Can anyone tell me where I went wrong below that I get Invalid file identifier error? This code attempts to write data in different output files, where file name includes a number and strings.

ST = 14;
NR = 2
for r = 1:NR
file = fopen(['LadPos' int2str(ST+r) '.txt','w']);
fprintf([file,'Competition Ladder for Round' char(ST+r)]);
for i = 1:NT
fprintf(file,'%d %s %d\n',i,Classiclad(i,:),classic(i));
end
fclose(file);
....

Answer 1

[Orion]

You wrote

fprintf([file,'Competition Ladder for Round' char(ST+r)])

the [ ] are misplaced, it should be :

fprintf(file,['Competition Ladder for Round' char(ST+r)])

[Ellie]

It did not work, I get the same error!

Answer 2

[Image Analyst]

Try this:

ST = 14;
NR = 2
NT = 3
for r = 1:NR
  baseFileName = sprintf('LadPos%d.txt', ST+r);
  fullFileName = fullfile(pwd, baseFileName)
  fileID = fopen(fullFileName, 'wt');
  fprintf('Competition Ladder for Round %d', (ST+r));
  fprintf(fileID, 'Competition Ladder for Round %d' (ST+r));
  for i = 1 : NT
    fprintf(1,'%d %s %d\n',i,Classiclad(i,:),classic(i));
    fprintf(fileID,'%d %s %d\n',i,Classiclad(i,:),classic(i));
  end
  fclose(fileID);
end

[Ellie]

Thanks Mate. It worked.

[Image Analyst]

You're welcome. Can you officially mark it as "Accepted" then? Thanks.