{"abstract":"Multiplying row sums mixes each sample through unrelated gains.","category":"Audio channel mixing","checks":4,"contract":"Matrix rows are output channels and columns are input channels. Multiply one sample frame by the row-oriented routing matrix.","evaluation_group":"xaud-route-channel-matrix","failed_approach":"Transposing the routing matrix reverses input/output channel roles.","family":"xaud-route-channel-matrix","id":"FA-10941","implementations":{"attempt":{"sha256":"7882962f683226901908c60501616c4d953d9cc96c0b28ff997190f75e081647","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(frame, matrix):\n    return [sum(sample*gain for sample,gain in zip(frame,row)) for row in zip(*matrix)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2], [[1, 0], [0.5, 0.5]])),[1, 1.5])\ncheck('fixture 2',solve(*([2, 4], [[0, 1], [1, 0]])),[4, 2])\ncheck('fixture 3',solve(*([1, 2], [[1, 1]])),[3])\ncheck('fixture 4',solve(*([0, 0], [[1, 0], [0, 1]])),[0, 0])\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":"9fa8f20b945816ab3fca1c5c85b7aa9f8b7a98e643ae1f7355ce2e2a6cea5c93","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(frame, matrix):\n    return [sum(frame)*sum(row) for row in matrix]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2], [[1, 0], [0.5, 0.5]])),[1, 1.5])\ncheck('fixture 2',solve(*([2, 4], [[0, 1], [1, 0]])),[4, 2])\ncheck('fixture 3',solve(*([1, 2], [[1, 1]])),[3])\ncheck('fixture 4',solve(*([0, 0], [[1, 0], [0, 1]])),[0, 0])\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":"c556616b1cb516aaa2b1bd6e18ac900ef7d8d00ca433efd6a9b7c26d79896e1d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(frame, matrix):\n    return [sum(sample*gain for sample,gain in zip(frame,row)) for row in matrix]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2], [[1, 0], [0.5, 0.5]])),[1, 1.5])\ncheck('fixture 2',solve(*([2, 4], [[0, 1], [1, 0]])),[4, 2])\ncheck('fixture 3',solve(*([1, 2], [[1, 1]])),[3])\ncheck('fixture 4',solve(*([0, 0], [[1, 0], [0, 1]])),[0, 0])\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":" 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":"xaud-route-channel-matrix","generated_at":"2026-09-29T14:38:43.594841+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","repair":"Apply the explicit PCM/playback contract: Matrix rows are output channels and columns are input channels. Multiply one sample frame by the row-oriented routing matrix.","root_cause":"Multiplying row sums mixes each sample through unrelated gains.","sha256":"a69d3445a02334dab515aba22d4dbf6a251cca047f303421ba6811467b255cd9","title":"Route channel matrix · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.531,"exit_code":1,"observations":[{"actual":[2.0,1.0],"check":"fixture 1","expected":[1,1.5],"passed":false},{"actual":[4,2],"check":"fixture 2","expected":[4,2],"passed":true},{"actual":[1,1],"check":"fixture 3","expected":[3],"passed":false},{"actual":[0,0],"check":"fixture 4","expected":[0,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [2.0, 1.0], \"expected\": [1, 1.5], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [4, 2], \"expected\": [4, 2], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [1, 1], \"expected\": [3], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.633,"exit_code":1,"observations":[{"actual":[3,3.0],"check":"fixture 1","expected":[1,1.5],"passed":false},{"actual":[6,6],"check":"fixture 2","expected":[4,2],"passed":false},{"actual":[6],"check":"fixture 3","expected":[3],"passed":false},{"actual":[0,0],"check":"fixture 4","expected":[0,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [3, 3.0], \"expected\": [1, 1.5], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [6, 6], \"expected\": [4, 2], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [6], \"expected\": [3], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.684,"exit_code":0,"observations":[{"actual":[1,1.5],"check":"fixture 1","expected":[1,1.5],"passed":true},{"actual":[4,2],"check":"fixture 2","expected":[4,2],"passed":true},{"actual":[3],"check":"fixture 3","expected":[3],"passed":true},{"actual":[0,0],"check":"fixture 4","expected":[0,0],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1, 1.5], \"expected\": [1, 1.5], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [4, 2], \"expected\": [4, 2], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [3], \"expected\": [3], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}