FeatureCollection en Google Earth Engine (gee)

Tabla de contenido

estructura basica

FeatureCollection.geometry ()

Genere puntos aleatorios: FeatureCollection.randomPoints ()

FeatureCollection 中 limit （） 、 sort （）

FilterBounds (), filterMetadata () en FeatureCollection

Primero (), seleccione () en FeatureCollection

FeatureCollection.union ()

FeatureCollection.merge ()

Obtener, configurar, configurarMulti en FeatureCollection

Vector a ráster: FeatureCollection.reduceToImage ()

FeatureCollection.toList ()

Comandos de estadísticas de atributos de la colección de características: Feature Collection.aggregate_array (), etc.

Feature Collection.map ()

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estructura basica

FeatureCollection.geometry ()

Genere puntos aleatorios: FeatureCollection.randomPoints ()

FeatureCollection 中 limit （） 、 sort （）

En el parámetro, verdadero significa orden ascendente, falso significa orden descendente

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");

print("fc_sichuan",fc_sichuan)
print("fc_sichuan.limit(1)",fc_sichuan.limit(1))
print("subFeature_asc",fc_sichuan.limit(3,'subFeature',true))
print("sort_asc",fc_sichuan.sort('subFeature',true).limit(3))

FilterBounds (), filterMetadata () en FeatureCollection

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");

Map.centerObject(fc_sichuan)

Map.addLayer(fc_sichuan)
Map.addLayer(fc_sichuan.filterBounds(ee.Geometry.Point([104.091,30.598])),{color:'FF0000'})
Map.addLayer(fc_sichuan.filterMetadata('name','equals','绵阳市'),{color:'FFF000'})

Primero (), seleccione () en FeatureCollection

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");
print(fc_sichuan.first())
print(fc_sichuan.limit(3).select(['name','adcode']))

FeatureCollection.union ()

union: Union. El efecto es formar una sola entidad y borrar todos los atributos.

FeatureCollection.merge ()

Fusionar: fusionar dos conjuntos de datos

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");
var chengdu=fc_sichuan.filterMetadata('name','equals','成都市')
var deyang=fc_sichuan.filterMetadata('name','equals','德阳市')

Map.centerObject(fc_sichuan)

Map.addLayer(fc_sichuan,{},"fc_sichuan")
Map.addLayer(chengdu,{color:'FF0000'},"chengdu")
Map.addLayer(deyang,{color:'FFF000'},"deyang")
Map.addLayer(chengdu.merge(deyang),{color:'00ff00'},"merge")

print(chengdu)
print(deyang)
print(chengdu.merge(deyang))

Obtener, configurar, configurarMulti en FeatureCollection

Al usar set, si el atributo no existe, agréguelo; si lo tiene, actualícelo

var fc =ee.FeatureCollection(ee.Geometry.Point([95.169, 34.513]));
      
print(fc)
print(fc.set('create','lijiang'))
print(fc.set('create','lijiang').get('create'))
print(ee.FeatureCollection(fc.set('create','lijiang')).set('create','xiaoming'))
print(fc.setMulti({"create":"lijiang","age":22}))

Vector a ráster: FeatureCollection.reduceToImage ()

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");

var sichuan_toImage=fc_sichuan.reduceToImage(['subFeature'],ee.Reducer.first())

Map.centerObject(fc_sichuan)
Map.addLayer(fc_sichuan,{},"fc_sichuan")
Map.addLayer(sichuan_toImage,{"min":1,"max":30,"palette":["ff9c07","f0ff1b","1aff0b"]},"sichuan_toImage")

print("fc_sichuan",fc_sichuan)
print("sichuan_toImage",sichuan_toImage)

FeatureCollection.toList ()

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");

print("fc_sichuan",fc_sichuan)
print(fc_sichuan.toList(5))
print(fc_sichuan.toList(5).get(0))

Comandos de estadísticas de atributos de la colección de características: Feature Collection.aggregate_array (), etc.

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");

print(fc_sichuan)
print(fc_sichuan.aggregate_array("subFeature"))
print(fc_sichuan.aggregate_stats("subFeature"))
print("aggregate_first",fc_sichuan.aggregate_first("subFeature"))
print("aggregate_max",fc_sichuan.aggregate_max("subFeature"))
print("aggregate_count",fc_sichuan.aggregate_count("subFeature"))

Los siguientes son los comandos de estadísticas de atributos relacionados con la colección de características en GEE:

Feature Collection.map ()

var fc_sichuan = ee.FeatureCollection("users/lcljv1066965/test/sichuan");

function Add_Center (feature){
  return feature.centroid()
}

print("fc_sichuan",fc_sichuan.limit(3))
print("fc_sichuan.map(Add_Center)",fc_sichuan.map(Add_Center).limit(3))

Map.centerObject(fc_sichuan)
Map.addLayer(fc_sichuan)
Map.addLayer(fc_sichuan.map(Add_Center),{color:'ff0000'})