak]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[15, 30], [12, 120], [None, 0], [3.5, 0]], 30, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[14.5, 5], [8, 5], [22, 60]], 60, 15, 2], ['stow', 'wind', 22]],\n  ['control 2', [[[8, 60], [8, 120]], 60, 18, 1], ['track', 'ok', 8]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[12, 120], [3.5, 5], [15, 60], [12, 120]], 60, 15, 2],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[8, 60], [0, 10], [14.5, 10]], 60, 18, 1], ['track', 'ok', 14.5]],\n  ['control 2', [[[3.5, 61], [22, 61], [22, 10], [16.5, 30]], 60, 18, 1], ['stow', 'wind', 22]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[0, 30], [15, 0], [None, 61], [22, 61]], 60, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[22, 61], [22, 120]], 30, 18, 2], ['stow', 'sensor', None]],\n  ['control 2', [[[3.5, 30], [15, 0], [None, 61], [None, 30]], 60, 18, 2], ['track', 'ok', 15]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[15, 10], [12, 61], [14.5, 60], [None, 60]], 30, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[3.5, 5], [22, 30]], 30, 18, 2], ['stow', 'wind', 22]],\n  ['control 2', [[[22, 0], [3.5, 60], [12, 30], [14.5, 5]], 30, 15, 1], ['stow', 'wind', 22]]],\n [['boundary: reading exactly max_age old', [[[10, 60]], 60, 15, 1], ['track', 'ok', 10]],\n  ['boundary: calm zero reading', [[[0, 5], [None, 5]], 60, 15, 1], ['track', 'ok', 0]],\n  ['boundary: wind at stow limit', [[[15, 5], [4, 5]], 60, 15, 2], ['stow', 'wind', 15]],\n  ['regression: reading just below limit', [[[17.6, 5]], 60, 18, 1], ['track', 'ok', 17.6]],\n  ['regression: stow threshold', [[[None, 0], [15, 61], [15, 10], [15, 5]], 60, 15, 1],\n   ['stow', 'wind', 15]],\n  ['control 1', [[[3.5, 61], [0, 5], [0, 60], [14.5, 120]], 60, 18, 1], ['track', 'ok', 0]],\n  ['control 2', [[[15, 10], [12, 61], [14.5, 60], [None, 60]], 30, 15, 1], ['stow', 'wind', 15]]]]\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":"Deterministic stipulated toy contract for teaching; no claim of conformance with any standard, vendor protocol or production controller. 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-solar_tracker_geometry-anemometer-failsafe-stow-threshold","generated_at":"2026-09-29T14:51:57.851357+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Single-axis and dual-axis solar trackers turn a sun direction into actuator commands; a sign, frame or limit mistake points a whole plant away from the sun or into a mechanical stop.","root_cause":"The stow comparison is strict.","sha256":"161c644d8f8171ea409ff94b5001895558dd22e9960727f97f6b9ac9e8544a17","title":"Anemometer fail-safe stow voting: stow threshold · 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":40.586,"exit_code":1,"observations":[{"actual":["track","ok",10],"check":"boundary: reading exactly max_age old","expected":["track","ok",10],"passed":true},{"actual":["track","ok",0],"check":"boundary: calm zero reading","expected":["track","ok",0],"passed":true},{"actual":["stow","wind",15],"check":"boundary: wind at stow limit","expected":["stow","wind",15],"passed":true},{"actual":["stow","wind",17.6],"check":"regression: reading just below limit","expected":["track","ok",17.6],"passed":false},{"actual":["stow","wind",15],"check":"regression: stow threshold","expected":["stow","wind",15],"passed":true},{"actual":["stow","wind",22],"check":"control 1","expected":["stow","wind",22],"passed":true},{"actual":["track","ok",8],"check":"control 2","expected":["track","ok",8],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary: reading exactly max_age old\", \"actual\": [\"track\", \"ok\", 10], \"expected\": [\"track\", \"ok\", 10], \"passed\": true}, {\"check\": \"boundary: calm zero reading\", \"actual\": [\"track\", \"ok\", 0], \"expected\": [\"track\", \"ok\", 0], \"passed\": true}, {\"check\": \"boundary: wind at stow limit\", \"actual\": [\"stow\", \"wind\", 15], \"expected\": [\"stow\", \"wind\", 15], \"passed\": true}, {\"check\": \"regression: reading just below limit\", \"actual\": [\"stow\", \"wind\", 17.6], \"expected\": [\"track\", \"ok\", 17.6], \"passed\": false}, {\"check\": \"regression: stow threshold\", \"actual\": [\"stow\", \"wind\", 15], \"expected\": [\"stow\", \"wind\", 15], \"passed\": true}, {\"check\": \"control 1\", \"actual\": [\"stow\", \"wind\", 22], \"expected\": [\"stow\", \"wind\", 22], \"passed\": true}, {\"check\": \"control 2\", \"actual\": [\"track\", \"ok\", 8], \"expected\": [\"track\", \"ok\", 8], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.39,"exit_code":1,"observations":[{"actual":["track","ok",10],"check":"boundary: reading exactly max_age old","expected":["track","ok",10],"passed":true},{"actual":["track","ok",0],"check":"boundary: calm zero reading","expected":["track","ok",0],"passed":true},{"actual":["track","ok",15],"check":"boundary: wind at stow limit","expected":["stow","wind",15],"passed":false},{"actual":["track","ok",17.6],"check":"regression: reading just below limit","expected":["track","ok",17.6],"passed":true},{"actual":["track","ok",15],"check":"regression: stow threshold","expected":["stow","wind",15],"passed":false},{"actual":["stow","wind",22],"check":"control 1","expected":["stow","wind",22],"passed":true},{"actual":["track","ok",8],"check":"control 2","expected":["track","ok",8],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary: reading exactly max_age old\", \"actual\": [\"track\", \"ok\", 10], \"expected\": [\"track\", \"ok\", 10], \"passed\": true}, {\"check\": \"boundary: calm zero reading\", \"actual\": [\"track\", \"ok\", 0], \"expected\": [\"track\", \"ok\", 0], \"passed\": true}, {\"check\": \"boundary: wind at stow limit\", \"actual\": [\"track\", \"ok\", 15], \"expected\": [\"stow\", \"wind\", 15], \"passed\": false}, {\"check\": \"regression: reading just below limit\", \"actual\": [\"track\", \"ok\", 17.6], \"expected\": [\"track\", \"ok\", 17.6], \"passed\": true}, {\"check\": \"regression: stow threshold\", \"actual\": [\"track\", \"ok\", 15], \"expected\": [\"stow\", \"wind\", 15], \"passed\": false}, {\"check\": \"control 1\", \"actual\": [\"stow\", \"wind\", 22], \"expected\": [\"stow\", \"wind\", 22], \"passed\": true}, {\"check\": \"control 2\", \"actual\": [\"track\", \"ok\", 8], \"expected\": [\"track\", \"ok\", 8], \"passed\": true}], \"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."}}