JavaScript Distance Between Coordinates #javascript #map

distance.js

/**
 * Returns the distance bewteen 2 coordinates.
 * @param {Object} from - Object with lat and lng
 * @param {Object} to - Object with lat and lng
 * @return {float}
 */
function distance(from, to) {
    const {atan2, cos, sqrt, sin} = Math;
    // @note - radius of the planet earth in meters
    const R = 6378137;
    const toRad = Math.PI / 180;
    const dLat = (to.lat - from.lat) * toRad;
    const dLng = (to.lng - from.lng) * toRad;
    const a = sin(dLat / 2) * sin(dLat / 2) + cos(from.lat * toRad) * cos(from.lat * toRad) * sin(dLng / 2) * sin(dLng / 2);
    const c = 2 * atan2(sqrt(a), sqrt(1 - a));
    return R * c;
}