公告:凡是在
2025 年 4 月 15 日前註冊使用 Earth Engine 的非商業專案,都必須
驗證非商業用途資格,才能繼續存取。如未在 2025 年 9 月 26 日前完成驗證,存取權可能會暫停。
ee.FeatureCollection.flatten
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
將集合的集合扁平化。
用量 | 傳回 |
---|
FeatureCollection.flatten() | FeatureCollection |
引數 | 類型 | 詳細資料 |
---|
這個:collection | FeatureCollection | 集合的輸入集合。 |
範例
程式碼編輯器 (JavaScript)
// Counties in New Mexico, USA.
var counties = ee.FeatureCollection('TIGER/2018/Counties')
.filter('STATEFP == "35"');
// Monthly climate and climatic water balance surfaces for January 2020.
var climate = ee.ImageCollection('IDAHO_EPSCOR/TERRACLIMATE')
.filterDate('2020-01', '2020-02');
// Calculate mean climate variables for each county per climate surface
// time step. The result is a FeatureCollection of FeatureCollections.
var countiesClimate = climate.map(function(image) {
return image.reduceRegions({
collection: counties,
reducer: ee.Reducer.mean(),
scale: 5000,
crs: 'EPSG:4326'
});
});
// Note that a printed FeatureCollection of FeatureCollections is not
// recursively expanded, you cannot view metadata of the features within the
// nested collections until you isolate a single collection or flatten the
// collections.
print('FeatureCollection of FeatureCollections', countiesClimate);
print('Flattened FeatureCollection of FeatureCollections',
countiesClimate.flatten());
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)
# Counties in New Mexico, USA.
counties = ee.FeatureCollection('TIGER/2018/Counties').filter('STATEFP == "35"')
# Monthly climate and climatic water balance surfaces for January 2020.
climate = ee.ImageCollection('IDAHO_EPSCOR/TERRACLIMATE').filterDate(
'2020-01', '2020-02')
# Calculate mean climate variables for each county per climate surface
# time step. The result is a FeatureCollection of FeatureCollections.
def reduce_mean(image):
return image.reduceRegions(**{
'collection': counties,
'reducer': ee.Reducer.mean(),
'scale': 5000,
'crs': 'EPSG:4326'
})
counties_climate = climate.map(reduce_mean)
# Note that a printed FeatureCollection of FeatureCollections is not
# recursively expanded, you cannot view metadata of the features within the
# nested collections until you isolate a single collection or flatten the
# collections.
print('FeatureCollection of FeatureCollections:', counties_climate.getInfo())
print('Flattened FeatureCollection of FeatureCollections:',
counties_climate.flatten().getInfo())
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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)。"],[],["The `flatten()` method transforms a nested `FeatureCollection` of `FeatureCollections` into a single, flat `FeatureCollection`. It takes a `FeatureCollection` as input and returns a flattened `FeatureCollection`. This allows for the metadata of features within the nested collections to be viewed, which is not possible with unflattened collections. An example demonstrates calculating mean climate variables for counties per climate surface timestep and then flattening the resulting nested collection.\n"]]