How do I implement sort_nat.m a function for opening and reading files?

I am a beginner matlab user and I want to read all files of a certain type in a folder, and save certain pieces of data (in this case line 18) out of the file as a matrix.

I have pieced together this code from various sources. It isn't exactly what I want but it's getting close.

This code will save the data in the wrong order, as the files are being read in the order file001, file015, file002.

Because of this I need to use the sort_nat.m function that I have downloaded and placed in the matlab directory, however I do not know where to implement it.

If you have a better way to write this script or can show me how to implement sort_nat.m that would be great.

Thanks

% Specify the folder where the files live.
myFolder = 'D:\Capstone\TFI Data\2D Curtain test 1';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isdir(myFolder)
  errorMessage = sprintf('Error: The following folder does not exist:\n%s', myFolder);
  uiwait(warndlg(errorMessage));
  return;
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.asA'); % Change to whatever pattern you need.
theFiles = dir(filePattern);

for k = 1 : length(theFiles)
  baseFileName = theFiles(k).name;
  fullFileName = fullfile(myFolder, baseFileName);
  fprintf(1, 'Now reading %s\n', fullFileName);
  % Now do whatever you want with this file name,
  % such as reading it in as an image array with imread()
  fid = fopen(fullFileName,'rt');
data = cell2mat( textscan(fid, '%f', 'HeaderLines', 17, 'collectOutput', true) );
fclose(fid);
V(k)= data(1)

 
end

Answer 1

[Stephen23]

You can download my FEX submission NATSORTFILES here:

https://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort

and also look at the Examples page, which shows how to use it with filenames. Following those examples, your code would be like this:

P = 'D:\Capstone\TFI Data\2D Curtain test 1';
S = dir(fullfile(P,'*.asA'));
S = natsortfiles(S);
for k = 1:numel(S)
    F = fullfile(P,S(k).name);
    fprintf(1,'Now reading %s\n',F);
    fid = fopen(F,'rt');
    C = textscan(fid, '%f', 'HeaderLines', 17, 'collectOutput', true);
    fclose(fid);
    data = cell2mat(C);
    ... the rest of your code
end

[Isaac Brambley]

I had just started looking at natsortfiles as you answered, thank you so much.