On Mar 3, 2014, at 7:14 AM, Francisco Lopez de la Franca <[log in to unmask]> wrote: > I've used gp.koza.xover.likelihood to set the probability of performing the crossover operator and I've seen differences in my results, what it sounds good. > After checking the koza.params file, I see that like for xover, there is a gp.koza.mutate param. I've tried with gp.koza.mutate.likelihood and when printing unaccessed params, the gp.koza.mutate.likelihood appears in that list. GP has a different traditional pipeline: no mutation is used. So setting likelihood won't have any effect, since mutation doesn't appear in the pipeline at all. > Please, how do I set a probability for performing the mutation operator, I mean, with probability 0.x I want the mutation operation to be performed? You will need to modify the GP pipeline to include mutation as appropriate. Sean