Question

Can anyone provide some pseudo code for a roulette selection function? How would I implement this:

I don’t really understand how to read this math notation. I never took any probability or statistics.

Answer 1

It’s been a few years since i’ve done this myself, however the following pseudo code was found easily enough on google.

 for all members of population     sum += fitness of this individual end for  for all members of population     probability = sum of probabilities + (fitness / sum)     sum of probabilities += probability end for  loop until new population is full     do this twice         number = Random between 0 and 1         for all members of population             if number > probability but less than next probability                  then you have been selected         end for     end     create offspring end loop 

The site where this came from can be found here if you need further details.