code: public static Quat4d orientation(Point3d[] points) {
  
  		MomentsOfInertia moi = new MomentsOfInertia();
  
  		for (Point3d p : points)
  			moi.addPoint(p, 1.0);
  
  		// Convert rotation matrix to quaternion
  		Quat4d quat = new Quat4d();
  		quat.set(moi.getOrientationMatrix());
  
  		return quat;
  	}
docs: The orientation represents the rotation of the principal axes with
  respect to the axes of the coordinate system (unit vectors [1,0,0],
  [0,1,0] and [0,0,1]).
  <p>
  The orientation can be expressed as a unit quaternion.
  
  @param points
  array of Point3d
  @return the orientation of the point cloud as a unit quaternion