Barycentric coordinates of a n-body System

[Topper]

I just need an Idea how I can create an alogrithm to calculate "average position and speed" of a n-body system, to subtract this values from each body.
So the system should be the same, but without any "Offset" for position and speed to the "global frame".
I think I need to calculate the "Barycentric coordinates" and subtract the coordinates from each body right?

Background is, I want to "Normalize" a gravitational system where I have positions and speeds, that it will stay near the "zero - point"...

At wikipedia, I found how to calculate it for 2 boddies.
I need it for x/y/z coordinates and I don't realy know how to calculate it for 3 / 4 / n boddies.
Is it the same formular for speed and position?

Please give me any hints or ideas

---------- Post added at 22:03 ---------- Previous post was at 21:17 ----------

Ha got it myself...

public class GBodySystemNormalizer 
{
	static public void normalizeVectors(List<GBody> gBoddies)
	{
		GBody gbAverage = new GBody();
		List<GBody> validGBoddies = new ArrayList<GBody>();
		double totalMass = 0;
		for (GBody gb : gBoddies)	
		{
			if (gb.mergedObject == null) 
			{
				validGBoddies.add(gb);
				totalMass += gb.m;
			}
		}
		for (GBody gb1 : validGBoddies)
		{
			gbAverage.r[0].add(gb1.r[0].mul(gb1.m/totalMass));
			gbAverage.v[0].add(gb1.v[0].mul(gb1.m/totalMass));
		}
		
		for (GBody gb : validGBoddies)
		{		
			gb.r[0].det(gbAverage.r[0]);
			gb.v[0].det(gbAverage.v[0]);
		}
	}
}