I believe this issue comes from predetermined tree depth that is trying to be filled out. A workaround in the mean time is to add a pass through primitive:

def pass_through(x):
    return x

pset.addPrimitive(pass_through, [int], int, name='pass_int')

I believe this issue comes from predetermined tree depth that is trying to be filled out. A workaround in the mean time is to add a pass through primitive:

def pass_through(x):
    return x

pset.addPrimitive(pass_through, [int], int, name='pass_int')

Thank you for reply, I used the method to avoid the problem, but this led the expressions to be redundant, and not graceful.

Yes but logically it does not make sense to ask the program to build full trees if for some non-leave it is impossible to find an other non-leave if the required type. I guess there could be a tree generation utility that allows for it ...

I believe this issue comes from predetermined tree depth that is trying to be filled out. A workaround in the mean time is to add a pass through primitive:

def pass_through(x):
    return x

pset.addPrimitive(pass_through, [int], int, name='pass_int')

Thank you for reply, I used the method to avoid the problem, but this led the expressions to be redundant, and not graceful.

Hi @liningbo, have you figured out how to avoid this problem?

I believe this issue comes from predetermined tree depth that is trying to be filled out. A workaround in the mean time is to add a pass through primitive:

def pass_through(x):
    return x

pset.addPrimitive(pass_through, [int], int, name='pass_int')

Thank you for reply, I used the method to avoid the problem, but this led the expressions to be redundant, and not graceful.

Hi @liningbo, have you figured out how to avoid this problem?

@BrandonDotLin I just do as jasonzutty said, make a function to return a int value equal to the input of the function.

    while len(stack) != 0:
        depth, type_ = stack.pop()
        if condition(height, depth) or len(pset.primitives[type_]) == 0:
            try:
                term = random.choice(pset.terminals[type_])
            except IndexError:
                _, _, traceback = sys.exc_info()
                raise IndexError("The gp.generate function tried to add "
                                 "a terminal of type '%s', but there is "
                                 "none available." % (type_,)).with_traceback(traceback)
            if isclass(term):
                term = term()
            expr.append(term)

you can add some code to generate in gp.py

Hope this pull request can be merged ASAP.

This cannot be merged as it breaks the logic of a full tree.