toc - Stop clock to measure performance

Syntax

Description

toc stops a stopwatch timer started by the tic function, and displays the time elapsed in seconds.

toc(ticID) displays the time elapsed since the tic command corresponding to ticID.

elapsedTime = toc stores the elapsed time in a variable.

elapsedTime = toc(ticID) stores in a variable the time elapsed since the tic command corresponding to ticID.

Tips

• Consecutive toc commands return the increasing time that has elapsed since the most recent tic. Therefore, you can take multiple measurements from a single point in time.

• The toc function displays the time elapsed unless you specify an output argument.

Input Arguments

ticID

Identifier generated by a previous call to tic with an output argument.

Output Arguments

elapsedTime

Scalar double representing the time elapsed between tic and toc commands, in seconds.

Examples

Measure how the time required to solve a linear system varies with the order of a matrix:

t = zeros(1,100);
for n = 1:100
    A = rand(n,n);
    b = rand(n,1);
    tic
    x = A\b;
    t(n) = toc;
end
plot(t)

Measure the minimum and average time to compute a summation of Bessel functions:

REPS = 1000;   minTime = Inf;   nsum = 10;
tic;

for i=1:REPS
   tStart = tic;   total = 0;
   for j=1:nsum, 
      total = total + besselj(j,REPS);
   end

   tElapsed = toc(tStart);
   minTime = min(tElapsed, minTime);
end
averageTime = toc/REPS;

See Also

clock | cputime | etime | profile | tic

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