Break loop after designated length of time in Matlab

Question

I'm a bit confused by the tic function, but I'm not sure if there's something better for what I'm trying to do. In psuedo-Matlab:

startTime = tic

while(true)

   #some_stochastic_process

   if(now - startTime > RUNTIME)
     break;
   end
end

But subsequent calls to tic will clobber the original time. Is there a way to access the current value of tic without overwriting it?

Answer 1

The function NOW returns a serial date number (i.e. an encoded date and time). You should instead be pairing the call to TIC with a call to TOC to perform stopwatch-like timing, like so:

timerID = tic;  %# Start a clock and return the timer ID

while true

    %# Perform some process

    if(toc(timerID) > RUNTIME)  %# Get the elapsed time for the timer
        break;
    end

end

Alternatively, you could simplify your loop like so:

while (toc(timerID) < RUNTIME)

    %# Perform some process

end