How to create a log file?

Dear Matlab expert, Anyone of you know how to create a log file?

Your sincerely, Kelly

Answer 1

[Jan]

It depends on what you consider a "log file" to be.

It is easy to append any messages to a file:

yourMsg = 'I am alive.'
fid = fopen(fullfile(tempdir, 'YourLogFile.txt'), 'a');
if fid == -1
  error('Cannot open log file.');
end
fprintf(fid, '%s: %s\n', datestr(now, 0), yourMsg);
fclose(fid);

Copy this into a function and you can use it from where ever you want.

Or perhaops you mean the diary function? See:

doc diary

[Kelly Wong]

Hi thanks for fast reply, i want to do something like this http://www.blackbeltcoder.com/Articles/files/a-convenient-logfile-class/LogFileSample.jpg. Is it possible to do in matlab?

Cheers, Kelly

[Liz Martinez Marrero]

Hi, The code works for the first log, but then it overwrites the previous logs. Any suggestion? Thanks

[David Connell]

Liz, are you using the 'a' option with fopen?

fid=fopen(filename, 'w')

will write over the old file but

fid=fopen(filename, 'a')

will append the new data to the end of the file.

If that's not the problem could you show your relevant code?