You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: rbody.m
    path of file: ./repos/MSS/GNC
    
    the code of the file until where you have to start completion: function [MRB,CRB] = rbody(m,R44,R55,R66,nu2,r_bp)
% [MRB,CRB] = rbody(m,R44,R55,R66,nu2,r_bp) computes the 6x6 rigid-body 

    
function [MRB,CRB] = rbody(m,R44,R55,R66,nu2,r_bp)
% [MRB,CRB] = rbody(m,R44,R55,R66,nu2,r_bp) computes the 6x6 rigid-body 
% mass and Coriolis-centripetal matrices for an arbitrariliy point P with
% respect to the CO (coordinate origin of the GNC system). If r_bp = [0 0 0]' 
% the CG coincides with the CO and the matrices MRB and CRB are computed 
% in the CO = CG. Else if the distance vector from the CO to the CG is 
% r_bg = [xg, yg, zg]' use r_bp = r_bg.
%
% [MRB,CRB] = rbody(m,R44,R55,R66,nu2,[0, 0, 0]') computes MRB and CRB in CG
% [MRB,CRB] = rbody(m,R44,R55,R66,nu2,r_bg) computes MRB and CRB in CO
%
% In general nu = [u, v, w, p, q, r]' but for a rigid body there exists a
% CRB matrix which only depend