add file to matlab using last date

I have a bunch of files in a folder, with names that look like this:

squad1_1910_St4_Se8
squad1_1910_St2_Se3
squad1_1910_St1_Se6
squad1_1910_St4_Se5

I have a code that automatically updates the file using regexprep, amongst other things. right now, the code chooses the file with user input, for instances:

root = 'E:\MATLAB';
user_input_squad = input('please enter squad number: ', 's');
user_input_experiment = input('please enter experiment name: ', 's');
user_input_stage = input('please enter stage: ', 's');
user_input_session = input('Please enter session: ', 's');
file = fullfile(root, sprintf('squad%s_1910_EXP%s_St1_Se%s', user_input_squad, user_input_experiment, user_input_session));

Is there a way for matlab to pull the last file added, without the need for user input? something that sorts the directory by date, and chooses the first one?

this would have to be for a bunch of files, as they change periodically. for instance, there would be 2 files named

squad1_1910_St4_Se8

the squad number is the only chnage to the name. so if a user inputs squad 2, is there a way to automatically pick only the latest squad 2 file, without touching the others?

Answer 1

[Image Analyst]

You can use dir() to get the file date/time stamps.

folder = pwd; % Whatever folder you want.
filePattern = fullfile(folder, '**\*.txt')
dirListing = dir(filePattern)
fileDates = [dirListing.datenum]
% Sort in descending order (most recent, latest date as item #1)
[sortedDates, sortOrder] = sort(fileDates, 'Descend')
% Sort files in that order.
dirListing = dirListing(sortOrder); % Rearrange using the new sort order.
fileNames = {dirListing.name}
% Let user know the most recent file.
message = sprintf('The most recent file is %s.\nIt has a date time stamp of %s', ...
	fileNames{1}, datestr(dirListing(1).datenum))
fprintf('%s\n', message);
uiwait(helpdlg(message));

Let me know if it works for you (after obvious modifications of course).

[avram alter]

In your code, the line

filePattern = fullfile(folder, '**\*.txt')

should be edited by me to include the names, or that some syntax that lets matlab know its just some .txt file?

also, this folder 4 different ypes of experimental files in it, and each type will need to be automaticallly chosen at a specific time. each type is for a different squad number, but I only want the latest file for that squad to be brought up. there might be newer files for a different squad though.

[Image Analyst]

You can change the filePattern to be whatever you like.

You can parse the filenames however you want to include or exclude particular files for analysis.

[avram alter]

ah, So if I wanted it to search for the latest file with the word 'squad1' appearing in the name of the file, how would I do that?

[Image Analyst]

Let's say you're in a loop where you want to find only the ones you want - that contain some string in the filename. Then do

numFiles = length(fileNames);
filesIWant = false(numFiles, 1);
for k = 1 : numFiles
    if contains(fileNames{k}, 'squad1', 'IgnoreCase', true)
        % Add it to our list.
        filesIWant(k) = true; % Mark this one for inclusion.
    else
        % File name does not contain 'squad1' so nothing to do.
        continue;    % Skip to bottom of loop
    end
end
% Extract only the ones we want
fileNames = fileNames(filesIWant);

[avram alter]

thanks for all the help so far! how would I insert the newest bit of code into the one that looks of it using the latest date? I don't know matlab so well, so I apologize if that is an obvious question.

[Image Analyst]

If you already have identified the most recent file's name, then you can simply see if that filename contains 'squad1' by using contains():

if contains(mostRecentFileName, 'squad1', 'IgnoreCase', true)
    % Then the most recent file contains the string 'squad1' in its name.
end