How to pass a “.mat” file as an argument of user defined function?

Please write demo code.

Answer 1

[Walter Roberson]

function listvars(matfilename)
  if ~ischar(matfilename) || ~exist(matfilename,'file')
    error('argument must be the name of an existing file');
  end

    try
      datastruct = load(matfilename);
    catch
      error('Failed in loading from file, might not be real .mat file');
    end

    fn = fieldnames(datastruct);

    if isempty(fn)
      fprintf('File loaded but it had no variables stored in it\n');
    else
      nv = length(fn);
      fprintf('File "%s" contains the following %d variable(s)\n', matfilename, nv);
      for K = 1 : nv
        thisvarname = fn{K};
        thiscontent = datastruct.(thisvarname);
        fprintf('variable "%s", class "%s"\n', thisvarname, class(thiscontent));
      end
    end