Here is a minimal working example to illustrate what I am trying to ask:
function test(n::Int)
tic()
i = 0
while (i <= n)
A = randn(100,100)
B = randn(100,100)
C = A*B
i+=1
end
toc()
end
test(100)
I always time my functions by putting @time in front of the function call (like @time test(100)). However, I realized that if I put tic() and toc() inside the function definition, then the timing result could be quite different.
For the example above, I get elapsed time: 0.033487528 seconds. However, if I remove the tic() and toc() and use
tic()
test(100)
toc()
then I get elapsed time: 0.047568188 seconds. (In both case, the code is run at least twice to avoid the compilation time.)
I don’t really understand what influences the gap between the two ways of timing. I am asking this because in my actual project, I encounter a timing difference of about 0.66 second and 0.015 second, which is quite significant! What are the common reasons for making this gap large? Thanks!
