Print

Print


Thanks, this is what I was looking for.

David

Keith Sullivan wrote:
> yes, there is an upper limit: a depth of 17.  It depends on how you 
> are doing breeding.  Under the gp directory, look in the parameter 
> files for parameters that have maxdepth.  This parameters controls how 
> depth the newly bred trees can be.  Also, look for parameters with 
> same containing max-depth, which controls how large the initial trees 
> are.
>
> Keith
>
>
>
>
> On Jul 24, 2008, at 5:15 PM, David R White wrote:
>
>> Hi,
>>
>> Thanks for the reply Shane.  The below is for the initialisation of 
>> the population, but I'm actually concerned about how large the trees 
>> can become within the run itself.  Is there some upper limit?  Sorry, 
>> I don't think I phrased my question very well!
>>
>> Cheers
>>
>> David
>>
>> Shane wrote:
>>> Take a look at this in koza.params:
>>>
>>> # The tree uses an ec.gp.koza.HalfBuilder to create
>>> # itself initially.
>>> # HalfBuilder will pick GROW half the time and FULL
>>> # the other half, with a ramp from 2 to 6 inclusive.
>>> # By ramp we mean that it first picks a random number between
>>> # 2 and 6 inclusive.  This then becomes the *maximum* tree size
>>> # (for the FULL approach, it's the tree size of the tree, for
>>> # GROW, the tree can get no bigger than this)
>>>
>>> gp.tc.0.init = ec.gp.koza.HalfBuilder
>>>
>>> # We set the default for HalfBuilder to be a ramp of 2--6,
>>> # with a grow probability of 0.5
>>> gp.koza.half.min-depth = 2
>>> gp.koza.half.max-depth = 6
>>> gp.koza.half.growp = 0.5
>>>
>>>
>>>
>>> On Thu, Jul 24, 2008 at 12:08 PM, David Robert White 
>>> <[log in to unmask] <mailto:[log in to unmask]>> wrote:
>>>
>>>     Hi,
>>>
>>>     Please could someone help me with this query:
>>>
>>>     Is there a limit on the tree sizes that ECJ can create?  Is there
>>>     any restriction on tree size that I should know about?  I'm asking
>>>     because I am experiencing bloat in a run up to a point, and no
>>>     further increase in size after that point.  Perhaps some internal
>>>     limit has been reached?
>>>
>>>     Thanks,
>>>
>>>     David
>>>
>>>     --     David R White
>>>
>>>     Research Student
>>>     Department of Computer Science
>>>     University of York
>>>     York YO10 5DD
>>>     United Kingdom
>>>
>>>
>>
>> -- 
>> David R White
>>
>> Research Student
>> Department of Computer Science
>> University of York
>> York YO10 5DD
>> United Kingdom
>>
>> Phone: +44 (0)1904 434756

-- 
David R White

Research Student
Department of Computer Science
University of York
York YO10 5DD
United Kingdom