measurement_polygonTangents
Calculate tangent points from a given location to a polygon boundary using Turf.js geospatial analysis. This tool identifies two points where lines from the point touch the polygon without crossing it.
Instructions
计算多边形上的切线点。
该函数使用 Turf.js 库的 polygonTangents 方法，计算从给定点到多边形（或多边形集合）的两个切线点。
Args: point: 点 GeoJSON 特征或几何图形 - 类型: str (JSON 字符串格式的 GeoJSON) - 格式: 必须符合 GeoJSON Point 规范 - 坐标系: WGS84 (经度在前，纬度在后) - 示例: '{"type": "Point", "coordinates": [61, 5]}'
polygon: 多边形 GeoJSON 特征或几何图形
- 类型: str (JSON 字符串格式的 GeoJSON)
- 格式: 必须符合 GeoJSON Polygon 或 MultiPolygon 规范
- 坐标系: WGS84 (经度在前，纬度在后)
- 示例: '{"type": "Polygon", "coordinates": [[[11, 0], [22, 4], [31, 0], [31, 11], [21, 15], [11, 11], [11, 0]]]}'Returns: str: JSON 字符串格式的 GeoJSON FeatureCollection - 类型: GeoJSON FeatureCollection with Point features - 格式: {"type": "FeatureCollection", "features": [{"type": "Feature", "geometry": {"type": "Point", "coordinates": [lng1, lat1]}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [lng2, lat2]}}]} - 示例: '{"type": "FeatureCollection", "features": [{"type": "Feature", "geometry": {"type": "Point", "coordinates": [15, 8]}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [25, 3]}}]}'
Raises: Exception: 当 JavaScript 执行失败、超时或输入数据格式错误时抛出异常
Example: >>> import asyncio >>> point = '{"type": "Point", "coordinates": [61, 5]}' >>> polygon = '{"type": "Polygon", "coordinates": [[[11, 0], [22, 4], [31, 0], [31, 11], [21, 15], [11, 11], [11, 0]]]}' >>> result = asyncio.run(polygonTangents(point, polygon)) >>> print(result) '{"type": "FeatureCollection", "features": [{"type": "Feature", "geometry": {"type": "Point", "coordinates": [15, 8]}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [25, 3]}}]}'
Notes: - 输入参数 point 和 polygon 必须是有效的 JSON 字符串 - 坐标顺序为 [经度, 纬度] (WGS84 坐标系) - 返回两个切线点，分别对应多边形的两个切线 - 依赖于 Turf.js 库和 Node.js 环境
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| point | Yes | ||
| polygon | Yes |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |