公告:凡是在
2025 年 4 月 15 日前註冊使用 Earth Engine 的非商業專案,都必須
驗證非商業用途資格,才能繼續存取 Earth Engine。
ee.Geometry.MultiPolygon.centroid
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
傳回幾何體最高維度元件中心的點。系統會忽略低維度元件,因此含有兩個多邊形、三條線和一個點的幾何圖形質心,等同於只含有兩個多邊形的幾何圖形質心。
用量 | 傳回 |
---|
MultiPolygon.centroid(maxError, proj) | 幾何圖形 |
引數 | 類型 | 詳細資料 |
---|
這個:geometry | 幾何圖形 | 計算這個幾何體的重心。 |
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 | 如果指定,結果會以這個投影方式呈現。否則會採用 EPSG:4326。 |
範例
程式碼編輯器 (JavaScript)
// Define a MultiPolygon object.
var multiPolygon = ee.Geometry.MultiPolygon(
[[[[-122.092, 37.424],
[-122.086, 37.418],
[-122.079, 37.425],
[-122.085, 37.423]]],
[[[-122.081, 37.417],
[-122.086, 37.421],
[-122.089, 37.416]]]]);
// Apply the centroid method to the MultiPolygon object.
var multiPolygonCentroid = multiPolygon.centroid({'maxError': 1});
// Print the result to the console.
print('multiPolygon.centroid(...) =', multiPolygonCentroid);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(multiPolygon,
{'color': 'black'},
'Geometry [black]: multiPolygon');
Map.addLayer(multiPolygonCentroid,
{'color': 'red'},
'Result [red]: multiPolygon.centroid');
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 MultiPolygon object.
multipolygon = ee.Geometry.MultiPolygon([
[[
[-122.092, 37.424],
[-122.086, 37.418],
[-122.079, 37.425],
[-122.085, 37.423],
]],
[[[-122.081, 37.417], [-122.086, 37.421], [-122.089, 37.416]]],
])
# Apply the centroid method to the MultiPolygon object.
multipolygon_centroid = multipolygon.centroid(maxError=1)
# Print the result.
display('multipolygon.centroid(...) =', multipolygon_centroid)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(
multipolygon, {'color': 'black'}, 'Geometry [black]: multipolygon'
)
m.add_layer(
multipolygon_centroid,
{'color': 'red'},
'Result [red]: multipolygon.centroid',
)
m
除非另有註明,否則本頁面中的內容是採用創用 CC 姓名標示 4.0 授權,程式碼範例則為阿帕契 2.0 授權。詳情請參閱《Google Developers 網站政策》。Java 是 Oracle 和/或其關聯企業的註冊商標。
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 a point representing the center of the highest-dimension components within a geometry, ignoring lower dimensions.\u003c/p\u003e\n"],["\u003cp\u003eAccepts optional \u003ccode\u003emaxError\u003c/code\u003e and \u003ccode\u003eproj\u003c/code\u003e arguments for error tolerance during reprojection and specifying the output projection, respectively.\u003c/p\u003e\n"],["\u003cp\u003eThe default projection for the returned centroid is EPSG:4326 if \u003ccode\u003eproj\u003c/code\u003e is not specified.\u003c/p\u003e\n"],["\u003cp\u003eCan be applied to MultiPolygon objects to calculate their center point.\u003c/p\u003e\n"]]],["The `centroid()` method calculates the center point of a geometry's highest-dimensional components, ignoring lower-dimensional ones. It accepts `maxError` for reprojection tolerance and `proj` for specifying the output projection. By default it returns a Geometry in EPSG:4326. Example provided how to generate the centroid of a `MultiPolygon` using both JavaScript and Python code. The example code displays the input polygon and the resulting centroid on a map.\n"],null,["# ee.Geometry.MultiPolygon.centroid\n\nReturns a point at the center of the highest-dimension components of the geometry. Lower-dimensional components are ignored, so the centroid of a geometry containing two polygons, three lines and a point is equivalent to the centroid of a geometry containing just the two polygons.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|--------------------------------------------------|----------|\n| MultiPolygon.centroid`(`*maxError* `, `*proj*`)` | Geometry |\n\n| Argument | Type | Details |\n|------------------|----------------------------|-----------------------------------------------------------------------------------------|\n| this: `geometry` | Geometry | Calculates the centroid of this geometry. |\n| `maxError` | ErrorMargin, default: null | The maximum amount of error tolerated when performing any necessary reprojection. |\n| `proj` | Projection, default: null | If specified, the result will be in this projection. Otherwise it will be in EPSG:4326. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Define a MultiPolygon object.\nvar multiPolygon = ee.Geometry.MultiPolygon(\n [[[[-122.092, 37.424],\n [-122.086, 37.418],\n [-122.079, 37.425],\n [-122.085, 37.423]]],\n [[[-122.081, 37.417],\n [-122.086, 37.421],\n [-122.089, 37.416]]]]);\n\n// Apply the centroid method to the MultiPolygon object.\nvar multiPolygonCentroid = multiPolygon.centroid({'maxError': 1});\n\n// Print the result to the console.\nprint('multiPolygon.centroid(...) =', multiPolygonCentroid);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(multiPolygon,\n {'color': 'black'},\n 'Geometry [black]: multiPolygon');\nMap.addLayer(multiPolygonCentroid,\n {'color': 'red'},\n 'Result [red]: multiPolygon.centroid');\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 MultiPolygon object.\nmultipolygon = ee.Geometry.MultiPolygon([\n [[\n [-122.092, 37.424],\n [-122.086, 37.418],\n [-122.079, 37.425],\n [-122.085, 37.423],\n ]],\n [[[-122.081, 37.417], [-122.086, 37.421], [-122.089, 37.416]]],\n])\n\n# Apply the centroid method to the MultiPolygon object.\nmultipolygon_centroid = multipolygon.centroid(maxError=1)\n\n# Print the result.\ndisplay('multipolygon.centroid(...) =', multipolygon_centroid)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(\n multipolygon, {'color': 'black'}, 'Geometry [black]: multipolygon'\n)\nm.add_layer(\n multipolygon_centroid,\n {'color': 'red'},\n 'Result [red]: multipolygon.centroid',\n)\nm\n```"]]