ee.FeatureCollection.randomColumn

Adds a column of deterministic pseudorandom numbers to a collection. The outputs are double-precision floating point numbers. When using the 'uniform' distribution (default), outputs are in the range of [0, 1). Using the 'normal' distribution, outputs have μ=0, 𝛔=1, but have no explicit limits.
UsageReturns
FeatureCollection.randomColumn(columnName, seed, distribution)FeatureCollection
ArgumentTypeDetails
this: collectionFeatureCollectionThe input collection to which to add a random column.
columnNameString, default: "random"The name of the column to add.
seedLong, default: 0A seed used when generating the random numbers.
distributionString, default: "uniform"The distribution type of random numbers to produce; one of 'uniform' or 'normal'.

Examples

Code Editor (JavaScript)

// FeatureCollection of power plants in Belgium.
var fc = ee.FeatureCollection('WRI/GPPD/power_plants')
            .filter('country_lg == "Belgium"');
print('N features in collection', fc.size());

// Add a uniform distribution random value column to the FeatureCollection.
fc = fc.randomColumn();

// Randomly split the collection into two sets, 30% and 70% of the total.
var randomSample30 = fc.filter('random < 0.3');
print('N features in 30% sample', randomSample30.size());

var randomSample70 = fc.filter('random >= 0.3');
print('N features in 70% sample', randomSample70.size());