Read text file without header and separate columns

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Philipp Reh 2020-4-29

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编辑： Rik 2022-4-21

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Dear Matlab Team,

my problem is as follows. I could not find a solution in other forums, but none seem to work for my issue:

I have a text file with a big headliner, which I want to skip. The data I need starts in line 194 and has 50.000 values. There are 3 values in each row, sperated by ",". Basically, what I need is to extract the 50 000 values and put it in matrix with 3 columns for further analyzation.

This is how the file looks like (starting from below "DATA BLOCK..."]

...
[DATA BLOCK 1-1-1]
0.00000,20.47668,0.13959
0.00010,20.46021,0.16467
0.00020,20.47668,0.11914
0.00030,20.48767,0.19208
...

How can I separate this data and create a matrix from it?

Thanks in advance,

Philipp

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Rik 2020-4-29

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编辑：Rik 2020-4-29

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You can use the readmatrix function.

A = readmatrix(filename,'NumHeaderLines',193);

Edit:

As Walter suggested below: releases older than R2019a are missing the readmatrix function. On R2013b or newer, the readtable function can help out:

A = table2array(readtable(filename,'NumHeaderLines',193, 'readvariablenames', false));

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Walter Roberson 2020-5-6

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Looks like I misinterpreted what was being requested.

You should be pre-initializing A.

input_folder = 'folder'; 
files = dir(fullfile(input_folder, '*.txt'));
file_paths = fullfile({files.folder}, {files.name});
nfile = numel(file_paths);
for i = 1 : nfile
    data =  readmatrix(file_paths{i},'NumHeaderLines',193);
    if i == 1
      A(:,3*nfile) = 0;     %grow array to largest size
    else
      A(:, i*3-2:i*3) = data;
    end
end

Philipp Reh 2020-5-6

Thank you.

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B 2022-4-21

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编辑：Rik 2022-4-21

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I think summarizing you've got something like this:

input_folder = 'folder'; 
files = dir(fullfile(input_folder, '*.txt'));
file_paths = fullfile({files.folder}, {files.name});
nfile = numel(file_paths);
for i = 1 : nfile
    data=  readmatrix(file_paths{i},'NumHeaderLines',1);% a display of data in a single file
    cols=3*(i-1)+(1:3)
    A(:,cols)=data; % A is your desired result outpout file
end