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

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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.

Accepted Answer

Karim on 28 Jun 2022
Edited: Karim on 28 Jun 2022
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)
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');
Error using load
Unable to find file or directory 'data001.mat'.

More Answers (1)

Nitanshu on 28 Jun 2022
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 = {};
[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}));
Hope it helps!


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