Comments on: Timing code in MATLAB http://blogs.mathworks.com/videos/2008/02/12/timing-code-in-matlab/ Doug Hull is a proud MathWorker who is on a mission to help you with MATLAB. Mon, 06 Feb 2012 18:06:13 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Doug http://blogs.mathworks.com/videos/2008/02/12/timing-code-in-matlab/#comment-821 Doug Fri, 15 Feb 2008 13:42:03 +0000 http://blogs.mathworks.com/videos/2008/02/12/timing-code-in-matlab/#comment-821 Tim, an excellent suggestion. I would want to make sure that the time for dosomething >> the rest of the code in loop. For most applications it would be. Thanks, Doug Tim, an excellent suggestion. I would want to make sure that the time for dosomething >> the rest of the code in loop. For most applications it would be.

Thanks,
Doug

]]> By: Tim Davis http://blogs.mathworks.com/videos/2008/02/12/timing-code-in-matlab/#comment-820 Tim Davis Fri, 15 Feb 2008 12:16:55 +0000 http://blogs.mathworks.com/videos/2008/02/12/timing-code-in-matlab/#comment-820 Sometimes you want to time code that runs for a teeny fraction of a second, and tic ; dosomething ; t = toc is not accurate. The profiler will also be inaccurate. (You might want to time this teeny fraction of a second becaus you want to use the dosomething function zillions of times inside a larger application). Here is a trick I like to use tic ; t = 0 ; ntrials = 0 ; while (t < 1) dosomething ; ntrials = ntrials + 1 ; t = toc ; end t = t / ntrials ; That way, you run "dosomething" enough times to accumulate a whole second, and then you compute the average time per call to dosomething. Sometimes you want to time code that runs for a teeny fraction of a second, and

tic ;
dosomething ;
t = toc

is not accurate. The profiler will also be inaccurate. (You might want to time this teeny fraction of a second becaus you want to use the dosomething function zillions of times inside a larger application). Here is a trick I like to use

tic ;
t = 0 ;
ntrials = 0 ;
while (t < 1)
dosomething ;
ntrials = ntrials + 1 ;
t = toc ;
end
t = t / ntrials ;

That way, you run “dosomething” enough times to accumulate a whole second, and then you compute the average time per call to dosomething.

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