ee.Geometry.LineString.centroid

AI-generated Key Takeaways

• The centroid method returns a point at the center of the highest-dimension components of a geometry, ignoring lower-dimensional components.

• The LineString.centroid() method returns a Geometry.

• The maxError argument specifies the maximum error tolerated during reprojection, and the proj argument specifies the output projection.

• Examples are provided in both JavaScript and Python for calculating and displaying the centroid of a LineString.

Returns a point at the center of the highest-dimension components of the geometry. Lower-dimensional components are ignored, so the centroid of a geometry containing two polygons, three lines and a point is equivalent to the centroid of a geometry containing just the two polygons.

Usage	Returns
LineString.centroid(maxError, proj)	Geometry

Argument	Type	Details
this: geometry	Geometry	Calculates the centroid of this geometry.
maxError	ErrorMargin, default: null	The maximum amount of error tolerated when performing any necessary reprojection.
proj	Projection, default: null	If specified, the result will be in this projection. Otherwise it will be in EPSG:4326.

Examples

Code Editor (JavaScript)

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

// Apply the centroid method to the LineString object.
var lineStringCentroid = lineString.centroid({'maxError': 1});

// Print the result to the console.
print('lineString.centroid(...) =', lineStringCentroid);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(lineString,
             {'color': 'black'},
             'Geometry [black]: lineString');
Map.addLayer(lineStringCentroid,
             {'color': 'red'},
             'Result [red]: lineString.centroid');

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]])

# Apply the centroid method to the LineString object.
linestring_centroid = linestring.centroid(maxError=1)

# Print the result.
display('linestring.centroid(...) =', linestring_centroid)

# 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(
    linestring_centroid, {'color': 'red'}, 'Result [red]: linestring.centroid'
)
m