Inconsistent tic and toc

I see a smooth frame rate, but when I measure the frame rate with tic and toc I frequently see unrealistic measurements, like less than one frame per second. I would definitely notice such a frame drop. Below is an extreme example measuring the time for one frame to 16 seconds, but I never saw any stutter.

Can someone help me to ever trust tic toc again, please.

Excerpt from code (simplified)

    tic
    while j < 1000 && ~quit
      aaa = toc;
      disp(['Frame rate = ' num2str(1 / aaa)])
      if 1 / aaa < 1
        disp(aaa)
        toc
      end
      tic
      pause(.001)
      j = j + 1;
      PlotStuff(j)
    if strcmp(KEY_EVENT.Key, 'q') % I use a WindowsKeyPress callback.
      quit = 1;
      end
    end

Excerpt from output

    Frame rate = 40.9828
    Frame rate = 44.1438
    Frame rate = 41.395
    Frame rate = 30.4108
    Frame rate = 29.6011
    Frame rate = 40.0793
    Frame rate = 32.4089
    Frame rate = 42.4079
    Frame rate = 0.061352
       16.2994

    Elapsed time is 16.299732 seconds.
    Frame rate = 39.5448
    Frame rate = 32.8217
    Frame rate = 32.0156
    Frame rate = 41.5176

Answer 1

[Matt J]

Maybe do

PlotStuff(j); drawnow