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ee.Geometry.Polygon.convexHull
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
傳回指定幾何的凸包。單一點的凸包是該點本身,共線點的凸包是線,其他所有點的凸包都是多邊形。請注意,如果退化多邊形的所有頂點都位於同一條線上,就會產生線段。
用量 | 傳回 |
---|
Polygon.convexHull(maxError, proj) | 幾何圖形 |
引數 | 類型 | 詳細資料 |
---|
這個:geometry | 幾何圖形 | 計算這個幾何體的凸包。 |
maxError | ErrorMargin,預設值:null | 執行任何必要重投影時可容許的最大誤差量。 |
proj | 投影,預設值:null | 執行作業的投影。如未指定,系統會以球面座標系統執行作業,而球面上的線性距離會以公尺為單位。 |
範例
程式碼編輯器 (JavaScript)
// Define a Polygon object.
var polygon = ee.Geometry.Polygon(
[[[-122.092, 37.424],
[-122.086, 37.418],
[-122.079, 37.425],
[-122.085, 37.423]]]);
// Apply the convexHull method to the Polygon object.
var polygonConvexHull = polygon.convexHull({'maxError': 1});
// Print the result to the console.
print('polygon.convexHull(...) =', polygonConvexHull);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(polygon,
{'color': 'black'},
'Geometry [black]: polygon');
Map.addLayer(polygonConvexHull,
{'color': 'red'},
'Result [red]: polygon.convexHull');
Python 設定
請參閱
Python 環境頁面,瞭解 Python API 和如何使用 geemap
進行互動式開發。
import ee
import geemap.core as geemap
Colab (Python)
# Define a Polygon object.
polygon = ee.Geometry.Polygon([[
[-122.092, 37.424],
[-122.086, 37.418],
[-122.079, 37.425],
[-122.085, 37.423],
]])
# Apply the convexHull method to the Polygon object.
polygon_convex_hull = polygon.convexHull(maxError=1)
# Print the result.
display('polygon.convexHull(...) =', polygon_convex_hull)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(polygon, {'color': 'black'}, 'Geometry [black]: polygon')
m.add_layer(
polygon_convex_hull, {'color': 'red'}, 'Result [red]: polygon.convexHull'
)
m
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上次更新時間:2025-07-26 (世界標準時間)。
[null,null,["上次更新時間:2025-07-26 (世界標準時間)。"],[[["\u003cp\u003eReturns the smallest convex Polygon that encloses the given geometry.\u003c/p\u003e\n"],["\u003cp\u003eAccepts an optional \u003ccode\u003emaxError\u003c/code\u003e for reprojection and an optional \u003ccode\u003eproj\u003c/code\u003e for the projection to use.\u003c/p\u003e\n"],["\u003cp\u003eThe convex hull of a point is the point itself, collinear points result in a line, and other geometries result in a Polygon.\u003c/p\u003e\n"],["\u003cp\u003eMay return a degenerate polygon (line segment) if all vertices lie on the same line.\u003c/p\u003e\n"]]],[],null,["# ee.Geometry.Polygon.convexHull\n\nReturns the convex hull of the given geometry. The convex hull of a single point is the point itself, the convex hull of collinear points is a line, and the convex hull of everything else is a polygon. Note that a degenerate polygon with all vertices on the same line will result in a line segment.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-----------------------------------------------|----------|\n| Polygon.convexHull`(`*maxError* `, `*proj*`)` | Geometry |\n\n| Argument | Type | Details |\n|------------------|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| this: `geometry` | Geometry | Calculates the convex hull of this geometry. |\n| `maxError` | ErrorMargin, default: null | The maximum amount of error tolerated when performing any necessary reprojection. |\n| `proj` | Projection, default: null | The projection in which to perform the operation. If not specified, the operation will be performed in a spherical coordinate system, and linear distances will be in meters on the sphere. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Define a Polygon object.\nvar polygon = ee.Geometry.Polygon(\n [[[-122.092, 37.424],\n [-122.086, 37.418],\n [-122.079, 37.425],\n [-122.085, 37.423]]]);\n\n// Apply the convexHull method to the Polygon object.\nvar polygonConvexHull = polygon.convexHull({'maxError': 1});\n\n// Print the result to the console.\nprint('polygon.convexHull(...) =', polygonConvexHull);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(polygon,\n {'color': 'black'},\n 'Geometry [black]: polygon');\nMap.addLayer(polygonConvexHull,\n {'color': 'red'},\n 'Result [red]: polygon.convexHull');\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# Define a Polygon object.\npolygon = ee.Geometry.Polygon([[\n [-122.092, 37.424],\n [-122.086, 37.418],\n [-122.079, 37.425],\n [-122.085, 37.423],\n]])\n\n# Apply the convexHull method to the Polygon object.\npolygon_convex_hull = polygon.convexHull(maxError=1)\n\n# Print the result.\ndisplay('polygon.convexHull(...) =', polygon_convex_hull)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(polygon, {'color': 'black'}, 'Geometry [black]: polygon')\nm.add_layer(\n polygon_convex_hull, {'color': 'red'}, 'Result [red]: polygon.convexHull'\n)\nm\n```"]]