Merge files with the same prefix.

I have multiple .txt files. From these files have the same three letters in their name. I want to create a new file that will contain the data of all the files that have the first three letters in their name (e.g. "ABC****P.txt, ABC****T.txt, BCA****P.txt, BCA****T.txt". I want to megre in one file the first two .txt and one file the last two .txt files)

could you help me please?

Answer 1

[Stephen23]

This should get you started (untested, but gives an outline of how you could do this):

D = 'path to the folder where the files are saved';
S = dir(fullfile(D,'*.txt'));
C = {S.name};
T = regexp(C,'^.{3}','once','match');
U = unique(upper(T));
for k1 = 1:numel(U)
    X = find(strncmpi(C,U{k1},3));
    N = numel(X);
    A = cell(1,N);
    for k2 = 1:N
        F = fullfile(D,C{X(k2)});
        A{k2} = ...whatever file importing that suits your file format.
    end
    M = vertcat(A{:});
    F = sprintf('%s merged.txt',U{k1});
    ... save matrix M with filename F using whatever file exporting that suits your data
end

[Ivan Mich]

Thank you.

Excuse me but I do not understand line:

A{k2} = ...whatever file importing that suits your file format.

What do you mean?

[Rik]

You need to read the file to a format that is suitable for your use.

[Ivan Mich]

Excuse me but I am really confused. Could you give me an example of what you mean?

What should I write?

[Stephen23]

"What should I write?"

I don't know, because you did not give any information on the file format.

Different file formats can be imported by different functions. You need to either:

1. select a function that suits your file format, or
2. upload a sample file so that someone here can help you to select an appropriate function.

[Ivan Mich]

One file of these I have mention is the file I am importing. I import this in order to understand what do you mean.

All my files have this format

[Stephen23]

@Ivan Mich: Which of these do you want:

1. keep only the numeric data, discarding the headers.
2. retain the header from the first file.
3. retain the header from each file.
4. something else...

If your answer is 1, then you can use dlmread to import the file, e.g.:

A{k2} =  dlmread(F,'',5,0);

and then dlmwrite to export the data at the end.

[Rik]

How do you want to merge them? Do files with the same starting letters have the same date? Should the header be repeated? What does 'merging' mean for your specific data format?

[Ivan Mich]

I would like to merge them horizontally (I mean I want to have 4 columns, which the firts two are from the one file and the last two are from the second file). I do not want to have the headers.

[Rik]

Have you read the documentation for every function you didn't understand in the answer?

Let me give you a short-cut: read the documentation for sprintf.