How to identify an iteration that throws a warning/error?

I have a for-loop and some iterations are throwing warnings. I would like to know which iterations are the ones throwing the warning. Here is what I have tried:

errclass = zeros(1,nODF);
lastwarn(''); % reset warning state
for i = 1:nODF

      DO STUFF (including computing eigenvalues of a matrix)

      % check for error
      [warnmsg, msgid] = lastwarn;
      if ~strcmp(msgid,'')
          errclass(i) = 1;
      end
      lastwarn(''); % reset warning state

end

However, when I evaluate sum(errclass) I get that only 8 warnings were thrown. As you can see in the attached document, which is what I see in the command window, there are far more than 8 warnings thrown, so this is somehow missing many of the warnings. Any suggestions?

Answer 1

[Image Analyst]

Try

dbstop if warning

or else just step through a line at a time until the warning gets printed in the command window.

[Oliver Johnson]

I want the entire loop (nODF is quite large) to run and then be able to do the analysis after (I plan to exclude the data corresponding to the iterations that threw warnings). So dbstop doesn't seem to help here, since it will require user interaction, right?

[Image Analyst]

If you want to turn off warnings, read the comments in the attached file and see how I do it for some warnings I want to suppress. The comments will tell you how to suppress the warning.

Answer 2

[Walter Roberson]

"DO STUFF" might be throwing multiple warnings for the same iteration. That would make the number of emitted warnings larger than the number of iterations for which warnings were counted.