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ee.Geometry.BBox.length
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。
返回几何图形的线性部分的长度。多边形部分会被忽略。多几何图形的长度是其组成部分的长度之和。
| 用法 | 返回 |
|---|
BBox.length(maxError, proj) | 浮点数 |
| 参数 | 类型 | 详细信息 |
|---|
此：geometry | 几何图形 | 输入几何图形。 |
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，结果将采用相应投影的坐标系的单位。否则将以米为单位。 |
示例
代码编辑器 (JavaScript)
// Define a BBox object.
var bBox = ee.Geometry.BBox(-122.09, 37.42, -122.08, 37.43);
// Apply the length method to the BBox object.
var bBoxLength = bBox.length();
// Print the result to the console.
print('bBox.length(...) =', bBoxLength);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(bBox,
{'color': 'black'},
'Geometry [black]: bBox');
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 BBox object.
bbox = ee.Geometry.BBox(-122.09, 37.42, -122.08, 37.43)
# Apply the length method to the BBox object.
bbox_length = bbox.length()
# Print the result.
display('bbox.length(...) =', bbox_length)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(bbox, {'color': 'black'}, 'Geometry [black]: bbox')
m
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最后更新时间 (UTC)：2025-07-29。
[null,null,["最后更新时间 (UTC)：2025-07-29。"],[[["\u003cp\u003eThis function calculates the total length of the linear segments within a geometry, excluding any polygonal areas.\u003c/p\u003e\n"],["\u003cp\u003eMulti-geometries have their lengths determined by summing the lengths of their individual components.\u003c/p\u003e\n"],["\u003cp\u003eThe function can optionally be executed with a specified projection, affecting the units of the output.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003elength()\u003c/code\u003e function ignores polygonal segments within geometries and focuses only on linear features.\u003c/p\u003e\n"]]],["The `length()` method calculates the length of the linear components within a geometry, excluding polygonal parts. Multi-geometry lengths are the sum of their components' lengths. It accepts optional `maxError` and `proj` arguments to define error tolerance and projection units, respectively. The default unit is meters. Examples demonstrate applying `length()` to a BBox in both JavaScript and Python, showcasing how to print and display the resulting length alongside the geometry.\n"],null,["# ee.Geometry.BBox.length\n\nReturns the length of the linear parts of the geometry. Polygonal parts are ignored. The length of multi geometries is the sum of the lengths of their components.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|----------------------------------------|---------|\n| BBox.length`(`*maxError* `, `*proj*`)` | Float |\n\n| Argument | Type | Details |\n|------------------|----------------------------|----------------------------------------------------------------------------------------------------------------------------|\n| this: `geometry` | Geometry | The input 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 the units of the coordinate system of this projection. Otherwise it will be in meters. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Define a BBox object.\nvar bBox = ee.Geometry.BBox(-122.09, 37.42, -122.08, 37.43);\n\n// Apply the length method to the BBox object.\nvar bBoxLength = bBox.length();\n\n// Print the result to the console.\nprint('bBox.length(...) =', bBoxLength);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(bBox,\n {'color': 'black'},\n 'Geometry [black]: bBox');\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 BBox object.\nbbox = ee.Geometry.BBox(-122.09, 37.42, -122.08, 37.43)\n\n# Apply the length method to the BBox object.\nbbox_length = bbox.length()\n\n# Print the result.\ndisplay('bbox.length(...) =', bbox_length)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(bbox, {'color': 'black'}, 'Geometry [black]: bbox')\nm\n```"]]
