Importing multiple text files into MATLAB

I am trying to import multiple text files into MATLAB and save it as a .mat file after it has been imported. It works when I do it one file at a time by using the following command, for example:

T1_1041 = importdata('20101011_114543_VIN9375_Trigger01.txt');

but when I try to save the file name into a variable and try to use the importdata function with that variable as the file name. It does not work, like below:

myfile = '20101011_114543_VIN9375_Trigger01.txt'
[files,path] = uigetfile('MultiSelect', 'on');

for n=1:length(files);
  myfile = files(n);
  files(n).data=importdata(myfile);
  save files(n).data
end

It gives an error inside the importdata function.

[Jan]

Please use the code formatting to improve the readability. If you get an error, it would be very helpful to post the error message.

Answer 1

[Jan]

Your variable "files" is a cell string, therefore you need curly braces. During the loop you overwrite the original "files" by a struct. The variable "myfile" is overwritten also - it looks really confused.

[filenames, pathname] = uigetfile('MultiSelect', 'on');
filenames = cellstr(filenames);  % EDITED
for n = 1:length(filenames)
  afile = fullfile(pathname, filenames{n});  % EDITED
  data = importdata(afile);
  % Remove the file extension file the name:
  [dummy, afilename] = fileparts(filenames{n});
  save(afilename, 'data');
end

If you want to save all data in one MAT file, explain this again with more details.

[Harshit Coutinho]

ok i tried the code above that you suggested and it still does not work. The error that i get is

??? Error using ==> importdata at 114

Unable to open file.

Error in ==> trial at 12

fi =importdata(files{1});

Let me explain this again. When i run the file it opens a file browser window. I select the files that I want to open. It save those file names in files. I want to then use the stored file names with the importdata function by using the variable files{n} as the file name. But it does not work. But if i type the filename into the importdata function then it works.

[Doug Eastman]

Can you tell us what files{1} is? Just add files{1} with no semicolon on line 12 before the call to importdata.

I would mention that you need to be a little careful because if you only select one file from the dialog it is not a cell array, the filename is stored directly as a string in files. However if this was the problem you were facing I would expect the following error message:

??? Cell contents reference from a non-cell array object.

So there must be something else going on.

[Doug Eastman]

Another question that would cause this problem - do you change directories in the file selection gui?

[Jan]

I've inserted two changes in the code. Please try it again.

Answer 2

[Doug Eastman]

To be more robust to directory changes or single file selections, you might want to use something like the following:

[files,path] = uigetfile('MultiSelect', 'on');

if iscell(files)
  for n = 1:length(files)
    data = importdata(fullfile(path,files{n})); % fullfile including path
    % save data
  end
else
  data = importdata(fullfile(path,files));
  % save data
end