{"abstract":"A 10 cm coaster is worked to 20 cm.","category":"Knitting and sewing pattern grading","checks":8,"contract":"Base stitches per round: sc 6, hdc 8, dc 12 (others -> \"error: stitch\"). Each round adds one round height to the radius. rounds = ceiling(diameter/(2*height)). Round k has base*k stitches. Return [rounds, stitches in last round, total stitches base*rounds*(rounds+1)/2].","evaluation_group":"w2-knitting_and_sewing_pattern_grading-crochet-circle","failed_approach":"Rounding to nearest can stop short of the target diameter.","family":"w2-knitting_and_sewing_pattern_grading-crochet-circle-radius-per-round","id":"FA-97641","implementations":{"attempt":{"sha256":"479c37e138c1e53e87ff14f4d72fafbab8473a2e7d30acee2f71a4e082f1a8e3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(stitch, diameter, round_height):\n    BASE = {'sc': 6, 'hdc': 8, 'dc': 12}\n    if stitch not in BASE:\n        return 'error: stitch'\n    h = Fraction(round_height)\n    rounds = math.floor(Fraction(diameter) / (2 * h) + Fraction(1, 2))\n    b = BASE[stitch]\n    return [rounds, b * rounds, b * rounds * (rounds + 1) // 2]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['coaster', ['sc', 10, '0.5'], [10, 60, 330]], ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['regression: radius per round', ['hdc', 12, '2'], [3, 24, 48]],\n  ['repair check: radius per round', ['sc', 20, '0.75'], [14, 84, 630]],\n  ['generated control 1', ['dc', 10, '1.5'], [4, 48, 120]],\n  ['generated control 2', ['hdc', 5, '0.75'], [4, 32, 80]],\n  ['generated control 3', ['sc', 10, '1.5'], [4, 24, 60]]],\n [['dc mat', ['dc', 30, '1.5'], [10, 120, 660]], ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['regression: radius per round', ['sc', 12, '0.5'], [12, 72, 468]],\n  ['repair check: radius per round', ['sc', 5, '2'], [2, 12, 18]],\n  ['generated control 1', ['dc', 12, '2'], [3, 36, 72]],\n  ['generated control 2', ['hdc', 15, '1'], [8, 64, 288]],\n  ['generated control 3', ['tr', 20, '0.5'], 'error: stitch']],\n [['treble unknown', ['tr', 10, '1'], 'error: stitch'], ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['regression: radius per round', ['dc', 15, '0.5'], [15, 180, 1440]],\n  ['repair check: radius per round', ['hdc', 10, '1.5'], [4, 32, 80]],\n  ['generated control 1', ['hdc', 12, '0.5'], [12, 96, 624]],\n  ['generated control 2', ['hdc', 30, '1'], [15, 120, 960]],\n  ['generated control 3', ['sc', 10, '1.5'], [4, 24, 60]]],\n [['coaster', ['sc', 10, '0.5'], [10, 60, 330]], ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['regression: radius per round', ['dc', 10, '0.5'], [10, 120, 660]],\n  ['repair check: radius per round', ['hdc', 10, '1.5'], [4, 32, 80]],\n  ['generated control 1', ['tr', 5, '2'], 'error: stitch'],\n  ['generated control 2', ['hdc', 15, '1.5'], [5, 40, 120]],\n  ['generated control 3', ['hdc', 20, '2'], [5, 40, 120]]],\n [['dc mat', ['dc', 30, '1.5'], [10, 120, 660]], ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['regression: radius per round', ['dc', 5, '2'], [2, 24, 36]],\n  ['repair check: radius per round', ['hdc', 20, '0.75'], [14, 112, 840]],\n  ['generated control 1', ['tr', 30, '2'], 'error: stitch'],\n  ['generated control 2', ['tr', 20, '2'], 'error: stitch'],\n  ['generated control 3', ['dc', 15, '1'], [8, 96, 432]]]]\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":"9e5e228cc1baac064674222860736aa1802ea32ac5d0672bf30c0239813349b5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(stitch, diameter, round_height):\n    BASE = {'sc': 6, 'hdc': 8, 'dc': 12}\n    if stitch not in BASE:\n        return 'error: stitch'\n    h = Fraction(round_height)\n    rounds = math.ceil(Fraction(diameter) / h)\n    b = BASE[stitch]\n    return [rounds, b * rounds, b * rounds * (rounds + 1) // 2]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['coaster', ['sc', 10, '0.5'], [10, 60, 330]], ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['regression: radius per round', ['hdc', 12, '2'], [3, 24, 48]],\n  ['repair check: radius per round', ['sc', 20, '0.75'], [14, 84, 630]],\n  ['generated control 1', ['dc', 10, '1.5'], [4, 48, 120]],\n  ['generated control 2', ['hdc', 5, '0.75'], [4, 32, 80]],\n  ['generated control 3', ['sc', 10, '1.5'], [4, 24, 60]]],\n [['dc mat', ['dc', 30, '1.5'], [10, 120, 660]], ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['regression: radius per round', ['sc', 12, '0.5'], [12, 72, 468]],\n  ['repair check: radius per round', ['sc', 5, '2'], [2, 12, 18]],\n  ['generated control 1', ['dc', 12, '2'], [3, 36, 72]],\n  ['generated control 2', ['hdc', 15, '1'], [8, 64, 288]],\n  ['generated control 3', ['tr', 20, '0.5'], 'error: stitch']],\n [['treble unknown', ['tr', 10, '1'], 'error: stitch'], ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['regression: radius per round', ['dc', 15, '0.5'], [15, 180, 1440]],\n  ['repair check: radius per round', ['hdc', 10, '1.5'], [4, 32, 80]],\n  ['generated control 1', ['hdc', 12, '0.5'], [12, 96, 624]],\n  ['generated control 2', ['hdc', 30, '1'], [15, 120, 960]],\n  ['generated control 3', ['sc', 10, '1.5'], [4, 24, 60]]],\n [['coaster', ['sc', 10, '0.5'], [10, 60, 330]], ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['regression: radius per round', ['dc', 10, '0.5'], [10, 120, 660]],\n  ['repair check: radius per round', ['hdc', 10, '1.5'], [4, 32, 80]],\n  ['generated control 1', ['tr', 5, '2'], 'error: stitch'],\n  ['generated control 2', ['hdc', 15, '1.5'], [5, 40, 120]],\n  ['generated control 3', ['hdc', 20, '2'], [5, 40, 120]]],\n [['dc mat', ['dc', 30, '1.5'], [10, 120, 660]], ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['regression: radius per round', ['dc', 5, '2'], [2, 24, 36]],\n  ['repair check: radius per round', ['hdc', 20, '0.75'], [14, 112, 840]],\n  ['generated control 1', ['tr', 30, '2'], 'error: stitch'],\n  ['generated control 2', ['tr', 20, '2'], 'error: stitch'],\n  ['generated control 3', ['dc', 15, '1'], [8, 96, 432]]]]\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":"3f383fa5cc369a64e57f55fc5a9c37b8e2c3a6d1b581e9f917d2f9215fa1621a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(stitch, diameter, round_height):\n    BASE = {'sc': 6, 'hdc': 8, 'dc': 12}\n    if stitch not in BASE:\n        return 'error: stitch'\n    h = Fraction(round_height)\n    rounds = math.ceil(Fraction(diameter) / (2 * h))\n    b = BASE[stitch]\n    return [rounds, b * rounds, b * rounds * (rounds + 1) // 2]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['coaster', ['sc', 10, '0.5'], [10, 60, 330]], ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['regression: radius per round', ['hdc', 12, '2'], [3, 24, 48]],\n  ['repair check: radius per round', ['sc', 20, '0.75'], [14, 84, 630]],\n  ['generated control 1', ['dc', 10, '1.5'], [4, 48, 120]],\n  ['generated control 2', ['hdc', 5, '0.75'], [4, 32, 80]],\n  ['generated control 3', ['sc', 10, '1.5'], [4, 24, 60]]],\n [['dc mat', ['dc', 30, '1.5'], [10, 120, 660]], ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['regression: radius per round', ['sc', 12, '0.5'], [12, 72, 468]],\n  ['repair check: radius per round', ['sc', 5, '2'], [2, 12, 18]],\n  ['generated control 1', ['dc', 12, '2'], [3, 36, 72]],\n  ['generated control 2', ['hdc', 15, '1'], [8, 64, 288]],\n  ['generated control 3', ['tr', 20, '0.5'], 'error: stitch']],\n [['treble unknown', ['tr', 10, '1'], 'error: stitch'], ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['regression: radius per round', ['dc', 15, '0.5'], [15, 180, 1440]],\n  ['repair check: radius per round', ['hdc', 10, '1.5'], [4, 32, 80]],\n  ['generated control 1', ['hdc', 12, '0.5'], [12, 96, 624]],\n  ['generated control 2', ['hdc', 30, '1'], [15, 120, 960]],\n  ['generated control 3', ['sc', 10, '1.5'], [4, 24, 60]]],\n [['coaster', ['sc', 10, '0.5'], [10, 60, 330]], ['dc mat', ['dc', 30, '1.5'], [10, 120, 660]],\n  ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['regression: radius per round', ['dc', 10, '0.5'], [10, 120, 660]],\n  ['repair check: radius per round', ['hdc', 10, '1.5'], [4, 32, 80]],\n  ['generated control 1', ['tr', 5, '2'], 'error: stitch'],\n  ['generated control 2', ['hdc', 15, '1.5'], [5, 40, 120]],\n  ['generated control 3', ['hdc', 20, '2'], [5, 40, 120]]],\n [['dc mat', ['dc', 30, '1.5'], [10, 120, 660]], ['treble unknown', ['tr', 10, '1'], 'error: stitch'],\n  ['coaster', ['sc', 10, '0.5'], [10, 60, 330]],\n  ['regression: radius per round', ['dc', 5, '2'], [2, 24, 36]],\n  ['repair check: radius per round', ['hdc', 20, '0.75'], [14, 112, 840]],\n  ['generated control 1', ['tr', 30, '2'], 'error: stitch'],\n  ['generated control 2', ['tr', 20, '2'], 'error: stitch'],\n  ['generated control 3', ['dc', 15, '1'], [8, 96, 432]]]]\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":"A deterministic toy contract stated in full here; it is a bounded teaching model, not an authoritative reference or standards implementation. 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-knitting_and_sewing_pattern_grading-crochet-circle-radius-per-round","generated_at":"2026-09-29T14:52:34.148168+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Amigurumi and rug patterns size flat circles by rounds of evenly spaced increases.","repair":"Divide the diameter by twice the round height and round up.","root_cause":"Each round is assumed to add its height to the diameter rather than the radius.","sha256":"fb0a2a9405dca6171c77f027142beb21d8a24b9327f03a22f92332e0e0d15a9e","title":"Flat crochet circle planner: radius per round · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":44.294,"exit_code":1,"observations":[{"actual":[10,60,330],"check":"coaster","expected":[10,60,330],"passed":true},{"actual":[10,120,660],"check":"dc mat","expected":[10,120,660],"passed":true},{"actual":"error: stitch","check":"treble unknown","expected":"error: stitch","passed":true},{"actual":[3,24,48],"check":"regression: radius per round","expected":[3,24,48],"passed":true},{"actual":[13,78,546],"check":"repair check: radius per round","expected":[14,84,630],"passed":false},{"actual":[3,36,72],"check":"generated control 1","expected":[4,48,120],"passed":false},{"actual":[3,24,48],"check":"generated control 2","expected":[4,32,80],"passed":false},{"actual":[3,18,36],"check":"generated control 3","expected":[4,24,60],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"coaster\", \"actual\": [10, 60, 330], \"expected\": [10, 60, 330], \"passed\": true}, {\"check\": \"dc mat\", \"actual\": [10, 120, 660], \"expected\": [10, 120, 660], \"passed\": true}, {\"check\": \"treble unknown\", \"actual\": \"error: stitch\", \"expected\": \"error: stitch\", \"passed\": true}, {\"check\": \"regression: radius per round\", \"actual\": [3, 24, 48], \"expected\": [3, 24, 48], \"passed\": true}, {\"check\": \"repair check: radius per round\", \"actual\": [13, 78, 546], \"expected\": [14, 84, 630], \"passed\": false}, {\"check\": \"generated control 1\", \"actual\": [3, 36, 72], \"expected\": [4, 48, 120], \"passed\": false}, {\"check\": \"generated control 2\", \"actual\": [3, 24, 48], \"expected\": [4, 32, 80], \"passed\": false}, {\"check\": \"generated control 3\", \"actual\": [3, 18, 36], \"expected\": [4, 24, 60], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.761,"exit_code":1,"observations":[{"actual":[20,120,1260],"check":"coaster","expected":[10,60,330],"passed":false},{"actual":[20,240,2520],"check":"dc mat","expected":[10,120,660],"passed":false},{"actual":"error: stitch","check":"treble unknown","expected":"error: stitch","passed":true},{"actual":[6,48,168],"check":"regression: radius per round","expected":[3,24,48],"passed":false},{"actual":[27,162,2268],"check":"repair check: radius per round","expected":[14,84,630],"passed":false},{"actual":[7,84,336],"check":"generated control 1","expected":[4,48,120],"passed":false},{"actual":[7,56,224],"check":"generated control 2","expected":[4,32,80],"passed":false},{"actual":[7,42,168],"check":"generated control 3","expected":[4,24,60],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"coaster\", \"actual\": [20, 120, 1260], \"expected\": [10, 60, 330], \"passed\": false}, {\"check\": \"dc mat\", \"actual\": [20, 240, 2520], \"expected\": [10, 120, 660], \"passed\": false}, {\"check\": \"treble unknown\", \"actual\": \"error: stitch\", \"expected\": \"error: stitch\", \"passed\": true}, {\"check\": \"regression: radius per round\", \"actual\": [6, 48, 168], \"expected\": [3, 24, 48], \"passed\": false}, {\"check\": \"repair check: radius per round\", \"actual\": [27, 162, 2268], \"expected\": [14, 84, 630], \"passed\": false}, {\"check\": \"generated control 1\", \"actual\": [7, 84, 336], \"expected\": [4, 48, 120], \"passed\": false}, {\"check\": \"generated control 2\", \"actual\": [7, 56, 224], \"expected\": [4, 32, 80], \"passed\": false}, {\"check\": \"generated control 3\", \"actual\": [7, 42, 168], \"expected\": [4, 24, 60], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":42.256,"exit_code":0,"observations":[{"actual":[10,60,330],"check":"coaster","expected":[10,60,330],"passed":true},{"actual":[10,120,660],"check":"dc mat","expected":[10,120,660],"passed":true},{"actual":"error: stitch","check":"treble unknown","expected":"error: stitch","passed":true},{"actual":[3,24,48],"check":"regression: radius per round","expected":[3,24,48],"passed":true},{"actual":[14,84,630],"check":"repair check: radius per round","expected":[14,84,630],"passed":true},{"actual":[4,48,120],"check":"generated control 1","expected":[4,48,120],"passed":true},{"actual":[4,32,80],"check":"generated control 2","expected":[4,32,80],"passed":true},{"actual":[4,24,60],"check":"generated control 3","expected":[4,24,60],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"coaster\", \"actual\": [10, 60, 330], \"expected\": [10, 60, 330], \"passed\": true}, {\"check\": \"dc mat\", \"actual\": [10, 120, 660], \"expected\": [10, 120, 660], \"passed\": true}, {\"check\": \"treble unknown\", \"actual\": \"error: stitch\", \"expected\": \"error: stitch\", \"passed\": true}, {\"check\": \"regression: radius per round\", \"actual\": [3, 24, 48], \"expected\": [3, 24, 48], \"passed\": true}, {\"check\": \"repair check: radius per round\", \"actual\": [14, 84, 630], \"expected\": [14, 84, 630], \"passed\": true}, {\"check\": \"generated control 1\", \"actual\": [4, 48, 120], \"expected\": [4, 48, 120], \"passed\": true}, {\"check\": \"generated control 2\", \"actual\": [4, 32, 80], \"expected\": [4, 32, 80], \"passed\": true}, {\"check\": \"generated control 3\", \"actual\": [4, 24, 60], \"expected\": [4, 24, 60], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}