ee.Geometry.Polygon.centroid

  • centroid() returns the center point of the highest-dimension components of a geometry, ignoring lower dimensions.

  • It is applicable to Polygon geometries and can be customized with maxError for reprojection tolerance and proj for output projection.

  • The result is a new Geometry object representing the calculated centroid.

  • If proj is not specified, the centroid coordinates will be in EPSG:4326.

 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.

UsageReturns
Polygon.centroid(maxError, proj)Geometry
ArgumentTypeDetails
this: geometryGeometryCalculates the centroid of this geometry.
maxErrorErrorMargin, default: nullThe maximum amount of error tolerated when performing any necessary reprojection.
projProjection, default: nullIf specified, the result will be in this projection. Otherwise it will be in EPSG:4326.

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]]]);

// Apply the centroid method to the Polygon object.
var polygonCentroid = polygon.centroid({'maxError': 1});

// Print the result to the console.
print('polygon.centroid(...) =', polygonCentroid);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(polygon,
             {'color': 'black'},
             'Geometry [black]: polygon');
Map.addLayer(polygonCentroid,
             {'color': 'red'},
             'Result [red]: polygon.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 Polygon object.
polygon = ee.Geometry.Polygon([[
    [-122.092, 37.424],
    [-122.086, 37.418],
    [-122.079, 37.425],
    [-122.085, 37.423],
]])

# Apply the centroid method to the Polygon object.
polygon_centroid = polygon.centroid(maxError=1)

# Print the result.
display('polygon.centroid(...) =', polygon_centroid)

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