earth-distance-js

Pure JS implementation of basic mathmatical solutions to geo-location measurements

Features

• Haversine equation: shortest distance between two geopoints over earth's surface
• Spherical Law of Cosines: An alternative measurement between two geopoints
• Equirectangular Approximation: A high performace alterantive (with accuracy loss) to Haversine
• Bounding Box: Finds the max/min lat/lon values from a centerpoint as a square
• Validation: Checks inputed lat/lon values to be within -90 to 90 and -180 to 180

Installation

Using npm run:

    npm install earth-distance-js

Examples

Haversine

Returns distance in KM

const { haversine } = require('earth-distance-js');

var Newyork = {
    lat: 40.6971,
    lon: -74.2598
  };
var Boston = {
    lat: 42.3140,
    lon: -71.2497
  };
var NewyorkToBoston = haversine(Newyork, Boston);
console.log(NewyorkToBoston);

// --> 308.84810486810926

Spherical Cosine

Returns distance in KM

const { sphericalCosines } = require('earth-distance-js');

var Newyork = {
    lat: 40.6971,
    lon: -74.2598
  };
var Boston = {
    lat: 42.3140,
    lon: -71.2497
  };

var NewyorkToBoston = sphericalCosines(Newyork, Boston);
console.log(NewyorkToBoston);

// --> 308.7849679955355

Equirectangular Eq

Returns distance in KM

const { equirectangular } = require('earth-distance-js');

var Newyork = {
    lat: 40.6971,
    lon: -74.2598
  };
var Boston = {
    lat: 42.3140,
    lon: -71.2497
  };

var NewyorkToBoston = equirectangular(Newyork, Boston);
console.log(NewyorkToBoston);

// --> 339.304994196915

NOTE: equirectangular will be inaccurate over large distances. However, it is more performant than haversine. Over short distances metrics where exact distance does not matter, is generally the best use scenario.

Bounding Box

Returns min/max set of geopoints

const { getBoundingBox } = require('earth-distance-js');

var Newyork = {
    lat: 40.6971,
    lon: -74.2598
  };

var NewyorkBoundBox = getBoundingBox(Newyork, 280);
console.log(NewyorkBoundBox);
// [
//  -77.57817195169761,
//  38.18181720446535,
//  -70.94142804830238,
//  43.212382795534666
// ]

NOTE: when using getBoundingBox remember that the distance inputted is 'horizontal/ vertial' maxima, rather than a 'max radius', the distance of the min/max geopoints will be farther (similar to isosceles right angle triangle);

License

MIT