Merge specific text files

I have a code that for each iteration creates specific files with names :

M1_mR1.txt,...,M1_mr100.txt, and

M2_mR1.txt,..., M2_mR100.txt.

After that I would like to merge all the files that Have prefix M1_.....txt into one file and all the files that Have prefix M2_.....txt into one file.

How could I do this?

[KSSV]

What data each file has?

[Ivan Mich]

Each file has 4 columns and one line. Each file has numbers

[Ivan Mich]

I am uploading one

Answer 1

[Stephen23]

You will need two loops, the outer loop for M1, M2, etc, and the inner loop for the files R1,R2,R3,...R100, e.g.:

D  = 'path to the directroy where the files are saved';
Mn = 3;   % number of groups.
Rn = 100; % number of files in each group.
for Mk = 1:Mn % M1, M2, ...
    C = cell(1,Rn); % preallocate cell array for this group
    for Rk = 1:Rn % R1, R2, ... R100
        F = sprintf('M%u_mR%u.txt',Mk,Rk);
        C{Rk} = dlmread(fullfile(D,F))
    end
    M = vertcat(C{:}); % create one matrix from entire group
    F = sprintf('M%u_ALL.txt',Mk);
    dlmwrite(F,M) % save
end

Of course you do not have to use dlmread and dlmwrite: you can trivially change the file importing/exporting functions for something more suitable, or that you have a preference for, or that you think is fancier.

Note that this answer will actually concatenate the file data in the order R1,R2,R3,...R100.

Answer 2

[KSSV]

% to read files starting with M1
txtFiles = dir("M1*.txt") ; 
N = length(txtFiles) ; 
A = zeros(N,4) ; 
for i = 1:N
    a = importdata(txtFiles(i).name) ; 
    A(i,:) = a ; 
end

[Ivan Mich]

Thank you, but the point is that I would like to make merged files, depending on the first two letters. For example If I had multiple files, such as: M1*.txt, M2*.txt, M3*.txt etc , how could create automatic three merged files? I mean I would like to make a loop for ALL possible files.

Could you help me?

[KSSV]

Yes make loop for each M1, M2 and M3.

[Ivan Mich]

How could I do it?

[Stephen23]

Note that this answer will concatenate the file data in this order:

M1_mR1.txt
M1_mR10.txt
M1_mR100.txt
M1_mR11.txt
M1_mR12.txt
M1_mR13.txt
M1_mR14.txt
M1_mR15.txt
M1_mR16.txt
M1_mR17.txt
M1_mR18.txt
M1_mR19.txt
M1_mR2.txt
M1_mR20.txt
M1_mR21.txt
M1_mR22.txt
...
M1_mR89.txt
M1_mR9.txt
M1_mR90.txt
M1_mR91.txt
M1_mR92.txt
M1_mR93.txt
M1_mR94.txt
M1_mR95.txt
M1_mR96.txt
M1_mR97.txt
M1_mR98.txt
M1_mR99.txt

which is unlikely to be very useful for further analysis.

To import the files in order 1,2,3,...100 you will either need to sort the filenames taking into account the number value (e.g. using an alphanumeric sort) or generate the filenames yourself (e.g. using sprintf).