striker

Given a GeoJSON line, calculate the strike and dip of a best-fit plane for that line.

How it works

The script finds elevation values for each point along the line using the Mapbox Surface API. Then, it generates a list of all the planes that could be defined by any group of three points in the line. Using each potential plane, turf-planepoint compares the true elevation of each point in the line to a projected value on that plane. The plane with the closest match to real elevation values is used and a strike and dip are calculated.

Configuration

In order to use the Mapbox Surface API you must have a Mapbox access token with sufficient permissions to access Mapbox elevation data. You can set your token using an environment variable (MapboxAccessToken) or with a flag when calling the command directly.

Installation and usage

Provides a shell script you can use. Pipe a LineString or MultiLineString into stdin or as a parameter

$ npm install -g striker

$ cat my-line.geojson | striker

$ cat my-line.geojson | striker --token pk.xxx

$ striker '{"type":"Feature","geometry":{"type":"LineString","coordinates":[[-112.32005596160889,36.17280264906953],[-112.31984
13848877,36.17675185235112],[-112.32409000396729,36.176717211082384]]}}'

Or, use it in JavaScript

var striker = require('striker')({
  token: mapboxAccessToken
});

var geojson = {
  type: 'Feature',
  geometry: {
    type: 'LineString',
    coordinates: [
      [-112.32005596160889,36.17280264906953],
      [-112.3198413848877,36.17675185235112],
      [-112.32409000396729,36.176717211082384]
    ]
  }
};

striker(geojson, function(err, plane) {
  console.log('Strike: %s', plane.strike);
  console.log('Dip: %s', plane.dip);
});