node-vincenty

Repackaged some vanilla js that calculates metric distance between two latitude and longitude coordinates based on Chris Veness' script here:

http://www.movable-type.co.uk/scripts/latlong-vincenty.html http://www.movable-type.co.uk/scripts/latlong-vincenty-direct.html

The module exports two functions: distVincenty(lat1, long1, lat2, long2, callback) which accepts four parameters representing the latitude and longitude of the input coordinates. destVincenty(lat1, lon1, brng, dist) which calculates the destination point given the starting latitude and longitude with a given bearing and distance

Install:

npm install node-vincenty

Usage:

var vincenty = require('node-vincenty');

Examples:

// these are synchronous
console.log( vincenty.distVincenty(30.5, -100.6, 31.7, -101.8) );
console.log( vincenty.destVincenty(30.5, -100.6, 175518.816, -40.4035) );

// these are asynchronous
vincenty.distVincenty(30.5, -100.6, 31.7, -101.8, function (distance) {
    console.log(distance);
});

vincenty.distVincenty(30.5, -100.6, 31.7, -101.8, function (distance, initialBearing, finalBearing) {
    console.log(distance, initialBearing, finalBearing);
});

vincenty.destVincenty(30.5, -100.6, 175518.816, -40.4035, function (lat, lon, finalBearing) {
    console.log(lat, lon, finalBearing);
});

Outputs:

{ distance: '175518.816',
  initialBearing: -40.40353176919702,
  finalBearing: -41.02342255854039 }
{ lat: 30.50034497548687,
  lon: -100.59986425485471,
  finalBearing: -161.1839311037904 }
175518.816
175518.816 -40.40353176919702 -41.02342255854039
30.50034497548687 -100.59986425485471 -161.1839311037904