dsh-geodesy
Geodesic math toolbox for DeepSeek Harness (dsh): great-circle distances, bearings, destination points, and DMS coordinate parsing — all as local, deterministic tools with zero runtime dependencies.
> 中文简介：dsh 插件「大地测量工具箱」——大圆距离、方位角、目的地推算与 DMS 坐标解析四个纯计算工具，零运行时依赖。专治大模型手算球面距离/坐标换算的常见错误（弧度与角度混用、忘记地球半径、经纬度顺序颠倒等）。
Why
LLMs reliably fumble geodesic math: they mix up latitude/longitude order, use the wrong Earth radius, forget degrees→radians, and botch DMS conversions. This plugin moves that math out of the model's head and into exact spherical trigonometry:
geo_distance— great-circle distance (haversine) between two points, with initial/final bearings and the 16-wind compass direction; results in km, m, mi, or nmigeo_bearing— initial & final great-circle bearings plus the great-circle midpoint of two pointsgeo_destination— the direct geodesic problem: given a start point, bearing and distance, compute the destination (with a round-trip distance check)coord_parse— parse and validate coordinate strings (decimal, DMS, suffixes, pairs) and convert them to decimal degrees + formatted DMS
All math uses the IUGG mean Earth radius 6371.0088 km (configurable via the plugin radiusKm option, e.g. for lunar or planetary calculations).
Install
dsh plugin --profile web add github:TYEclipse/dsh-geodesyRequires pnpm on your PATH. Then restart the profile's services (or dsh restart web).
Usage
Ask the agent questions that involve Earth-surface math; it will call the tools automatically:
- "What is the great-circle distance from Beijing to Shanghai?"
- "Which direction is New York from London, and where is the midpoint?"
- "I'm 200 km due east of Paris — where am I?"
- "Parse 37°46′30″N, 122°25′8.4″W into decimal degrees."
Examples
geo_distance — Beijing (39.9042, 116.4074) → Shanghai (31.2304, 121.4737):
{
"valid": true,
"unit": "km",
"distance": 1067.311645,
"kilometers": 1067.311645,
"miles": 663.196709,
"nauticalMiles": 576.302184,
"initialBearing": 153.072675,
"finalBearing": 156.029266,
"compass": "SSE"
}coord_parse:
{
"valid": true,
"input": "37°46′30″N, 122°25′8.4″W",
"latitude": 37.775,
"longitude": -122.419,
"latDms": "37°46′30″N",
"lonDms": "122°25′8.4″W"
}Coordinate input formats
coord_parse accepts, deterministically:
| Input | Meaning |
|---|---|
39.9042, 116.4074 | decimal pair, lat, lon order |
116.4074E, 39.9042N | pair with suffixes — order is irrelevant, axes come from suffixes |
39°54′15″N 116°23′27″E | DMS pair (comma optional when suffixed) |
37°46′30″N / 37d46m30sN / 37:46:30N / 37 46 30 N | single DMS coordinate |
37.775N / -122.419 | single decimal (negative = S/W) |
37.775, kind: "lat" | unsuffixed single value with an explicit axis hint |
Invalid input returns valid: false with a reason — never a silent guess.
Tools
| Tool | Purpose |
|---|---|
geo_distance | haversine distance, km/m/mi/nmi, initial & final bearing, compass point |
geo_bearing | initial/final bearings + great-circle midpoint |
geo_destination | destination point from start + bearing + distance, with round-trip check |
coord_parse | parse/validate decimal & DMS coordinate strings → decimal degrees + DMS |
Configuration
plugins:
dsh-geodesy:
radiusKm: 6371.0088 # sphere radius; use 1737.4 for the Moon, 3389.5 for MarsDevelopment
pnpm install
pnpm build
pnpm test # 115 tests, anchored to independently computed closed-form values
pnpm lintLicense
MIT © TYEclipse