ee.Geometry.Polygon.union
Returns the union of the two geometries.
Usage | Returns |
---|
Polygon.union(right, maxError, proj) | Geometry |
Argument | Type | Details |
---|
this: left | Geometry | The geometry used as the left operand of the operation. |
right | Geometry | The geometry used as the right operand of the operation. |
maxError | ErrorMargin, default: null | The maximum amount of error tolerated when performing any necessary reprojection. |
proj | Projection, default: null | The 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
// 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
# 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
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Last updated 2023-10-06 UTC.
[null,null,["Last updated 2023-10-06 UTC."],[[["`union()` returns a Geometry representing the combined area of two input geometries."],["The operation can be performed using a specified projection or a spherical coordinate system with linear distances in meters."],["An optional `maxError` parameter controls the tolerance for reprojection errors."],["It takes two geometries as inputs: `left` (the calling geometry) and `right`."]]],["The `union` method combines two geometries, a `left` and a `right`, into a single geometry representing their union. It accepts optional parameters `maxError`, defining the error tolerance during reprojection, and `proj`, specifying the projection for the operation. If `proj` is not set, operations use a spherical coordinate system. Example usage shows defining a Polygon and a BBox as `inputGeom`, then uniting them using `polygon.union()` method and visualize results.\n"]]