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: ecef2llh.m
    path of file: ./repos/NaveGo/conversions
    
    the code of the file until where you have to start completion: function llh = ecef2llh(ecef)
% ecef2llh:	converts from ECEF coordinates to navigation coordinates
%  (latitude, longitude and height).
%
% INPUTS
%   ecef: Nx3 ECEF coordinates [X Y Z] (m, m, m).
%
% OUTPUTS
%   llh, Nx3 [latitude longitude height] (rad, rad, m)
%   
%   Height is above ellipsoid.
%
%   Copyright (C) 2014, Rodrigo Gonzalez, all rights reserved.
%
%   This file is part of NaveGo, an open-source MATLAB toolbox for
%   simulation of integrated navigation systems.
%
%   NaveGo is free software: you can redistribute it and/or modify
%   it under the terms of the GNU Lesser General Public License (LGPL)
%   version 3 as published by the Free Software Foundation.
%
%   This program is distributed in the hope that it will be useful,
%   but WITHOUT ANY WARRANTY; without even the implied warranty of
%   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%   GNU Lesser General Public License for more details.
%
%   You should have received a copy of the GNU Lesser General Public
%   License along with this program. If not, see
%   <http://www.gnu.org/licenses/>.
%
% References:
%	H. Vermeille. Direct transformation from geocentric
% coordinates to geodetic coordinates. Journal of Geodesy, 2002.
%
%  	R. Gonzalez, J. Giribet, and H. Pati√±o. NaveGo: a
% simulation framework for low-cost integrated navigation systems,
% Journal of Control Engineering and Applied Informatics}, vol. 17,
% issue 2, pp. 110-120, 2015. Eq. 17.
%

    
function llh = ecef2llh(ecef)
% ecef2llh:	converts from ECEF coordinates to navigation coordinates
%  (latitude, longitude and height).
%
% INPUTS
%   ecef: Nx3 ECEF coordinates [X Y Z] (m, m, m).
%
% OUTPUTS
%   llh, Nx3 [latitude longitude height] (rad, rad, m)
%   
%   Height is above ellipsoid.
%
%   Copyright (C) 2014, Rodrigo Gonzalez, all rights reserved.
%
%   This file is part of NaveGo, an open-source MATLAB toolbox for
%   simulation of integrated navigation systems.
%
%   NaveGo is free software: you can redistribute it and/or modify
%   it under the terms of the GNU Lesser General Public License (LGPL)
%   version 3 as published by the Free Software Foundation.
%
%   This program is distributed in the hope that it will be useful,
%   but WITHOUT ANY WARRANTY; without even the implied warranty of
%   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%   GNU Lesser General Public License for more details.
%
%   You should have received a copy of the GNU Lesser General Public
%   License along with this program. If not, see
%   <http://www.gnu.org/licenses/>.
%
% References:
%	H. Vermeille. Direct transformation from geocentric
% coordinates to geodetic coordinates. Journal of Geodesy, 2002.
%
%  	R. Gonzalez, J. Giribet, and H. Pati√±o. NaveGo: a
% simulation framework for low-cost integrated navigation systems,
% Journal of Control Engineering and Applied Informatics}, vol. 17,
% issue 2, pp. 110-120, 2015. Eq. 17.
%
% Version: 003
% Date:    2021/03/18
% Author:  Rodrigo Gonzalez <rodralez@frm.utn.edu.ar>
% URL:     https://github.com/rodralez/navego

x = ecef(:,1);
y = ecef(:,2);
z = ecef(:,3);

% WGS84 model
a = 6378137.0000;	% Earth radius in meters
% b = 6356752.3142;	% Earth semiminor in meters
e = 0.0818191908426;% Eccentricity

p = (x.^2 + y.^2) ./ a^2;
q = ((1-e^2) * z.^2) ./ a^2 ;
r = (p + q - e^4) ./ 6;
s = (e^4 * p .* q) ./ (4 * r.^3);
t = (1 + s + sqrt(s .* (2+s)) ) .^ (1/3);
u = r .* (1 + t + ( 1./t ) );
v = sqrt( u.^2 + q .* e.^4);
w = e.^2 .* ( u + v - q ) ./ ( 2 .* v );
k = sqrt( u + v + w.^2 ) - w;

D = k .* sqrt(x.^2 + y.^2) ./ (k + e.^2);

% Latitude
%     llh(1) = 2 * atan((z /(D+sqrt(D^2 + z^2))));
lat = atan2(z , D);

% Longitude
%     llh(2) = 2 * atan((y /(x+sqrt(x^2 + y^2))));
lon = atan2(y , x);

% Altitude
h = (k + e.^2 -1) ./ k .* (sqrt(D.^2 + z.^2));

llh = [lat lon h];
end