Centroid

The centroid function of Turf's measurement module computes the geometric center (centroid) of a GeoJSON feature.

Parameters

• geojson (GeoJSON Feature): the input feature for which the centroid is to be calculated.

Return Value

• coords (Array): an array containing the [longitude, latitude] coordinates of the centroid.

Example

var centroid = require('@turf/measurement').centroid;

var polygon = {
  type: 'Feature',
  properties: {},
  geometry: {
    type: 'Polygon',
    coordinates: [[
      [-77.031669, 38.878605],
      [-77.029609, 38.881946],
      [-77.020339, 38.884084],
      [-77.025661, 38.878605],
      [-77.031669, 38.878605]
    ]]
  }
};

var center = centroid(polygon);
console.log(center); // [-77.025664, 38.87988]

Algorithm

The centroid computation algorithm follows the approach described in the Geospatial Data Abstraction Library (GDAL) documentation. Essentially, the polygon is divided into a grid of fine-grained points, and the centroid is calculated as the average of all points weighted by the area of each cell that the point falls within.

References

• Geospatial Data Abstraction Library (GDAL) documentation
• Turf.js documentation