Geo centroid aggregation

Geo centroid aggregation #

A metrics aggregation computing the centroid (mean latitude and longitude) of all geo_point values.

How it works #

The engine sums latitudes and longitudes across the bucket’s geo_point values and divides by the count:

{
  "location": { "lat": .., "lon": .. },
  "count": 15
}

• The mean is arithmetic per axis (a planar average, not spherical) — exact enough at city or country scale, drifting only for extents that cross the 180th meridian or span hemispheres.
• Every parseable point counts once; there is no weight field. The result is null when the bucket holds no points.
• Under distributed fan-out the coordinator keeps its own shard’s value (geo metrics have no mergeable intermediate), so single-node results are the exact ones.
• Like every geo_point consumer, the aggregation sees points normalized at ingestion: {"lat": .., "lon": ..}, [lon, lat] (longitude first) or a "lat,lon" string, all stored as two-dimensional BKD points.

Examples #

Returns the count of points and their centroid — the natural center point for map placement. Over the 15 places: count: 15, location about {lat 31.7484, lon 111.2181}.