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ee.Geometry.LinearRing.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 |
---|
LinearRing.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 LinearRing object.
var linearRing = ee.Geometry.LinearRing(
[[-122.091, 37.420],
[-122.085, 37.422],
[-122.080, 37.430]]);
// Apply the centroid method to the LinearRing object.
var linearRingCentroid = linearRing.centroid({'maxError': 1});
// Print the result to the console.
print('linearRing.centroid(...) =', linearRingCentroid);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(linearRing,
{'color': 'black'},
'Geometry [black]: linearRing');
Map.addLayer(linearRingCentroid,
{'color': 'red'},
'Result [red]: linearRing.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 LinearRing object.
linearring = ee.Geometry.LinearRing(
[[-122.091, 37.420], [-122.085, 37.422], [-122.080, 37.430]]
)
# Apply the centroid method to the LinearRing object.
linearring_centroid = linearring.centroid(maxError=1)
# Print the result.
display('linearring.centroid(...) =', linearring_centroid)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(linearring, {'color': 'black'}, 'Geometry [black]: linearring')
m.add_layer(
linearring_centroid, {'color': 'red'}, 'Result [red]: linearring.centroid'
)
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\u003e\u003ccode\u003ecentroid()\u003c/code\u003e returns a point at the center of the highest-dimension components of a geometry, ignoring lower dimensions.\u003c/p\u003e\n"],["\u003cp\u003eIt is applicable to \u003ccode\u003eLinearRing\u003c/code\u003e geometries and accepts optional \u003ccode\u003emaxError\u003c/code\u003e and \u003ccode\u003eproj\u003c/code\u003e parameters.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003emaxError\u003c/code\u003e controls the reprojection error tolerance, while \u003ccode\u003eproj\u003c/code\u003e specifies the output projection (defaults to EPSG:4326).\u003c/p\u003e\n"],["\u003cp\u003eThe function effectively calculates the geometric center of the input geometry.\u003c/p\u003e\n"]]],["The `centroid()` method calculates the center point of a geometry's highest-dimension components, disregarding lower-dimensional parts. It accepts `maxError` to control reprojection tolerance and `proj` to specify the output projection, defaulting to EPSG:4326. It applies to geometry such as a `LinearRing` and outputs the center point as a `Geometry` object. Examples show its use in Javascript and Python, creating a centroid and visually displaying it with its source geometry.\n"],null,["# ee.Geometry.LinearRing.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| LinearRing.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 LinearRing object.\nvar linearRing = ee.Geometry.LinearRing(\n [[-122.091, 37.420],\n [-122.085, 37.422],\n [-122.080, 37.430]]);\n\n// Apply the centroid method to the LinearRing object.\nvar linearRingCentroid = linearRing.centroid({'maxError': 1});\n\n// Print the result to the console.\nprint('linearRing.centroid(...) =', linearRingCentroid);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(linearRing,\n {'color': 'black'},\n 'Geometry [black]: linearRing');\nMap.addLayer(linearRingCentroid,\n {'color': 'red'},\n 'Result [red]: linearRing.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 LinearRing object.\nlinearring = ee.Geometry.LinearRing(\n [[-122.091, 37.420], [-122.085, 37.422], [-122.080, 37.430]]\n)\n\n# Apply the centroid method to the LinearRing object.\nlinearring_centroid = linearring.centroid(maxError=1)\n\n# Print the result.\ndisplay('linearring.centroid(...) =', linearring_centroid)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(linearring, {'color': 'black'}, 'Geometry [black]: linearring')\nm.add_layer(\n linearring_centroid, {'color': 'red'}, 'Result [red]: linearring.centroid'\n)\nm\n```"]]