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: dcm2LeanVector.m
    path of file: ./repos/LADAC/utilities/axes_transformation
    
    the code of the file until where you have to start completion: function n_g = dcm2LeanVector( M_bg )
% dcm2LeanVector computes the reduced attitude vector in g frame (NED).
%   For more information see [1], section II.B.
% 
% Inputs:
%   M_bg                DCM from g frame to b frame
% 
% Outputs:
%   n_g                 unit vector that points into the -z_b direction
%                       represented in g frame (NED)
% 
% Literature:
%   [1] https://arxiv.org/pdf/2002.07837.pdf
% 
% See also:
%   quatReduced, euler2Dcm, quat2Dcm, dcm2Lean
% 

% Disclamer:
%   SPDX-License-Identifier: GPL-3.0-only
% 
%   Copyright (C) 2020-2022 Yannic Beyer
%   Copyright (C) 2022 TU Braunschweig, Institute of Flight Guidance
% *************************************************************************

% unit vector in body frame (pointing up)
n_b = [ 0; 0; -1 ];

    
function n_g = dcm2LeanVector( M_bg )
% dcm2LeanVector computes the reduced attitude vector in g frame (NED).
%   For more information see [1], section II.B.
% 
% Inputs:
%   M_bg                DCM from g frame to b frame
% 
% Outputs:
%   n_g                 unit vector that points into the -z_b direction
%                       represented in g frame (NED)
% 
% Literature:
%   [1] https://arxiv.org/pdf/2002.07837.pdf
% 
% See also:
%   quatReduced, euler2Dcm, quat2Dcm, dcm2Lean
% 

% Disclamer:
%   SPDX-License-Identifier: GPL-3.0-only
% 
%   Copyright (C) 2020-2022 Yannic Beyer
%   Copyright (C) 2022 TU Braunschweig, Institute of Flight Guidance
% *************************************************************************

% unit vector in body frame (pointing up)
n_b = [ 0; 0; -1 ];

n_g = M_bg' * n_b;

end