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ee.Geometry.LineString.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 |
---|
LineString.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 LineString object.
var lineString = ee.Geometry.LineString([[-122.09, 37.42], [-122.08, 37.43]]);
// Apply the centroid method to the LineString object.
var lineStringCentroid = lineString.centroid({'maxError': 1});
// Print the result to the console.
print('lineString.centroid(...) =', lineStringCentroid);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(lineString,
{'color': 'black'},
'Geometry [black]: lineString');
Map.addLayer(lineStringCentroid,
{'color': 'red'},
'Result [red]: lineString.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 LineString object.
linestring = ee.Geometry.LineString([[-122.09, 37.42], [-122.08, 37.43]])
# Apply the centroid method to the LineString object.
linestring_centroid = linestring.centroid(maxError=1)
# Print the result.
display('linestring.centroid(...) =', linestring_centroid)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(linestring, {'color': 'black'}, 'Geometry [black]: linestring')
m.add_layer(
linestring_centroid, {'color': 'red'}, 'Result [red]: linestring.centroid'
)
m
如未另行说明,那么本页面中的内容已根据知识共享署名 4.0 许可获得了许可,并且代码示例已根据 Apache 2.0 许可获得了许可。有关详情,请参阅 Google 开发者网站政策。Java 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC):2025-07-26。
[null,null,["最后更新时间 (UTC):2025-07-26。"],[[["\u003cp\u003eReturns a point representing the center of the highest-dimension components of a geometry, ignoring lower-dimensional ones.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003ecentroid()\u003c/code\u003e method can be applied to geometries and takes optional \u003ccode\u003emaxError\u003c/code\u003e and \u003ccode\u003eproj\u003c/code\u003e arguments for customization.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003emaxError\u003c/code\u003e controls the tolerance for reprojection errors, while \u003ccode\u003eproj\u003c/code\u003e specifies the output projection (defaults to EPSG:4326).\u003c/p\u003e\n"],["\u003cp\u003eIt is demonstrated with examples using both JavaScript and Python within the Google Earth Engine environment.\u003c/p\u003e\n"]]],["The `centroid` method calculates the center point of a geometry's highest-dimensional components, disregarding lower-dimensional ones. It accepts optional `maxError` and `proj` arguments to control error tolerance and output projection. For a `LineString` object, the method returns a `Geometry` object representing the centroid. Example code shows defining a `LineString`, applying `centroid`, and visualizing both on a map. The function is shown in Javascript and Python.\n"],null,["# ee.Geometry.LineString.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| LineString.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 LineString object.\nvar lineString = ee.Geometry.LineString([[-122.09, 37.42], [-122.08, 37.43]]);\n\n// Apply the centroid method to the LineString object.\nvar lineStringCentroid = lineString.centroid({'maxError': 1});\n\n// Print the result to the console.\nprint('lineString.centroid(...) =', lineStringCentroid);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(lineString,\n {'color': 'black'},\n 'Geometry [black]: lineString');\nMap.addLayer(lineStringCentroid,\n {'color': 'red'},\n 'Result [red]: lineString.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 LineString object.\nlinestring = ee.Geometry.LineString([[-122.09, 37.42], [-122.08, 37.43]])\n\n# Apply the centroid method to the LineString object.\nlinestring_centroid = linestring.centroid(maxError=1)\n\n# Print the result.\ndisplay('linestring.centroid(...) =', linestring_centroid)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(linestring, {'color': 'black'}, 'Geometry [black]: linestring')\nm.add_layer(\n linestring_centroid, {'color': 'red'}, 'Result [red]: linestring.centroid'\n)\nm\n```"]]