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ee.Geometry.MultiLineString.centroid
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
返回几何图形的最高维度组件中心的点。系统会忽略低维度的组成部分,因此包含两个多边形、三条线和一个点的几何图形的形心与仅包含这两个多边形的几何图形的形心相同。
用法 | 返回 |
---|
MultiLineString.centroid(maxError, proj) | 几何图形 |
参数 | 类型 | 详细信息 |
---|
此:geometry | 几何图形 | 计算相应几何图形的形心。 |
maxError | ErrorMargin,默认值:null | 执行任何必要的重新投影时可容忍的最大误差量。 |
proj | 投影,默认值:null | 如果指定了此参数,结果将采用此投影。否则,它将采用 EPSG:4326。 |
示例
代码编辑器 (JavaScript)
// Define a MultiLineString object.
var multiLineString = ee.Geometry.MultiLineString(
[[[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],
[[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]]]);
// Apply the centroid method to the MultiLineString object.
var multiLineStringCentroid = multiLineString.centroid({'maxError': 1});
// Print the result to the console.
print('multiLineString.centroid(...) =', multiLineStringCentroid);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(multiLineString,
{'color': 'black'},
'Geometry [black]: multiLineString');
Map.addLayer(multiLineStringCentroid,
{'color': 'red'},
'Result [red]: multiLineString.centroid');
Python 设置
如需了解 Python API 和如何使用 geemap
进行交互式开发,请参阅
Python 环境页面。
import ee
import geemap.core as geemap
Colab (Python)
# Define a MultiLineString object.
multilinestring = ee.Geometry.MultiLineString([
[[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],
[[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]],
])
# Apply the centroid method to the MultiLineString object.
multilinestring_centroid = multilinestring.centroid(maxError=1)
# Print the result.
display('multilinestring.centroid(...) =', multilinestring_centroid)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(
multilinestring, {'color': 'black'}, 'Geometry [black]: multilinestring'
)
m.add_layer(
multilinestring_centroid,
{'color': 'red'},
'Result [red]: multilinestring.centroid',
)
m
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最后更新时间 (UTC):2025-07-26。
[null,null,["最后更新时间 (UTC):2025-07-26。"],[[["\u003cp\u003eReturns the center point of the highest-dimension components of a geometry, ignoring lower dimensions.\u003c/p\u003e\n"],["\u003cp\u003eAccepts an optional \u003ccode\u003emaxError\u003c/code\u003e for reprojection and an optional \u003ccode\u003eproj\u003c/code\u003e to specify the output projection (defaults to EPSG:4326).\u003c/p\u003e\n"],["\u003cp\u003eCan be applied to MultiLineString geometries to calculate their centroid.\u003c/p\u003e\n"]]],["The `centroid()` method calculates the center point of a geometry's highest-dimensional components, disregarding lower-dimensional ones. It accepts `maxError` to control reprojection tolerance and `proj` to specify the output projection, defaulting to EPSG:4326. When applied to a `MultiLineString`, it returns a `Geometry` representing the center. The provided examples show how to apply the `centroid()` method in Javascript and Python to get the centroid of a MultiLineString and displaying it on a map.\n"],null,["# ee.Geometry.MultiLineString.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| MultiLineString.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 MultiLineString object.\nvar multiLineString = ee.Geometry.MultiLineString(\n [[[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],\n [[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]]]);\n\n// Apply the centroid method to the MultiLineString object.\nvar multiLineStringCentroid = multiLineString.centroid({'maxError': 1});\n\n// Print the result to the console.\nprint('multiLineString.centroid(...) =', multiLineStringCentroid);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(multiLineString,\n {'color': 'black'},\n 'Geometry [black]: multiLineString');\nMap.addLayer(multiLineStringCentroid,\n {'color': 'red'},\n 'Result [red]: multiLineString.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 MultiLineString object.\nmultilinestring = ee.Geometry.MultiLineString([\n [[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],\n [[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]],\n])\n\n# Apply the centroid method to the MultiLineString object.\nmultilinestring_centroid = multilinestring.centroid(maxError=1)\n\n# Print the result.\ndisplay('multilinestring.centroid(...) =', multilinestring_centroid)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(\n multilinestring, {'color': 'black'}, 'Geometry [black]: multilinestring'\n)\nm.add_layer(\n multilinestring_centroid,\n {'color': 'red'},\n 'Result [red]: multilinestring.centroid',\n)\nm\n```"]]