`tic`

Starts a stopwatch timer.

Category: Software Development Tools > Performance and Memory

Syntax

tic

Starts the timer. A later call to toc reports the time since this point.

t = tic

Starts the timer and returns an id that identifies this stopwatch.

Description

tic records the current moment and toc reads the elapsed wall-clock seconds from it. Without an output, tic stores the moment in a single shared timer, and each new tic replaces it.

The pair is meant for coarse timing of a block of code. For a reliable measurement of a fast function, timeit repeats the call and removes overhead.

Output arguments

t: Timer id, to be passed to toc(t) when several stopwatches run at the same time.

Example

Timing a loop

tic
s = 0;
for k = 1:1e5
    s = s + sqrt(k);
end
t = toc;
disp(t >= 0)
fprintf('%.2f\n', s)

Output

   1
21082008.97

tic