gistfile1.txt

var data = require('./data/users.json');

function distance(lat1, lon1, lat2, lon2) {
	var radlat1 = Math.PI * lat1/180;
	var radlat2 = Math.PI * lat2/180;
	var radlon1 = Math.PI * lon1/180;
	var radlon2 = Math.PI * lon2/180;
	var theta = lon1 - lon2;
	var radtheta = Math.PI * theta/180;
	var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
	dist = Math.acos(dist);
	dist = dist * 180/Math.PI;
	return dist * 60 * 1.3368159616;
}

data.forEach(function (item) {
	if (distance(53.3381985, -6.2592576, item.latitude, item.longitude) <= 100) {
		console.log(item.user_id);
	}
});