Absolutely, in fact they work exactly the same. ECJ's GE system evaluates individuals by building a *GP* tree out of them, then evaluating the GP tree with ECJ's GP facility. So tree evaluation generally works the same between the two. Sean On Mar 1, 2016, at 12:43 AM, bijoy patwal <[log in to unmask]> wrote: > Hi, > Can I extend GPData class in same way while doing Grammatical Evolution as I can in ec.gp package. > Is there any example in ecj that does it. > > Thanks in advance.