ee.Geometry.LineString.union

  • Returns a Geometry representing the union of two geometries.

  • Accepts a right-hand Geometry operand, an optional maximum error margin for reprojection, and an optional projection.

  • Performs the union operation in spherical coordinates with linear distances in meters on the sphere if no projection is specified.

  • Can be applied to LineString, and likely other Geometry types, to combine with other geometries like bounding boxes.

 Returns the union of the two geometries.

UsageReturns
LineString.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 LineString object.
var lineString = ee.Geometry.LineString([[-122.09, 37.42], [-122.08, 37.43]]);

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

// Apply the union method to the LineString object.
var lineStringUnion = lineString.union({'right': inputGeom, 'maxError': 1});

// Print the result to the console.
print('lineString.union(...) =', lineStringUnion);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(lineString,
             {'color': 'black'},
             'Geometry [black]: lineString');
Map.addLayer(inputGeom,
             {'color': 'blue'},
             'Parameter [blue]: inputGeom');
Map.addLayer(lineStringUnion,
             {'color': 'red'},
             'Result [red]: lineString.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 LineString object.
linestring = ee.Geometry.LineString([[-122.09, 37.42], [-122.08, 37.43]])

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

# Apply the union method to the LineString object.
linestring_union = linestring.union(right=input_geom, maxError=1)

# Print the result.
display('linestring.union(...) =', linestring_union)

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