How to extract one data from various mat files to one txt file

My code generates various mat files. I know how to extract one specific data from mat to txt :

Data = load('data001.mat','Vol');
DataField = fieldnames(Data);
dlmwrite('data.txt', Data.(DataField{1}));

But I do not know how to extract the same 'Vol' data of different data00x.mat to the same data.txt.

Thank you for your help.

Answer 1

[Karim]

assuming you want to append the data to the same text file, you can generate the name of the file in a loop:

numFiles = 10;
for i = 1:numFiles
    currFile = sprintf( 'data%03d.mat', i)
end

currFile = 'data001.mat'

currFile = 'data002.mat'

currFile = 'data003.mat'

currFile = 'data004.mat'

currFile = 'data005.mat'

currFile = 'data006.mat'

currFile = 'data007.mat'

currFile = 'data008.mat'

currFile = 'data009.mat'

currFile = 'data010.mat'

so the full routine would be something like (note that it won't work here since the data files are not attached)

numFiles = 10;
for i = 1:numFiles
    currFile = sprintf( 'data%03d.mat', i);
    Data = load(currFile,'Vol');
    DataField = fieldnames(Data);
    dlmwrite('data.txt', Data.(DataField{1}), '-append');
end

Error using load
Unable to find file or directory 'data001.mat'.

[Anthony]

It worked, thank you so much.

Answer 2

[Nitanshu]

Hi Anthony

Probably you could take a reference from below code.

% where directory name is the name of directory where all your mat files
% are present.
directory_instance = dir('directory_name');
file_names = {directory_instance.name};
[row_size, col_size] = size(file_names);

for i = 1: col_size
    file_name = string(file_names(1, i))
    Data = load(file_name,'Vol');
    DataField = fieldnames(Data);
    dlmwrite('data.txt', Data.(DataField{1}));
end

Hope it helps!