On 07/08/2012 08:39 PM, Burton Samograd wrote:
That was the problem. I'm running a simulation with hundreds of thousands of agents and that blue moon shows up pretty frequently. I tried your idea of subtracting from 1 on CCL (SBCL is being too finicky right now) and it doesn't seem to follow the standard of [0.0...1.0). I ended up just adding 1E-32 to (random 1.0); I really don't think it will make a difference (famous last words).
It might be very small numbers will kill log also. If that's the case, 
then you could figure out the threshold for smallest argument to log, 
and put some logic in there to exclude those cases (regen another 
uniform variate).
Maybe but since my tiny addition I haven't had the problem so I'm 
satisfied with it as a solution for now.
Jeff Cunningham

--
Burton Samograd


Careful that U+epsilon doesn't exceed 1.0 or you will mess up the distribution where it counts. It probably would be better to throw away U's that are less than epsilon. All your doing then is cutting off the tails way out there somewhere.

Jeff Cunningham