{"abstract":"Fusion weights change when an equivalent sensor representation changes units.","category":"Sensor fusion consistency","checks":6,"contract":"For affine sensor calibration y=g*x+b with deterministic integer gain and offset, return calibrated mean and variance [g*x+b, g*g*r]. Raw variance r nonnegative.","contract_signature":"x, r, gain, offset","evaluation_group":"model-272908b777ec59c2","failed_approach":"Multiplying variance by absolute gain only accounts for standard-deviation scaling.","family":"z-sensor_fusion-calibration-noise","id":"FA-12086","implementations":{"attempt":{"sha256":"e435f712e99f644bfa3336feb82beb53d73b41b0a942160a967ef54ad5b13f51","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(x, r, gain, offset):\n    return [gain*x+offset,abs(gain)*r]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('gain greater than one', solve(N,N,2,3), [2*N+3,4*N])\ncheck('negative gain', solve(N,N,-3,1), [1-3*N,9*N])\ncheck('offset is deterministic', solve(N,N,1,100*N), [101*N,N])\ncheck('zero gain', solve(N,N,0,7), [7,0])\ncheck('noise free source', solve(N,0,3,N), [4*N,0])\ncheck('negative raw reading', solve(-N,N,2,-N), [-3*N,4*N])\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":"c88f8d870695ea99ab4fa433c84a6833141680af7cf646d55145f30b764d2953","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(x, r, gain, offset):\n    return [gain*x+offset,r]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('gain greater than one', solve(N,N,2,3), [2*N+3,4*N])\ncheck('negative gain', solve(N,N,-3,1), [1-3*N,9*N])\ncheck('offset is deterministic', solve(N,N,1,100*N), [101*N,N])\ncheck('zero gain', solve(N,N,0,7), [7,0])\ncheck('noise free source', solve(N,0,3,N), [4*N,0])\ncheck('negative raw reading', solve(-N,N,2,-N), [-3*N,4*N])\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":"Exact small scalar or two-axis models; no nonlinear dynamics, numerical conditioning, or real sensor noise simulation. 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":"z-sensor_fusion-calibration-noise","generated_at":"2026-09-29T14:38:53.676775+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Deterministic sensor-fusion model isolating one consistency contract; no hardware or production estimator is simulated.","root_cause":"Affine calibration transforms the mean but not covariance.","sha256":"e236fe5e78593eb323f274fdf2bb906218afa7b1d74d4389a3ab6b8286daa40f","title":"Calibration scales measurements but leaves their variances in raw units · 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":42.898,"exit_code":1,"observations":[{"actual":[5,2],"check":"gain greater than one","expected":[5,4],"passed":false},{"actual":[-2,3],"check":"negative gain","expected":[-2,9],"passed":false},{"actual":[101,1],"check":"offset is deterministic","expected":[101,1],"passed":true},{"actual":[7,0],"check":"zero gain","expected":[7,0],"passed":true},{"actual":[4,0],"check":"noise free source","expected":[4,0],"passed":true},{"actual":[-3,2],"check":"negative raw reading","expected":[-3,4],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"gain greater than one\", \"actual\": [5, 2], \"expected\": [5, 4], \"passed\": false}, {\"check\": \"negative gain\", \"actual\": [-2, 3], \"expected\": [-2, 9], \"passed\": false}, {\"check\": \"offset is deterministic\", \"actual\": [101, 1], \"expected\": [101, 1], \"passed\": true}, {\"check\": \"zero gain\", \"actual\": [7, 0], \"expected\": [7, 0], \"passed\": true}, {\"check\": \"noise free source\", \"actual\": [4, 0], \"expected\": [4, 0], \"passed\": true}, {\"check\": \"negative raw reading\", \"actual\": [-3, 2], \"expected\": [-3, 4], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.223,"exit_code":1,"observations":[{"actual":[5,1],"check":"gain greater than one","expected":[5,4],"passed":false},{"actual":[-2,1],"check":"negative gain","expected":[-2,9],"passed":false},{"actual":[101,1],"check":"offset is deterministic","expected":[101,1],"passed":true},{"actual":[7,1],"check":"zero gain","expected":[7,0],"passed":false},{"actual":[4,0],"check":"noise free source","expected":[4,0],"passed":true},{"actual":[-3,1],"check":"negative raw reading","expected":[-3,4],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"gain greater than one\", \"actual\": [5, 1], \"expected\": [5, 4], \"passed\": false}, {\"check\": \"negative gain\", \"actual\": [-2, 1], \"expected\": [-2, 9], \"passed\": false}, {\"check\": \"offset is deterministic\", \"actual\": [101, 1], \"expected\": [101, 1], \"passed\": true}, {\"check\": \"zero gain\", \"actual\": [7, 1], \"expected\": [7, 0], \"passed\": false}, {\"check\": \"noise free source\", \"actual\": [4, 0], \"expected\": [4, 0], \"passed\": true}, {\"check\": \"negative raw reading\", \"actual\": [-3, 1], \"expected\": [-3, 4], \"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."}}