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: cart2cyl.m
    path of file: ./repos/matGeom/matGeom/geom3d
    
    the code of the file until where you have to start completion: function varargout = cart2cyl(varargin)
%CART2CYL  Convert cartesian to cylindrical coordinates.
%
%   CYL = cart2cyl(POINT)

    
function varargout = cart2cyl(varargin)
%CART2CYL  Convert cartesian to cylindrical coordinates.
%
%   CYL = cart2cyl(POINT)
%   convert the 3D cartesian coordinates of points POINT (given by [X Y Z]
%   where X, Y, Z have the same size) into cylindrical coordinates CYL,
%   given by [THETA R Z]. 
%   THETA is the arctangent of the ratio Y/X (between 0 and 2*PI)
%   R     can be computed using sqrt(X^2+Y^2)
%   Z     keeps the same value.
%   The size of THETA, and R is the same as the size of X, Y and Z.
%
%   CYL = cart2cyl(X, Y, Z)
%   provides coordinates as 3 different parameters
%
%   Example
%   cart2cyl([-1 0 2])
%   gives : 4.7124    1.0000     2.0000
%
%   See also 
%   angles3d, cart2pol, cart2sph2
%

% ------
% Author: David Legland
% E-mail: david.legland@inrae.fr
% Created: 2006-03-23
% Copyright 2006-2023 INRA - CEPIA Nantes - MIAJ (Jouy-en-Josas)

% process input parameters
if length(varargin)==1
    var = varargin{1};
    x = var(:,1);
    y = var(:,2);
    z = var(:,3);
elseif length(varargin)==3
    x = varargin{1};
    y = varargin{2};
    z = varargin{3};
end