Run multiple data files from a directory using function in .m file

I am a beginner to coding, so I need clear explanations of any possible answers to my question.

I have a folder (labeled as 'FolderName' in the script below) that is full of many subfolders with names like "2YYY-MM-DD". Each of those "YYYY-MM-DD" subfolders contain a data file with the extention ".eod". I have a function in a .m file (labeled as 'function_name' in the script below). What I am wanting to do is run the 'function_name' script for each of those .eod files. The 'function_name' script creates a few plots, and I want each of those plots to be saved into those "YYYY-MM-DD" original folders. Instead of having to run .eod file by file, I want it done in one swoop. This code below is not spitting back errors, but it is also not saving those plots in those respective folders. The 'function_name' script runs perfectly if I simply do the command line "function_name('data_file_name.eod')".

Help would be greatly appreciated!

clear all
close all

parent = '\FolderName';                    
folders = dir([parent, '\2*']);
folders = char({folders.name});
 
fileNames = {};
count = 1;
for i = folders
    files = dir([parent, i, '\*.eod']);
    fileNames(count) = {files.name};
    count = count + 1;
end
 
fileNames = string(fileNames);

for i = fileNames
    function_name(char(i));
end

Answer 1

[Image Analyst]

You can't do it all in one swoop. You're going to have to have a loop and open each .eod file and process it one at a time. Tomething like this, adapted from the FAQ:

% Specify the folder where the files live.
topLevelFolder = '\FolderName'; % or wherever, like 'C:\Users\yourUserName\Documents\My Pictures';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(topLevelFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', topLevelFolder);
    uiwait(warndlg(errorMessage));
    topLevelFolder = uigetdir(); % Ask for a new one.
    if topLevelFolder == 0
        % User clicked Cancel
        return;
    end
end
% Get a list of all files in the folder with the desired file name pattern.
% The double * is the key to recursing into subfolders.
filePattern = fullfile(topLevelFolder, '**/*.eod'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
% Optional : If you want all the full file names in one variable, do the line below.
allFileNames = fullfile({theFiles.folder}, {theFiles.name})';
for k = 1 : length(theFiles)
    % Get the name of this file.
    baseFileName = theFiles(k).name;
    thisFolder = theFiles(k).folder;
    fullFileName = fullfile(thisFolder, baseFileName); % or allFileNames{k}
    fprintf(1, 'Now reading file: %s\n', fullFileName);
    % Now do whatever you want with this file name,
    % such as reading it in and plotting something.
    % Now save the plot in a PNG folder in the same folder.
    [~, baseFileNameNoExt, ~] = fileparts(baseFileName);
    outputFullFileName = fullfile(thisFolder, [baseFileNameNoExt, '.png']);
    fprintf(1, 'Now saving plot : %s\n\n', outputFullFileName);
    exportgraphics(gca, outputFullFileName);
end

[Ja Bi]

I got it working :)