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On May 5, 2007, at 12:36 AM, Matthew Walker wrote: > I'm *very* new to ECJ, so my apologies if I have done something > stupid. I would, however, very much appreciate someone telling me > where I've gone wrong! > > I have run the parity examples provided with ECJ and I'm confused > with the results. I have tried to reproduce some of the > experiments in Koza's second book. My expectation was that I could > use the parity examples provided with ECJ to get similar results to > chapter 6 of GPII which generally concludes that the use of ADFs is > a good thing for this domain. > > ... > > So, to summarize, Standard GP scored 32.4% while GP with ADFs > scored 0.6%. From Koza's second book on GP (page 181), this was > not what I expected to get. I expected GP with ADFs to outperform > standard GP on this problem domain. I sat around scratching my > head trying to work out what I had done wrong, however nothing but > hair came out ;o) Hi Matt. This is the first time that this bug [if it is one] has been reported and no, you're not necessarily doing something stupid. I'm not sure what the problem is, but there are several possibilities: - A bug in the ADF code (possible) - A bug in the parity problem example (less likely but possible) - Errors in Koza's text There have been some significant errors in Koza's text on certain problem domains, so it's a definite possibility. What we need is a third implementation to verify if it's ECJ doing this or not. lil-gp anyone? Or maybe open beagle? As to memory: 16,000 is a big number for ECJ, which is fairly memory hungry. What -Xmx and -Xms settings did you set on your VM, however? Sean