x = dir ('*.txt') does return a struct but it is a struct of information about the files, not a struct of the data. It basically tells you want the names of the files are (and sizes and last modified and things like that.) You still need to do the loading.
For example,
dinfo = dir('*.txt');
for K = 1 : length(dinfo)
thisfilename = dinfo(K).name; %just the name
thisdata = load(thisfilename); %load just this file
fprintf( 'File #%d, "%s", maximum value was: %g\n', K, thisfilename, max(thisdata(:)) ); %do something with the data
end
If you already know the names then you don't need to use dir() to tell them to you. For example,
for K = 1 : 42
thisfilename = sprintf('qwerty_%04d.txt', K);
thisdata = load(thisfilename); %load just this file
fprintf( 'File #%d, "%s", maximum value was: %g\n', K, thisfilename, max(thisdata(:)) ); %do something with the data
end
to load qwerty_0001.txt, qwerty_0002.txt ... qwerty_0042.txt
