Skip to content
group geojson points into containing polygons
JavaScript
Find file
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.
bin
example
test
.travis.yml
LICENSE
index.js
package.json
readme.markdown

readme.markdown

point-grouper

group geojson points into containing polygons

build status

example

var fs = require('fs');
var path = require('path');
var grouper = require('point-grouper');

var g = grouper();
g.on('region', function (region) {
    console.log('REGION ' + region.name);
    var outfile = path.join(__dirname, 'output', region.name + '.geojson');
    region.pipe(fs.createWriteStream(outfile));
});

process.argv.slice(2).forEach(function (file) {
    var ws = g.createWriteStream();
    fs.createReadStream(file).pipe(ws);
});

Then give point-grouper some files. Here we'll provide oakland city council district boundaries for the polygons and oakland street tree data for the points.

$ mkdir -p output
$ node group.js districts.json trees.geojson
REGION 7
REGION 6
REGION 1
REGION 3
REGION 5
REGION 4
REGION 2

The program will then split up the tree data out into each district file:

$ ls -sh output/
total 41M
9.6M 1.geojson  6.7M 3.geojson  4.6M 5.geojson  4.0M 7.geojson
6.0M 2.geojson  4.9M 4.geojson  4.6M 6.geojson

You can also use the point-grouper command that ships with this module to do the same thing without having to use the API directly:

$ point-grouper districts.json trees.geojson -o output/

usage

usage: point-grouper FILES {-o OUTDIR}

methods

var grouper = require('point-grouper')

var g = grouper(cb)

Create a new grouper.

Optionally provide a cb(err, region) listener for 'error' and 'region' events.

g.createWriteStream()

events

g.on('region', function (region) {})

When a region (any polygon) was read from one of the input files, this event fires with region, a readable stream of geojson data for all of the points contained in the region.

The region stream has these properties:

  • region.index - the numeric index of the region
  • region.name - the property Name if one was present
  • region.feature - the feature data for the region polygon
  • region.coordinates - an array of the points in the region shape

install

With npm, to get the library do:

npm install point-grouper

and to get the point-grouper command do:

npm install -g point-grouper

license

MIT

Something went wrong with that request. Please try again.