ee.FeatureCollection.cluster

Regroupe chaque caractéristique d'une collection en clusters, en ajoutant à chaque caractéristique une colonne contenant le numéro du cluster auquel elle a été attribuée.

Utilisation	Renvoie
FeatureCollection.cluster(clusterer, outputName)	FeatureCollection

Argument	Type	Détails
ceci : features	FeatureCollection	Collection d'entités à regrouper en clusters. Chaque caractéristique doit contenir toutes les propriétés du schéma du cluster.
clusterer	Clusterer	Cluster à utiliser.
outputName	Chaîne, valeur par défaut : "cluster"	Nom de la propriété de sortie à ajouter.

Exemples

Éditeur de code (JavaScript)

// Import a Sentinel-2 surface reflectance image.
var image = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG');

// Get the image geometry to define the geographical bounds of a point sample.
var imageBounds = image.geometry();

// Sample the image at a set of random points; a feature collection is returned.
var pointSampleFc = image.sample(
    {region: imageBounds, scale: 20, numPixels: 1000, geometries: true});

// Instantiate a k-means clusterer and train it.
var clusterer = ee.Clusterer.wekaKMeans(5).train(pointSampleFc);

// Cluster the input using the trained clusterer; optionally specify the name
// of the output cluster ID property.
var clusteredFc = pointSampleFc.cluster(clusterer, 'spectral_cluster');

print('Note added "spectral_cluster" property for an example feature',
      clusteredFc.first().toDictionary());

// Visualize the clusters by applying a unique color to each cluster ID.
var palette = ee.List(['8dd3c7', 'ffffb3', 'bebada', 'fb8072', '80b1d3']);
var clusterVis = clusteredFc.map(function(feature) {
  return feature.set('style', {
    color: palette.get(feature.get('spectral_cluster')),
  });
}).style({styleProperty: 'style'});

// Display the points colored by cluster ID with the S2 image.
Map.setCenter(-122.35, 37.47, 9);
Map.addLayer(image, {bands: ['B4', 'B3', 'B2'], min: 0, max: 1500}, 'S2 image');
Map.addLayer(clusterVis, null, 'Clusters');

Configuration de Python

Consultez la page Environnement Python pour en savoir plus sur l'API Python et sur l'utilisation de geemap pour le développement interactif.

import ee
import geemap.core as geemap

Colab (Python)

# Import a Sentinel-2 surface reflectance image.
image = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG')

# Get the image geometry to define the geographical bounds of a point sample.
image_bounds = image.geometry()

# Sample the image at a set of random points a feature collection is returned.
point_sample_fc = image.sample(
    region=image_bounds, scale=20, numPixels=1000, geometries=True
)

# Instantiate a k-means clusterer and train it.
clusterer = ee.Clusterer.wekaKMeans(5).train(point_sample_fc)

# Cluster the input using the trained clusterer optionally specify the name
# of the output cluster ID property.
clustered_fc = point_sample_fc.cluster(clusterer, 'spectral_cluster')

display(
    'Note added "spectral_cluster" property for an example feature',
    clustered_fc.first().toDictionary(),
)

# Visualize the clusters by applying a unique color to each cluster ID.
palette = ee.List(['8dd3c7', 'ffffb3', 'bebada', 'fb8072', '80b1d3'])
cluster_vis = clustered_fc.map(
    lambda feature: feature.set(
        'style', {'color': palette.get(feature.get('spectral_cluster'))}
    )
).style(styleProperty='style')

# Display the points colored by cluster ID with the S2 image.
m = geemap.Map()
m.set_center(-122.35, 37.47, 9)
m.add_layer(
    image, {'bands': ['B4', 'B3', 'B2'], 'min': 0, 'max': 1500}, 'S2 image'
)
m.add_layer(cluster_vis, None, 'Clusters')
m