MATLAB: Read and format multiple text files line by line

Question

Hi all,

I have about 50 text files. Each text file has 17 columns and several rows of data(attached a sample file).

Now I have to extract data from one file, plot and save a figure from the data, and close the file. I have to repeat this for all the text files. I have tried writing the following code to first open file, extract data and close file,

tfiles = dir('*.txt');
    ntfiles = length(tfiles);
    for i = 1 : ntfiles
       fid = fopen(tfiles(i).name);
       D = textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f');
       fclose(fid);
    end

But my code displays only blank values. So how to extract all the lines?

Also I would like to know how to proceed with these issues,

1. I know how to remove the first 8 header lines. But the header seems to be repeated throughout the text. So is there any way I could look for a particular string and delete the entire row from that?

2. Also I need to delete rows which does not contain values in all the 17 columns or contains value in more than 17 columns. How can I check this condition?

Any help would be very useful.

Answer 1

Try this

fid = fopen('sample.txt', 'r');
data_array = {};
while ~feof(fid)
    data = cell2mat(textscan(fid, repmat('%f ', 1, 17)));
    if isempty(data)
        fgetl(fid);
    else
        data_array{end+1} = data;
    end
end
data_array = cell2mat(data_array');
mask = data_array(:,1) == 1;
data_array(~mask, :) = []; % only rows with first element 1 are part of actual dataset

You can extend it to multiple files in for loop.