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: plgndr.m
    path of file: ./repos/fieldtrip/private
    
    the code of the file until where you have to start completion: function [varargout] = plgndr(varargin)

% PLGNDR associated Legendre function
    
function from GNU Scientific Library

% Copyright (C) 2002, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org
% for the documentation and details.
%
%    FieldTrip is free software: you can redistribute it and/or modify
%    it under the terms of the GNU General Public License as published by
%    the Free Software Foundation, either version 3 of the License, or
%    (at your option) any later version.
%
%    FieldTrip 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 General Public License for more details.
%
%    You should have received a copy of the GNU General Public License
%    along with FieldTrip. If not, see <http://www.gnu.org/licenses/>.
%
% $Id$

% compile the missing mex file on the fly
% remember the original working directory
pwdir = pwd;
pwdir_ressetter=onCleanup(@()cd(pwdir));

% determine the name and full path of this function
funname = mfilename('fullpath');
mexsrc  = [funname '.c'];
[mexdir, mexname] = fileparts(funname);

mexfullpath=fullfile(mexdir,sprintf('%s.%s',mexname,mexext()));
disp(mexfullpath);
has_mex_func=@()exist(mexfullpath,'file');

if ~has_mex_func()
  % try to compile the mex file on the fly
  ft_warning('trying to compile MEX file from %s', mexsrc);
  cd(mexdir);
  mex(mexsrc);

  if ~has_mex_func()
    ft_error('could not locate / compile MEX file for %s in %s', ...
                mexname, mexfullpath);
  end