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: writeMarkerFile.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/external/ctf
    
    the code of the file until where you have to start completion: function writeMarkerFile(MarkerFile,marker);

%  Version 1.0   27 Oct. 2006

%   Prepares a CTF Markerfile.
%   The MarkerFile format is defined in document CTF MEG File Formats, PN900-0088.

%   Inputs :
%    Structure marker in the format prepared by readMarkerFile.m.  In cases where 
%    only some of the trials of a data set are being written from MATLAB to a data set,
%    be careful to match the trial identification to the data.
%
%    Trial numbering in structure marker starts at 1, but the numbering in the marker
%    file starts at 0.

%    The dataset (i.e. directory) must be created before calling writeMarkerFile.

%  Output : Marker file with name datasetname\Markerfile.mrk

%  Check input marker.

if nargin==0
  fprintf(['writeMarkerFile:  Version 1.0   27 Oct. 2006\n',...
      '\twriteMarkerFile(MarkerFile,marker) creates a CTF dataset MarkerFile ',...
      'from structure array marker.\n',...

    
function writeMarkerFile(MarkerFile,marker);

%  Version 1.0   27 Oct. 2006

%   Prepares a CTF Markerfile.
%   The MarkerFile format is defined in document CTF MEG File Formats, PN900-0088.

%   Inputs :
%    Structure marker in the format prepared by readMarkerFile.m.  In cases where 
%    only some of the trials of a data set are being written from MATLAB to a data set,
%    be careful to match the trial identification to the data.
%
%    Trial numbering in structure marker starts at 1, but the numbering in the marker
%    file starts at 0.

%    The dataset (i.e. directory) must be created before calling writeMarkerFile.

%  Output : Marker file with name datasetname\Markerfile.mrk

%  Check input marker.

if nargin==0
  fprintf(['writeMarkerFile:  Version 1.0   27 Oct. 2006\n',...
      '\twriteMarkerFile(MarkerFile,marker) creates a CTF dataset MarkerFile ',...
      'from structure array marker.\n',...
      '\tStructure array marker is in the format created by function ',...
      'readMarkerFile.\n\n',...
      '\twriteMarkerFile decrements trial numbers by 1 so the first dataset ',...
      'trial in MarkerFile is trial 0.\n\n',... 
      '\tThe MarkerFile format is defined in document "CTF MEG File Formats",',...
      ' PN900-0088.\n\n']);
  return
end


if exist('marker')==0
  fprintf('writeMarkerFile:  Structure marker is not defined.\n');
  return
elseif isempty(marker)
  fprintf('writeMarkerFile:  Structure marker is empty.\n');
  return
elseif ~isstruct(marker)
  fprintf('writeMarkerFile:  Input argument marker is not a structure.\n');
  return
end

%  Check MarkerFile
if exist('MarkerFile')~=1;MarkerFile=char([]);end