fences-slicer

fences-slicer

Split large geojson file into smaller region files

install

Note: you will need node and npm installed first. The easiest way to install node.js is with nave.sh by executing [sudo] ./nave.sh usemain stable

npm install fences-slicer

usage

standalone utility

When using fences-slicer from the command line, it expects the following config parameters in order to do its job.

Name	Description
inputDir	path to the directory containing geojson input files that need to be split into regions. Only GEOJSON files will be processed, all others will be skipped. Input files will not be modified.
outputDir	path to an existing directory that will contain output files after the slicer is done slicing.
regions	JSON array of regions to extract out of the input files. Each region object must contain name and box properties. See sample config file for details.

The expected parameters can be specified via a config file like so:

$ fences-slicer --config=./etc/config.json

sample config file contents

{
  "inputDir": "/some/dir/planet-latest-fences",
  "outputDir": "/some/dir/planet-latest-fences-regions",
  "regions": [
    {
      "name": "USA",
      "box": {
        "left": -124.848974,
        "bottom": 24.396308
        "right": -66.885444,
        "top": 49.384358
      }
    }
  ]
}

If not using a config file, or using a config file but need to override a particular parameter do this:

$ fences-slicer --inputDir=/path/different/from/config --config=./etc/config.json

dependency module

When using fences-slicer in your node.js package as dependency, you need to provide an input file and an array of regions, where each region has an output file and box. See example below.

var slicer = require('fences-slicer');

var inputFile = '/some/dir/planet-fences/planet-level-2.geojson';

var regions = [{
  outputFile: '/some/dir/USA-fences/USA-level-2.geojson',
  box: {
    left: -124.848974,
    bottom: 24.396308
    right: -66.885444,
    top: 49.384358
  }
}];

slicer.extractRegions(inputFile, regions, function (exitCode) {
  console.log('hello fence slices!');
});

coverage

$ npm run coverage

test

$ npm test