This is a fork of cmoncrief/geodist

A fast and simple geographical distance calculator. This module calculates "as the crow flies" distance between two points using the haversine formula.

Usage

  var geodist = require('geodist')
    , dist = geodist({lat: 41.85, lon: -87.65}, {lat: 33.7489, lon: -84.3881});
  console.log(dist) //=> 587

API

geodist(start, end, [options]): Retrieve geographic distance between start and end decimal lat/lon coordinates.

The following options are supported:

• unit - Return results in the unit of measurement. Defaults to meters, see below for available types.
• format - Return results as a string with the measurement type. Defaults to false.
• exact - Return exact results as a floating point. Defaults to false.
• limit - Specify a maximum distance here and true will be returned if the distance is less, or false if it is exceeded.

The following types are accepted in the unit option:

• miles or mi
• yards
• feet
• kilometers or km
• meters or m

  var geodist = require('geodist')
    , tokyo = {lat: 35.6833, lon: 139.7667}
    , osaka = {lat: 34.6603, lon: 135.5232};

  geodist(tokyo, osaka)                                // => 402092
  geodist(tokyo, osaka, {exact: true, unit: 'km'})     // => 402.09212137829695
  geodist(tokyo, osaka, {format: true, unit: 'feet'})  // => 1319614 feet
  geodist(tokyo, osaka, {limit: 200})                  // => false
  geodist(tokyo, osaka, {limit: 250})                  // => true

Thanks to Movable Type for supplying the initial JavaScript implementation of the haversine formula that this is based on.