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ee.FeatureCollection.limit
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。
将集合限制为指定数量的元素,可以选择先按指定属性对这些元素进行排序。
返回受限集合。
用法 | 返回 |
---|
FeatureCollection.limit(max, property, ascending) | 集合 |
参数 | 类型 | 详细信息 |
---|
此:collection | 集合 | Collection 实例。 |
max | 数字 | 要将集合限制为的数字。 |
property | 字符串,可选 | 要排序的属性(如果需要排序)。 |
ascending | 布尔值,可选 | 是按升序还是降序排序。默认值为 true(升序)。 |
示例
代码编辑器 (JavaScript)
// FeatureCollection of global power plants.
var fc = ee.FeatureCollection('WRI/GPPD/power_plants');
print('First 5 features (power plants)', fc.limit(5));
print('Smallest 5 power plants by capacity in ascending order',
fc.limit({max: 5, property: 'capacitymw'}));
print('Largest 5 power plants by capacity in descending order',
fc.limit({max: 5, property: 'capacitymw', ascending: false}));
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)
# FeatureCollection of global power plants.
fc = ee.FeatureCollection('WRI/GPPD/power_plants')
print('First 5 features (power plants):', fc.limit(5).getInfo())
print('Smallest 5 power plants by capacity in ascending order:',
fc.limit(**{'maximum': 5, 'opt_property': 'capacitymw'}).getInfo())
print('Largest 5 power plants by capacity in descending order:',
fc.limit(**{'maximum': 5, 'opt_property': 'capacitymw',
'opt_ascending': False}).getInfo())
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\u003e\u003ccode\u003elimit()\u003c/code\u003e reduces a FeatureCollection to a specified number of elements.\u003c/p\u003e\n"],["\u003cp\u003eOptionally, the collection can be sorted by a property before limiting.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003emax\u003c/code\u003e sets the maximum number of elements to retain in the limited collection.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eproperty\u003c/code\u003e and \u003ccode\u003eascending\u003c/code\u003e parameters allow for sorting before limiting.\u003c/p\u003e\n"]]],[],null,["# ee.FeatureCollection.limit\n\n\u003cbr /\u003e\n\nLimit a collection to the specified number of elements, optionally sorting them by a specified property first.\n\n\u003cbr /\u003e\n\nReturns the limited collection.\n\n| Usage | Returns |\n|--------------------------------------------------------------|------------|\n| FeatureCollection.limit`(max, `*property* `, `*ascending*`)` | Collection |\n\n| Argument | Type | Details |\n|--------------------|-------------------|------------------------------------------------------------------------------------|\n| this: `collection` | Collection | The Collection instance. |\n| `max` | Number | The number to limit the collection to. |\n| `property` | String, optional | The property to sort by, if sorting. |\n| `ascending` | Boolean, optional | Whether to sort in ascending or descending order. The default is true (ascending). |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// FeatureCollection of global power plants.\nvar fc = ee.FeatureCollection('WRI/GPPD/power_plants');\n\nprint('First 5 features (power plants)', fc.limit(5));\n\nprint('Smallest 5 power plants by capacity in ascending order',\n fc.limit({max: 5, property: 'capacitymw'}));\n\nprint('Largest 5 power plants by capacity in descending order',\n fc.limit({max: 5, property: 'capacitymw', ascending: false}));\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# FeatureCollection of global power plants.\nfc = ee.FeatureCollection('WRI/GPPD/power_plants')\n\nprint('First 5 features (power plants):', fc.limit(5).getInfo())\n\nprint('Smallest 5 power plants by capacity in ascending order:',\n fc.limit(**{'maximum': 5, 'opt_property': 'capacitymw'}).getInfo())\n\nprint('Largest 5 power plants by capacity in descending order:',\n fc.limit(**{'maximum': 5, 'opt_property': 'capacitymw',\n 'opt_ascending': False}).getInfo())\n```"]]