Multiple text file read i Matlab

I want matlab to read multiple text file. The matlab code to read the single text file and specific line is attached. How to read multiple text from the folder?

fid=fopen('E:\ReliabilityAll\alpha\sub1.txt');

StartLine=3;

for k=1:StartLine-1
  fgetl(fid); % read and dump
end
Fline=fgetl(fid); % this is the 3rd line
%do stuff
fclose(fid)

Answer 1

[madhan ravi]

 for l = 1:8
  fid=fopen(sprintf('E:\\ReliabilityAll\\alpha\\sub%d.txt',l));
 StartLine=3;
 for k=1:StartLine-1
     fgetl(fid); % read and dump
 end
 Fline=fgetl(fid); % this is the 3rd line
 %do stuff
 fclose(fid)
 end

[Khan Muhammad Adeel Khan]

Thanks for the reply. But this will generate the following errors as:

Warning: Escaped character '\R' is not valid. See 'doc sprintf' for supported special characters.

> In linetext (line 3)

Error using fgets

Invalid file identifier. Use fopen to generate a valid file identifier.

Error in fgetl (line 32)

[tline,lt] = fgets(fid);

Error in linetext (line 6)

fgetl(fid); % read and dump

[madhan ravi]

Replace \ with \\

[Khan Muhammad Adeel Khan]

It works but can output the value of subject 8 only. I want to save the result from subject 1 to 8. Thanks for the response.

for l = 1:8
  fid=fopen(sprintf('E:\\ReliabilityAll\\alpha\\sub%d.txt',l));
  all_results=[];
 StartLine=3;
 for k=1:StartLine-1
     fgetl(fid); % read and dump
 end
 Fline=fgetl(fid); % this is the 3rd line

 all_results1=Fline;
 all_results=[all_results;all_results1];
  %do stuff
  fclose(fid)
 end

[Walter Roberson]

I suggest

base = 'E:\ReliabilityAll\alpha\sub';

for l = 1 : 8
    filename = sprintf('%s%d.txt', base, l);
    [fid, msg] = fopen(filename);
    if fid < 0
        error('Failed to open file "%s" because "%s"', filename, msg);
    end
end

[madhan ravi]

 Fline = cell(8, 1);
 for l = 1:8
   fid=fopen(sprintf('E:\\ReliabilityAll\\alpha\\sub%d.txt',l));
  StartLine=3;
  for k=1:StartLine-1
      fgetl(fid); % read and dump
  end
  Fline{l} = fgetl(fid);  % this is the 3rd line
  %do stuff
  fclose(fid)
  end
 celldisp(Fline)

[Khan Muhammad Adeel Khan]

Thanks @Madhan Ravi It really works and save my time to do it manually. I am pleased to note that it is really a very active platform and grateful to all of you for the kind response

[madhan ravi]

I suggest you to read sir Walter’s comment as well.

[Khan Muhammad Adeel Khan]

Thanks Sir for the feedback and answers from you both really save my time and energy @Walter Roberson. Could you please suggest me a good platform to learn the coding in Matlab in an effective way or suggest any online open source? I woud be grateful

Answer 2

[Robert]

You might also use a direct loop on the result of using the 'dir' command, if the '*' placeholder is sufficient for your search. Take care to use the transpose operator ' on the result of dir, because you need a row vector of results to for-loop.

sDir = 'C:\Users\Khan\Documents\MATLAB';
for sctFile = dir(fullfile(sDir, 'sub*.txt'))'
    fh = fopen(fullfile(sDir, sctFile.name));
    % here goes your code
    % ...
    fclose(fh);
end

Or just dir on the directory, and filter the file names within the loop..