tic
% The program section to time.
toc
Sometimes programs run too fast for tic and toc to provide useful data. If your code is
faster than 1/10 second, consider measuring it running in a loop, and then average to find
the time for a single run.
The cputime Function vs. tic/toc and timeit
It is recommended that you use timeit or tic and toc to measure the performance of
your code. These functions return wall-clock time. Unlike tic and toc,
the timeit function calls your code multiple times, and, therefore, considers first-time
costs.
The cputime function measures the total CPU time and sums across all threads. This
measurement is different from the wall-clock time that timeit or tic/toc return, and
could be misleading. For example:
- The CPU time for the pause function is typically small, but the wall-clock time
accounts for the actual time that MATLAB execution is paused. Therefore, the wall-
clock time might be longer. - If your function uses four processing cores equally, the CPU time could be
approximately four times higher than the wall-clock time.
Tips for Measuring Performance
Consider the following tips when you are measuring the performance of your code:
- Time a significant enough portion of code. Ideally, the code you are timing should take
more than 1/10 second to run. - Put the code you are trying to time into a function instead of timing it at the command
line or inside a script. - Unless you are trying to measure first-time cost, run your code multiple times. Use the
timeit function. - Avoid clear all when measuring performance. For more information, see the clear
function. - Assign your output to a variable instead of letting it default to ans.
Measure Performance of Your Program