Incrementing File names access

Hi all, I am facing trouble with reading file names in Matlab. My file names are like 05170201.001, 05170201.002, 05170201.003, 05170201.004. For every iteration I need to read a new file followed by the previous one.Every time the new file name just changes in the last two digits. So, can anybody please explain me how to do this.These are text files and the file number is numerous and I am not able to figure out the logic. Can anybody suggest.

Also one more question. While I concatenate two string say '05' and '010301' I get '05010301'. Once I convert this to number using str2num I get 5010301. The first number 0 is missing and I don't want this to happen. Can anybody suggest.

Any Help is sincerely appreciated.

Regards,

Naveen BM

Answer 1

[Image Analyst]

Here's some fairly robust code:

filepattern = fullfile(pwd, '*.0*')
folderInfo  = dir(filepattern)
% Sort filenames in case OS doesn't return them in sorted order.
[baseFileNames, sortOrder] = sort({folderInfo.name});
% Sort folderInfo the same way so they stay synced.
folderInfo = folderInfo(sortOrder);
% User wants to "read a new file followed by the previous one"
% so process files in REVERSE order. 
% (Could also sort "decending" and do for loop in the forward order).
for k = length(baseFileNames) : -1 : 1
  fullFileName = fullfile(folderInfo(k).folder,baseFileNames{k});
  % Get the extension
  [folder, baseFileNameNoExt, ext] = fileparts(fullFileName);
  dblBaseName = str2double(baseFileNameNoExt); % If needed for some reason.
  dblExt = str2double(ext(2:end));
  if isnan(dblExt)
    % extension is not a number
    fprintf('    Skipping %s.\n', fullFileName);
    continue;
  end
  fprintf('Now processing %s.\n', fullFileName);
  % Else the extension is a number so do something with the file.
end

When you convert the base file name to a number, the leading zero doesn't matter. The number 05010301 is the same as the number 5010301. If you want the zero there for some reason, like to print to the command window with fprintf() like I did, then you'll need to keep it as a string.

[Naveen Bandi]

Thank You, I got it working... :)

Answer 2

[KL]

If your text files are in the same folder, then use dir,

https://www.mathworks.com/help/matlab/ref/dir.html

 folderInfo  = dir('yourFolderName/*.txt');

This will return the filenames and some more properties of the text files. If you want to store the filenames alone in a cell array,

 fileNames = {folderInfo.name};

Now that your file names are in this cell array, you can loop through it to do whatever you want,

 for fno = 1:numel(fileNames)
   currentFileName = fileNames{1};
   %your operations
 end

[Naveen Bandi]

Thank You KL,

I got it working Thanks for your time.....