MATLAB: Strange results from tic / toc.

run timetic toc

I'm checking the running time of a function using tic/toc. I write the following in the command window (and execute it simultaneously):
tic
res = checkFunc('case2736sp',1:3000);
toc
Elapsed time is 0.080491 seconds.
where checkFunc returns a 2736×2500 full matrix.
What puzzles me is that I have to wait almost 20 seconds for the output saying the run time is only 80 ms.
Does anyone have a clue why this is?

Best Answer

Are you sure 'checkFunc' does NOT do a tic somewhere in its code? Anyways, this would be a better way to test:
tx = tic; res = checkFunc('case2736sp',1:3000); toc(tx)