{"abstract":"Negative rotations report more clearance than the hub height.","category":"Solar tracker geometry","checks":7,"contract":"Hub height h and module width w in mm. Maximum rotation keeps the low edge at least clear above flat ground: asin((h - clear)/(w/2)), 90 when that ratio >= 1, 0 when <= 0. The command is theta clamped to +-max. Reported clearance is h - (w/2)|sin cmd| minus the ground rise under the low edge, side*(w/2)cos(cmd)tan(slope), where side is the sign of cmd or, at 0, the sign of slope (>= 0 counts positive). Return [cmd rounded 3, clearance rounded 1].","evaluation_group":"w2-solar_tracker_geometry-edge-ground-clearance","failed_approach":"Taking the sine of the angle in degrees gives meaningless drops.","family":"w2-solar_tracker_geometry-edge-ground-clearance-edge-drop-magnitude","id":"FA-93756","implementations":{"attempt":{"sha256":"7ae72bd0476f55e48513d6966af71ebe1e7bee551f86db79afc90d88201947db","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(theta, h, w, clear, slope):\n    half = w / 2\n    lim = (h - clear) / half\n    if lim >= 1:\n        amax = 90.0\n    elif lim <= 0:\n        amax = 0.0\n    else:\n        amax = math.degrees(math.asin(lim))\n    cmd = max(-amax, min(amax, theta))\n    r = math.radians(cmd)\n    low = h - half * abs(math.sin(abs(cmd)))\n    if cmd != 0:\n        side = 1 if cmd > 0 else -1\n    else:\n        side = 1 if slope >= 0 else -1\n    ground = side * half * math.cos(r) * math.tan(math.radians(slope))\n    return [round(cmd, 3), round(low - ground, 1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-45, 1200, 2384, 300, 0], [-45, 357.1]],\n  ['regression: edge drop magnitude (partial repair)', [-60, 1500, 1133, 500, 0], [-60, 1009.4]],\n  ['control 1', [-45, 1200, 2384, 300, -10], [-45, 208.5]],\n  ['control 2', [0, 1500, 1133, 2600, -10], [-0.0, 1400.1]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 1133, 1300, 0], [-20.674, 1300.0]],\n  ['regression: edge drop magnitude (partial repair)', [60, 2000, 1133, 500, 0], [60, 1509.4]],\n  ['control 1', [20, 2000, 2256, 500, -10], [20, 1801.1]],\n  ['control 2', [0, 2500, 2000, 300, -5], [0, 2412.5]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 2256, 300, 0], [-30, 936.0]],\n  ['regression: edge drop magnitude (partial repair)', [45, 1200, 2256, 300, 0], [45, 402.4]],\n  ['control 1', [60, 2500, 1133, 1300, 8], [60, 1969.6]],\n  ['control 2', [20, 1200, 2000, 1300, 3], [-0.0, 1147.6]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 2384, 500, -5], [-30, 813.7]],\n  ['regression: edge drop magnitude (partial repair)', [45, 2000, 4000, 500, 0], [45, 585.8]],\n  ['control 1', [60, 2000, 1133, 2600, -5], [-0.0, 1950.4]],\n  ['control 2', [45, 1200, 1133, 300, 3], [45, 778.4]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-60, 2500, 2256, 300, -10], [-60, 1423.7]],\n  ['regression: edge drop magnitude (partial repair)', [20, 2500, 2384, 300, -10], [20, 2289.8]],\n  ['control 1', [-30, 1500, 2384, 500, -5], [-30, 813.7]],\n  ['control 2', [-30, 1200, 4000, 2600, 0], [-0.0, 1200.0]]]]\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":"4bc29f8b86903184ea1a89da85ace5eca58d29181d84213b58c122b706be686b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(theta, h, w, clear, slope):\n    half = w / 2\n    lim = (h - clear) / half\n    if lim >= 1:\n        amax = 90.0\n    elif lim <= 0:\n        amax = 0.0\n    else:\n        amax = math.degrees(math.asin(lim))\n    cmd = max(-amax, min(amax, theta))\n    r = math.radians(cmd)\n    low = h - half * math.sin(r)\n    if cmd != 0:\n        side = 1 if cmd > 0 else -1\n    else:\n        side = 1 if slope >= 0 else -1\n    ground = side * half * math.cos(r) * math.tan(math.radians(slope))\n    return [round(cmd, 3), round(low - ground, 1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-45, 1200, 2384, 300, 0], [-45, 357.1]],\n  ['regression: edge drop magnitude (partial repair)', [-60, 1500, 1133, 500, 0], [-60, 1009.4]],\n  ['control 1', [-45, 1200, 2384, 300, -10], [-45, 208.5]],\n  ['control 2', [0, 1500, 1133, 2600, -10], [-0.0, 1400.1]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 1133, 1300, 0], [-20.674, 1300.0]],\n  ['regression: edge drop magnitude (partial repair)', [60, 2000, 1133, 500, 0], [60, 1509.4]],\n  ['control 1', [20, 2000, 2256, 500, -10], [20, 1801.1]],\n  ['control 2', [0, 2500, 2000, 300, -5], [0, 2412.5]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 2256, 300, 0], [-30, 936.0]],\n  ['regression: edge drop magnitude (partial repair)', [45, 1200, 2256, 300, 0], [45, 402.4]],\n  ['control 1', [60, 2500, 1133, 1300, 8], [60, 1969.6]],\n  ['control 2', [20, 1200, 2000, 1300, 3], [-0.0, 1147.6]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 2384, 500, -5], [-30, 813.7]],\n  ['regression: edge drop magnitude (partial repair)', [45, 2000, 4000, 500, 0], [45, 585.8]],\n  ['control 1', [60, 2000, 1133, 2600, -5], [-0.0, 1950.4]],\n  ['control 2', [45, 1200, 1133, 300, 3], [45, 778.4]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-60, 2500, 2256, 300, -10], [-60, 1423.7]],\n  ['regression: edge drop magnitude (partial repair)', [20, 2500, 2384, 300, -10], [20, 2289.8]],\n  ['control 1', [-30, 1500, 2384, 500, -5], [-30, 813.7]],\n  ['control 2', [-30, 1200, 4000, 2600, 0], [-0.0, 1200.0]]]]\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"},"fixed":{"sha256":"dea91d675c8d7cba3907b447c6bcd8b736de61830f80e5b390aaea5318376349","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(theta, h, w, clear, slope):\n    half = w / 2\n    lim = (h - clear) / half\n    if lim >= 1:\n        amax = 90.0\n    elif lim <= 0:\n        amax = 0.0\n    else:\n        amax = math.degrees(math.asin(lim))\n    cmd = max(-amax, min(amax, theta))\n    r = math.radians(cmd)\n    low = h - half * abs(math.sin(r))\n    if cmd != 0:\n        side = 1 if cmd > 0 else -1\n    else:\n        side = 1 if slope >= 0 else -1\n    ground = side * half * math.cos(r) * math.tan(math.radians(slope))\n    return [round(cmd, 3), round(low - ground, 1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-45, 1200, 2384, 300, 0], [-45, 357.1]],\n  ['regression: edge drop magnitude (partial repair)', [-60, 1500, 1133, 500, 0], [-60, 1009.4]],\n  ['control 1', [-45, 1200, 2384, 300, -10], [-45, 208.5]],\n  ['control 2', [0, 1500, 1133, 2600, -10], [-0.0, 1400.1]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 1133, 1300, 0], [-20.674, 1300.0]],\n  ['regression: edge drop magnitude (partial repair)', [60, 2000, 1133, 500, 0], [60, 1509.4]],\n  ['control 1', [20, 2000, 2256, 500, -10], [20, 1801.1]],\n  ['control 2', [0, 2500, 2000, 300, -5], [0, 2412.5]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 2256, 300, 0], [-30, 936.0]],\n  ['regression: edge drop magnitude (partial repair)', [45, 1200, 2256, 300, 0], [45, 402.4]],\n  ['control 1', [60, 2500, 1133, 1300, 8], [60, 1969.6]],\n  ['control 2', [20, 1200, 2000, 1300, 3], [-0.0, 1147.6]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-30, 1500, 2384, 500, -5], [-30, 813.7]],\n  ['regression: edge drop magnitude (partial repair)', [45, 2000, 4000, 500, 0], [45, 585.8]],\n  ['control 1', [60, 2000, 1133, 2600, -5], [-0.0, 1950.4]],\n  ['control 2', [45, 1200, 1133, 300, 3], [45, 778.4]]],\n [['normal: rotation limited by clearance', [60, 1500, 2256, 500, 0], [60, 523.1]],\n  ['boundary: hub below required clearance', [30, 1200, 2000, 1300, 0], [-0.0, 1200.0]],\n  ['boundary: flat on sloped ground', [0, 1500, 2000, 500, -5], [0, 1412.5]],\n  ['regression: edge drop magnitude', [-60, 2500, 2256, 300, -10], [-60, 1423.7]],\n  ['regression: edge drop magnitude (partial repair)', [20, 2500, 2384, 300, -10], [20, 2289.8]],\n  ['control 1', [-30, 1500, 2384, 500, -5], [-30, 813.7]],\n  ['control 2', [-30, 1200, 4000, 2600, 0], [-0.0, 1200.0]]]]\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-edge-ground-clearance-edge-drop-magnitude","generated_at":"2026-09-29T14:51:58.099237+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.","repair":"Use |sin(cmd)| for the low edge.","root_cause":"The edge drop uses the signed sine.","sha256":"7c65dc31ca4b882f505893fc315db9651b2c9c5fe958b995a1ebee613f1ce145","title":"Module edge ground clearance limit: edge drop magnitude · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":45.66,"exit_code":1,"observations":[{"actual":[60,1156.2],"check":"normal: rotation limited by clearance","expected":[60,523.1],"passed":false},{"actual":[-0.0,1200.0],"check":"boundary: hub below required clearance","expected":[-0.0,1200.0],"passed":true},{"actual":[0,1412.5],"check":"boundary: flat on sloped ground","expected":[0,1412.5],"passed":true},{"actual":[-45,185.7],"check":"regression: edge drop magnitude","expected":[-45,357.1],"passed":false},{"actual":[-60,1327.3],"check":"regression: edge drop magnitude (partial repair)","expected":[-60,1009.4],"passed":false},{"actual":[-45,37.1],"check":"control 1","expected":[-45,208.5],"passed":false},{"actual":[-0.0,1400.1],"check":"control 2","expected":[-0.0,1400.1],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal: rotation limited by clearance\", \"actual\": [60, 1156.2], \"expected\": [60, 523.1], \"passed\": false}, {\"check\": \"boundary: hub below required clearance\", \"actual\": [-0.0, 1200.0], \"expected\": [-0.0, 1200.0], \"passed\": true}, {\"check\": \"boundary: flat on sloped ground\", \"actual\": [0, 1412.5], \"expected\": [0, 1412.5], \"passed\": true}, {\"check\": \"regression: edge drop magnitude\", \"actual\": [-45, 185.7], \"expected\": [-45, 357.1], \"passed\": false}, {\"check\": \"regression: edge drop magnitude (partial repair)\", \"actual\": [-60, 1327.3], \"expected\": [-60, 1009.4], \"passed\": false}, {\"check\": \"control 1\", \"actual\": [-45, 37.1], \"expected\": [-45, 208.5], \"passed\": false}, {\"check\": \"control 2\", \"actual\": [-0.0, 1400.1], \"expected\": [-0.0, 1400.1], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.168,"exit_code":1,"observations":[{"actual":[60,523.1],"check":"normal: rotation limited by clearance","expected":[60,523.1],"passed":true},{"actual":[-0.0,1200.0],"check":"boundary: hub below required clearance","expected":[-0.0,1200.0],"passed":true},{"actual":[0,1412.5],"check":"boundary: flat on sloped ground","expected":[0,1412.5],"passed":true},{"actual":[-45,2042.9],"check":"regression: edge drop magnitude","expected":[-45,357.1],"passed":false},{"actual":[-60,1990.6],"check":"regression: edge drop magnitude (partial repair)","expected":[-60,1009.4],"passed":false},{"actual":[-45,1894.3],"check":"control 1","expected":[-45,208.5],"passed":false},{"actual":[-0.0,1400.1],"check":"control 2","expected":[-0.0,1400.1],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal: rotation limited by clearance\", \"actual\": [60, 523.1], \"expected\": [60, 523.1], \"passed\": true}, {\"check\": \"boundary: hub below required clearance\", \"actual\": [-0.0, 1200.0], \"expected\": [-0.0, 1200.0], \"passed\": true}, {\"check\": \"boundary: flat on sloped ground\", \"actual\": [0, 1412.5], \"expected\": [0, 1412.5], \"passed\": true}, {\"check\": \"regression: edge drop magnitude\", \"actual\": [-45, 2042.9], \"expected\": [-45, 357.1], \"passed\": false}, {\"check\": \"regression: edge drop magnitude (partial repair)\", \"actual\": [-60, 1990.6], \"expected\": [-60, 1009.4], \"passed\": false}, {\"check\": \"control 1\", \"actual\": [-45, 1894.3], \"expected\": [-45, 208.5], \"passed\": false}, {\"check\": \"control 2\", \"actual\": [-0.0, 1400.1], \"expected\": [-0.0, 1400.1], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.609,"exit_code":0,"observations":[{"actual":[60,523.1],"check":"normal: rotation limited by clearance","expected":[60,523.1],"passed":true},{"actual":[-0.0,1200.0],"check":"boundary: hub below required clearance","expected":[-0.0,1200.0],"passed":true},{"actual":[0,1412.5],"check":"boundary: flat on sloped ground","expected":[0,1412.5],"passed":true},{"actual":[-45,357.1],"check":"regression: edge drop magnitude","expected":[-45,357.1],"passed":true},{"actual":[-60,1009.4],"check":"regression: edge drop magnitude (partial repair)","expected":[-60,1009.4],"passed":true},{"actual":[-45,208.5],"check":"control 1","expected":[-45,208.5],"passed":true},{"actual":[-0.0,1400.1],"check":"control 2","expected":[-0.0,1400.1],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal: rotation limited by clearance\", \"actual\": [60, 523.1], \"expected\": [60, 523.1], \"passed\": true}, {\"check\": \"boundary: hub below required clearance\", \"actual\": [-0.0, 1200.0], \"expected\": [-0.0, 1200.0], \"passed\": true}, {\"check\": \"boundary: flat on sloped ground\", \"actual\": [0, 1412.5], \"expected\": [0, 1412.5], \"passed\": true}, {\"check\": \"regression: edge drop magnitude\", \"actual\": [-45, 357.1], \"expected\": [-45, 357.1], \"passed\": true}, {\"check\": \"regression: edge drop magnitude (partial repair)\", \"actual\": [-60, 1009.4], \"expected\": [-60, 1009.4], \"passed\": true}, {\"check\": \"control 1\", \"actual\": [-45, 208.5], \"expected\": [-45, 208.5], \"passed\": true}, {\"check\": \"control 2\", \"actual\": [-0.0, 1400.1], \"expected\": [-0.0, 1400.1], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}