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2025 年 4 月 15 日前註冊使用 Earth Engine 的非商業專案,都必須
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ee.Geometry.MultiLineString.length
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
傳回幾何的線性部分長度。系統會忽略多邊形部分。多重幾何圖形的長度是其元件長度的總和。
用量 | 傳回 |
---|
MultiLineString.length(maxError, proj) | 浮點值 |
引數 | 類型 | 詳細資料 |
---|
這個:geometry | 幾何圖形 | 輸入幾何圖形。 |
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,結果會以這個投影的座標系統單位表示。否則單位為公尺。 |
範例
程式碼編輯器 (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 length method to the MultiLineString object.
var multiLineStringLength = multiLineString.length();
// Print the result to the console.
print('multiLineString.length(...) =', multiLineStringLength);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(multiLineString,
{'color': 'black'},
'Geometry [black]: multiLineString');
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 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 length method to the MultiLineString object.
multilinestring_length = multilinestring.length()
# Print the result.
display('multilinestring.length(...) =', multilinestring_length)
# 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
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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\u003eCalculates the total length of the linear parts within a geometry, excluding any polygonal areas.\u003c/p\u003e\n"],["\u003cp\u003eReturns the sum of all component lengths for multi-geometries like MultiLineString.\u003c/p\u003e\n"],["\u003cp\u003eThe length is calculated in meters by default, but can be obtained in the units of a specified projection using the \u003ccode\u003eproj\u003c/code\u003e parameter.\u003c/p\u003e\n"],["\u003cp\u003eAn optional \u003ccode\u003emaxError\u003c/code\u003e parameter controls the tolerance for reprojection errors during length calculation.\u003c/p\u003e\n"]]],[],null,["# ee.Geometry.MultiLineString.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| MultiLineString.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 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 length method to the MultiLineString object.\nvar multiLineStringLength = multiLineString.length();\n\n// Print the result to the console.\nprint('multiLineString.length(...) =', multiLineStringLength);\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');\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 length method to the MultiLineString object.\nmultilinestring_length = multilinestring.length()\n\n# Print the result.\ndisplay('multilinestring.length(...) =', multilinestring_length)\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\n```"]]