Simple Geomath

Minimalist library for math involving latitude and longitude.

Installation

npm install --save simple-geomath

API

View full documentation.

Sample Usage

import * as Geo from "simple-geomath";

const losAngeles = { latitude: 34.0522, longitude: -118.2437 };
const newYork = { latitude: 40.7128, longitude: -74.0059 };
Geo.sphericalDistance(losAngeles, newYork);
// 3.944e6, the distance between Los Angeles and New York in meters.

Geo.latLngToCartesian(losAngeles, newYork);
// { x: -3.728e6, y: -7.406e5 }
// These are the coordinates of Los Angeles in a coordinate system centered at
// New York and with meter units. In other words, Los Angeles is ~3700 km west
// and ~740 km south of New York.

To see more available functions, view the full documentation.

Current Limitations

This library is focused on the use case of converting a small section of the Earth to Cartesian coordinates. As such, there are several limitations:

• Projections are inaccurate over large areas. This is a limitation of all projections of spherical coordinates onto Cartesian. See Map Projection on Wikipedia.
• Projections of regions containing the north or south pole are wonky. I recommend you stay away.
• The 180° longitude line (where longitude switches from +180° to -180°) causes problems for the sphericalDistance function and for projections. I recommend you stay away from it too.

Copyright © 2016 David Philipson