ee.Geometry.Polygon.union

Returns the union of the two geometries.

UsageReturns
Polygon.union(right, maxError, proj)Geometry
ArgumentTypeDetails
this: leftGeometryThe geometry used as the left operand of the operation.
rightGeometryThe geometry used as the right operand of the operation.
maxErrorErrorMargin, default: nullThe maximum amount of error tolerated when performing any necessary reprojection.
projProjection, default: nullThe projection in which to perform the operation. If not specified, the operation will be performed in a spherical coordinate system, and linear distances will be in meters on the sphere.

Examples

Code Editor (JavaScript)

// Define a Polygon object.
var polygon = ee.Geometry.Polygon(
    [[[-122.092, 37.424],
      [-122.086, 37.418],
      [-122.079, 37.425],
      [-122.085, 37.423]]]);

// Define other inputs.
var inputGeom = ee.Geometry.BBox(-122.085, 37.415, -122.075, 37.425);

// Apply the union method to the Polygon object.
var polygonUnion = polygon.union({'right': inputGeom, 'maxError': 1});

// Print the result to the console.
print('polygon.union(...) =', polygonUnion);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(polygon,
             {'color': 'black'},
             'Geometry [black]: polygon');
Map.addLayer(inputGeom,
             {'color': 'blue'},
             'Parameter [blue]: inputGeom');
Map.addLayer(polygonUnion,
             {'color': 'red'},
             'Result [red]: polygon.union');

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)

# Define a Polygon object.
polygon = ee.Geometry.Polygon([[
    [-122.092, 37.424],
    [-122.086, 37.418],
    [-122.079, 37.425],
    [-122.085, 37.423],
]])

# Define other inputs.
input_geom = ee.Geometry.BBox(-122.085, 37.415, -122.075, 37.425)

# Apply the union method to the Polygon object.
polygon_union = polygon.union(right=input_geom, maxError=1)

# Print the result.
display('polygon.union(...) =', polygon_union)

# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(polygon, {'color': 'black'}, 'Geometry [black]: polygon')
m.add_layer(input_geom, {'color': 'blue'}, 'Parameter [blue]: input_geom')
m.add_layer(polygon_union, {'color': 'red'}, 'Result [red]: polygon.union')
m