Faster computation time in for loop

Hi all!

I am working on a project and I have run into something which I am wondering about. I have this function which assigns waiting times (random numbers from a distribution depending on a "temperature") to two arrays called WaitingTimes. I have tried to time the operation the following way:

tic
WaitingTimes(ones(1,30),ones(1,69),10);
toc

and usually the result is about 0.015, maybe 0.008 on a good run. The funny thing is that if I am instead timing it like this:

for t=1:100  
tic  
WaitingTimes(ones(1,30),ones(1,69),10);
toc
end

 then the time is about 0.002 and 0.0065 is the highest value. Does anyone know why, and maybe if it is possible to optimize something to make my function only take 0.002 most of the time instead of 0.015?

Thanks in advance, Mads

[James Tursa]

This times involved are small enough that tic toc around a single call might not reveal much. What does this show?

tic
for t=1:100  
    WaitingTimes(ones(1,30),ones(1,69),10);
end
toc

[Navaneeth Raman]

Hi,

The small difference in time shown by tic toc is expected. You machine is running a lot of other applications in the background in addition to MATLAB. This is one of the very many reasons on what is causing the time difference each time you run your function.

HTH, Navaneeth