geojson-polygon-center

A simple function that finds the central point of a GeoJSON polygon.

Install it with npm install geojson-polygon-center.

``javascript
> var polygonCenter = require('geojson-polygon-center')
> var geojsonFeatureCollection = {
... "type": "FeatureCollection",
... "features": [
... {
..... "type": "Feature",
..... "properties": {},
..... "geometry": {
....... "type": "Point",
....... "coordinates": [
....... -7.734374999999999,
....... 46.07323062540838
....... ]
....... }
..... },
... {
..... "type": "Feature",
..... "properties": {},
..... "geometry": {
....... "type": "Polygon",
....... "coordinates": [
....... [
....... [
....... -7.734026312828064,
....... 46.07364371067343
....... ],
....... [
....... -7.73364007472992,
....... 46.0733962320346
....... ],
....... [
....... -7.73359715938568,
....... 46.07358230630263
....... ],
....... [
....... -7.733838558197021,
....... 46.073781405074676
....... ],
....... [
....... -7.734026312828064,
....... 46.07364371067343
....... ]
....... ]
....... ]
....... }
..... }
... ]
... }
> var point = geojsonFeatureCollection.features[0]
> point.geometry.type
'Point'
> var center = polygonCenter(polygon.geometry)
> center
{ type: 'Point', coordinates: [ 0, 0 ] }
>
> var polygon = geojsonFeatureCollection.features[1]
> polygon.geometry.type
'Polygon'
> var center = polygonCenter(polygon.geometry)
> center
{ type: 'Point',
coordinates: [ -7.733811736106873, 46.07358881855464 ] }
``