Merge multiple files containing given string into one mat file

Hello,

How to merge multiple files which names contains given strings (for instance: Name, ECG, data) into one file?

[Ganesh]

I'm sorry, but I am not able to understand the file structure.

1. Each file is a .mat file which contains data of different people. i.e. Same fields, different entries, and you need to combine them into an array
2. Each .mat file has an array corresponding to each field. i.e. one for Name, one for ECG, with index same for each "person"
3. Either of the above, with a different format than .mat

Could you please confirm which one of these describes your data

[DGM]

You've only told us that the filenames vary somehow. You haven't said how the filenames vary, what the file type is, what the files contain, or how their contents should be combined.

Until you attach example files, or otherwise adequately describe what you have and what you want, the answer is "it depends".

Answer 1

[Elzbieta]

Hello,

Finally I figured out the following code:

names = {'Alessandra', 'Alfredo', 'Carla', 'Giulia', 'Ilaria', 'Letizia', 'Lucrezia', 'Mariangela', 'Martina', 'Michela'}

% Get a list of all files in the folder with the desired file name pattern.

for i = 1: length(names)

filePattern = fullfile(myFolder,['*',names{i},'*trial*ECG*data.mat']) % Change to whatever pattern you need.

theFiles = dir(filePattern)

data = [];

for k = 1 : length(theFiles)

new_data = [];

baseFileName = theFiles(k).name;

fullFileName = fullfile(myFolder, baseFileName)

display("new_data")

new_data = load(fullFileName, '-ascii');

size(new_data)

if (isrow(new_data) == 1)

data = [data; new_data'];

else

data = [data; new_data];

end

size(data)

data;

end

outFullFileName = fullfile(myFolder,[names{i},'_trial_ECG_data.txt'])

save(outFullFileName, 'data', '-tabs', '-ascii')

end

Answer 2

[Nipun]

Hi Elzbieta,

I understand that you want to merge multiple .mat files whose names contain specific strings (e.g., "Name", "ECG", "data") into a single .mat file. Below is the MATLAB code to achieve this:

function merge_files_to_matfile(directory, search_strings, output_filename)
    % List all .mat files in the specified directory
    files = dir(fullfile(directory, '*.mat'));
    
    % Initialize a structure to store the merged data
    merged_data = struct();
    
    % Loop through each file and check if it contains any of the search strings
    for file = files'
        for str = search_strings
            if contains(file.name, str{1})
                % Load the data from the file
                file_data = load(fullfile(directory, file.name));
                
                % Merge the data into the merged_data structure
                fields = fieldnames(file_data);
                for i = 1:length(fields)
                    field = fields{i};
                    if isfield(merged_data, field)
                        merged_data.(field) = [merged_data.(field); file_data.(field)];
                    else
                        merged_data.(field) = file_data.(field);
                    end
                end
                break; % No need to check other strings if one matches
            end
        end
    end
    
    % Save the merged data to the specified output file
    save(output_filename, '-struct', 'merged_data');
end

% Example usage:
directory = 'path_to_your_directory';
search_strings = {'Name', 'ECG', 'data'};
output_filename = 'merged_data.mat';

merge_files_to_matfile(directory, search_strings, output_filename);

Explanation

1. Function Definition: The merge_files_to_matfile function takes three arguments:

• directory: The directory containing the .mat files.
• search_strings: A cell array of strings to search for in the filenames.
• output_filename: The name of the output .mat file.

1. Listing Files: The dir function lists all .mat files in the specified directory.
2. File Matching and Merging: The function checks if each file's name contains any of the search strings. If it does, it loads the file and merges its contents into a structure merged_data.
3. Saving Merged Data: The merged data is saved into a single .mat file with the specified output filename.

For more information on the dir and save functions, you can refer to the MathWorks documentation:

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

Hope this helps.

Regards,

Nipun

[DGM]

OP never said the files were .mat files.

The only information we have is that:

1. the file names contain metadata
2. the contents of these unknown files should be crammed into a .mat file

We don't know what the filename format is

We don't know what the file type is

We don't know what the file contents are

We don't know how the contents should be merged.

I usually wait till a question is dead and cold before I assert a blind interpretation, but I guess "dead and cold" is fair to interpret at this point.