 |
 |
There is always the definite possibility of a bug in ECJ: for example, I just routed out a long-standing one in Lawnmower recently (check CVS). But another reason may be that Koza-I and Koza-II'ss results have proven historically difficult to reproduce. There are a number of reasons for this, but here are two: the random number generator used in Koza-I and Koza-II was troublingly non-random; and certain variables are not as you'd expect in print. For example, though Koza- I says 400 timesteps for Artificial Ant, in fact it's believed he used 600. So much subsequenty work used 400 timesteps as a result that that's the default for both ECJ and lil-gp. You an change it to 600 and see what's up. There are other explanations for differences which have been offered which I don't want to get into here. So: if we can nail down a bug, I'd love to find out. But be prepared for the probability that it's Koza-I and not ECJ. One way to check for the possibility of an ECJ bug in certain problems is to run lil-gp and see which one it more or less agrees with. Let me know what you get. Sean On Oct 27, 2009, at 5:37 PM, David F. Barrero wrote: > Dear all, > > I am trying to reproduce Koza's performance curves for some typical GP > problems implemented in ECJ, but I had a limited success. Some > problems > such as simple regression have similar performance curves compared > with > the ones shown in Koza I, while others (for instance, Santa Fe trail > or > even 5 parity with ADFs) yields very different curves. > > In theory, should ECJ examples generate the same performance curves > than > those shown in Koza I/II?. > > > Thanks in advance, > > David > > > > > -- > David F. Barrero > Departamento de Automática > Universidad de Alcalá > > Tlf: (34) 91-885-69-20 > Web : http://atc1.aut.uah.es/~david/ > Jabber/GTalk: [log in to unmask] > Skype: dfbarrero > > Escuela Politécnica > Departamento de Automática > Despacho E-236 > Ctra. Madrid-Barcelona km 31,600 > 28871 Alcalá de Henares. Madrid > -- >