{
 "tool": "mannings-n",
 "toolVersion": "1.1.0",
 "methods": [
  "cowan 1.0.0",
  "composite-n 1.0.0"
 ],
 "commit": "ab22876",
 "date": "2026-11-04",
 "summary": "11 of 11 cases (15 values) within tolerance against USGS WSP 2339, Hand calculation of the published equations.",
 "note": "Generated by _workspace/tools/hh_verification.mjs from the fixtures; commit = code verified.",
 "cases": [
  {
   "id": "WSP2339-T4-XS1",
   "what": "Channel: base n plus adjustments (cross section 1)",
   "reference": "USGS WSP 2339 (published example)",
   "compared": 1,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "WSP2339-T4-XS2",
   "what": "Channel: base n plus adjustments (cross section 2)",
   "reference": "USGS WSP 2339 (published example)",
   "compared": 1,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "WSP2339-T4-XS3-2",
   "what": "Channel: base n plus adjustments (cross section 3, subsection 2)",
   "reference": "USGS WSP 2339 (published example)",
   "compared": 1,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "WSP2339-T4-XS3-1",
   "what": "Flood plain: base n plus adjustments (cross section 3, subsection 1)",
   "reference": "USGS WSP 2339 (published example)",
   "compared": 1,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "WSP2339-T4-XS3-3",
   "what": "Flood plain: base n plus adjustments (cross section 3, subsection 3)",
   "reference": "USGS WSP 2339 (published example)",
   "compared": 1,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "ARITH-COMPOSITE-HORTON-2",
   "what": "Two parts, concrete bottom 10 ft at n 0.013 and grass banks 6 ft at n 0.035, Horton-Einstein",
   "reference": "Hand calculation of the published equations (published example)",
   "compared": 2,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "ARITH-COMPOSITE-PAVLOVSKII-2",
   "what": "Same two parts, Pavlovskii",
   "reference": "Hand calculation of the published equations (published example)",
   "compared": 2,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "ARITH-COMPOSITE-HORTON-3",
   "what": "Three parts, 4 ft at n 0.012, 12 ft at n 0.030, 4 ft at n 0.045, Horton-Einstein",
   "reference": "Hand calculation of the published equations (published example)",
   "compared": 2,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "ARITH-COMPOSITE-EQUAL",
   "what": "Two parts with the same n: the composite equals that n",
   "reference": "Hand calculation of the published equations (published example)",
   "compared": 2,
   "maxDiff": "0.00 %",
   "pass": true
  },
  {
   "id": "ARITH-COMPOSITE-ONE-PART",
   "what": "One part only: refused, a composite needs at least two parts",
   "reference": "Hand calculation of the published equations (published example)",
   "compared": 1,
   "maxDiff": "both refuse",
   "pass": true
  },
  {
   "id": "ARITH-COMPOSITE-ZERO-LENGTH",
   "what": "A part with zero length: refused",
   "reference": "Hand calculation of the published equations (published example)",
   "compared": 1,
   "maxDiff": "both refuse",
   "pass": true
  }
 ]
}