function comparativeDistance(x, y) {
	return (
		Math.pow(x[0] - y[0], 2) +
		Math.pow(x[1] - y[1], 2) +
		Math.pow(x[2] - y[2], 2)
	);
}
See https://en.m.wikipedia.org/wiki/Euclidean_distance#Squared_Euclidean_distance