Get center of a list of coordinates

centerCoordinates.js

function centerCoordinates(coordinates) {
	if (coordinates.length === 0) {
		return coordinates;
	}

	let x, y, z;
	x = y = z = 0;

	coordinates.forEach(coordinate => {
		const latitude = (coordinate[0] * Math.PI) / 180;
		const longitude = (coordinate[1] * Math.PI) / 180;

		x += Math.cos(latitude) * Math.cos(longitude);
		y += Math.cos(latitude) * Math.sin(longitude);
		z += Math.sin(latitude);
	});

	x = x / coordinates.length;
	y = y / coordinates.length;
	z = z / coordinates.length;

	const centralLongitude = Math.atan2(y, x);
	const centralSquareRoot = Math.sqrt(x * x + y * y);
	const centralLatitude = Math.atan2(z, centralSquareRoot);

	return [
		(centralLatitude * 180) / Math.PI,
		(centralLongitude * 180) / Math.PI,
	];
}