A script to append a column with values and read multiple txt files from different folders

I have 6 folders, in each folder there is a text file with three columns omega, G' and G" with values. Want to add a new column viscosity with values and also read all the text files in just one code from different folders

a=readtable('Pure_melt.txt');

a1=a(:,1);

a1=table2array(a1);

b=a(:,2);

b=table2array(b);

g1=b.^2;

c=a(:,3);

c=table2array(c);

g2=c.^2;

v=sqrt(g1+g2)./a1;

f=[a1'; b'; c'; v'];

file_ID=fopen('Pure_melt.txt','w');

t=' omega gp gdp vis';

fprintf(file_ID,sprintf('%s %s %s %s\n',t));

fprintf(file_ID,'\n %3f %3f %3f %3f \n',f);

fclose(file_ID);

This is just one code where i run the code for just one text file

want to run all the 6 text file in just one code

Thanks in advance

[Rik]

What did you try so far to make this code independent of the file name? Once you do that, you can trivially reuse your code.

[SS]

K

Answer 1

[Kautuk Raj]

This is an example MATLAB code that should accomplish what you described:

% Define the names of the folders containing the text files
folder_names = {'folder1', 'folder2', 'folder3', 'folder4', 'folder5', 'folder6'};
% Initialize empty arrays to store the data
omega_all = [];
Gprime_all = [];
Gdoubleprime_all = [];
viscosity_all = [];
% Loop over the folders
for i = 1:length(folder_names)
    % Get the name of the folder
    folder_name = folder_names{i};
    
    % Get the names of all the text files in the folder
    file_names = dir(fullfile(folder_name, '*.txt'));
    
    % Loop over the text files
    for j = 1:length(file_names)
        % Get the name of the text file
        file_name = fullfile(folder_name, file_names(j).name);
        
        % Load the data from the text file
        data = load(file_name);
        
        % Extract the columns of interest
        omega = data(:, 1);
        Gprime = data(:, 2);
        Gdoubleprime = data(:, 3);
        
        % Calculate the viscosity
        viscosity = Gdoubleprime ./ omega;   
        
        % Append the data to the arrays
        omega_all = [omega_all; omega];
        Gprime_all = [Gprime_all; Gprime];
        Gdoubleprime_all = [Gdoubleprime_all; Gdoubleprime];
        viscosity_all = [viscosity_all; viscosity];
    end
end
% Combine the data into a single matrix
data_all = [omega_all, Gprime_all, Gdoubleprime_all, viscosity_all];
% Save the data to a file
save('all_data.mat', 'data_all');

This code assumes that the text files have the same format in all folders, with three columns of data separated by whitespace. If the format is different, you may need to modify the code to read the data correctly.

The code loads the data from each text file, calculates the viscosity, and appends the data to arrays. Then it combines the arrays into a single matrix and saves the matrix to a file.