ee.FeatureCollection.makeArray

  • makeArray() combines specified numeric properties of features within a FeatureCollection into a new 1-D array property.

  • Features lacking any of the specified properties, or containing non-numeric values in those properties, are excluded from the output.

  • The resulting FeatureCollection contains the original features with an added array property holding the combined values.

  • The array property is named using the 'name' argument, defaulting to "array" if not provided.

 Add a 1-D Array to each feature in a collection by combining a list of properties for each feature into a 1-D Array. All of the properties must be numeric values. If a feature doesn't contain all of the named properties, or any of them aren't numeric, the feature will be dropped from the resulting collection.

UsageReturns
FeatureCollection.makeArray(properties, name)FeatureCollection
ArgumentTypeDetails
this: collectionFeatureCollectionThe input collection from which properties will be selected.
propertiesListThe properties to select.
nameString, default: "array"The name of the new array property.

Examples

Code Editor (JavaScript)

// FeatureCollection of power plants in Belgium.
var fc = ee.FeatureCollection('WRI/GPPD/power_plants')
            .filter('country_lg == "Belgium"');

// A list of feature properties to combine into an array
// (power generation by year).
var properties = ['gwh_2013', 'gwh_2014', 'gwh_2015', 'gwh_2016'];

// Add array of power-generation-by-year property to features.
fc = fc.makeArray(properties, 'gwh_by_year');

print('FeatureCollection with array of selected properties added', fc);
print('See example of new "gwh_by_year" property', fc.first().toDictionary());

Python setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

import ee
import geemap.core as geemap

Colab (Python)

from pprint import pprint

# FeatureCollection of power plants in Belgium.
fc = ee.FeatureCollection('WRI/GPPD/power_plants').filter(
    'country_lg == "Belgium"')

# A list of feature properties to combine into an array
# (power generation by year).
properties = ['gwh_2013', 'gwh_2014', 'gwh_2015', 'gwh_2016']

# Add array of power-generation-by-year property to features.
fc = fc.makeArray(properties, 'gwh_by_year')

print('FeatureCollection with array of selected properties added:',
      fc.getInfo())
print('See example of new "gwh_by_year" property:')
pprint(fc.first().toDictionary().getInfo())