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: cat_stat_check_cov2.m
    path of file: ./repos/ExploreASL/External/SPMmodified/toolbox/cat12
    
    the code of the file until where you have to start completion: function varargout = cat_stat_check_cov2(job)
% cat_stat_check_cov 
% _________________________________________________________________________
% Function to check covariance and image quality across samples.
% Use the CAT GUI or SPM batch mod for initialization.
%
% Selected volumes have to be in the same orientation with same voxel 
% size and dimension (e.g., spatially registered images), whereas surfaces  
% have to be same size (number of vertices; i.e., resampled surfaces).
%
% varargout = cat_stat_check_cov(job)
%
%  job           .. spm job structure
%    .data_vol   .. volume input files
%    .data_surf  .. surface input files 
%    .c          .. nuisance variables (cell)
%   [.gap]       .. gap between slices (in case of volume input)
%  varargout     ..
%
% _________________________________________________________________________
% Christian Gaser & Robert Dahnke
% $Id: cat_stat_check_cov2.m 1
    
function
  cscc.H.dcm = datacursormode(cscc.H.figure);
  set(cscc.H.dcm,'UpdateFcn',@myupdatefcn,'SnapToDataVertex','on','Enable','on');

  
  % create two-area colormap
  colormap([jet(64); gray(64)]);

  
  % add colorbar without ticks and colorbar image
  cscc.H.cbar = axes('Position',cscc.pos.cbar,'Parent',...
    cscc.H.figure,'Visible','off');
  image(cscc.H.cbar,1:64); set(get(cscc.H.cbar,'children'),...
    'HitTest','off','Interruptible','off');
  set(cscc.H.cbar,'Ytick','','YTickLabel',''); 

  
  % set correlation matrix image as image
  cscc.H.corr = axes('Position',cscc.pos.corr,'Parent',cscc.H.figure,...
    'Color',cscc.display.figcolor,'Ytick','','YTickLabel','',...
    'XTickLabel','','XTick','','XTickLabel','');
  image(cscc.H.corr,64 * tril(cscc.data.YpY)); axis image;

  
  % scatter plot 
  if cscc.H.isxml
    cscc.H.scat(1) = axes('Position',cscc.pos.corr,'Parent',cscc.H.figure, ...
      'visible','off','Box','on','Color',[0.85 0.85 0.85]);

    if cscc.job.expertgui
      cscc.H.scat(2) = axes('Position',cscc.pos.corr,'Parent',cscc.H.figure, ...
      'visible','off','Box','on','Color',[0.85 0.85 0.85]);
    end