Talk:Gene expression programming

message: Can anyone give a good comparison between Gene Expression Programming (GEP) and Linear Genetic Programming (LGP)? According to this article, it seems that the only difference between GEP and Genetic Programming (of which LGP is a subset) is how programs, in the population to evolve, are represented. Quoting the relevant fragment:
"In Genetic Programming the individuals comprising a population are typically symbolic expression trees; however, the individuals comprising a population of GEP are encoded as linear chromosomes, which are then translated into expression trees. That is, in GEP, the genotype (the linear chromosomes) and the phenotype (the expression trees) have a different encoding structure."
Emphasis mine. Now, "typically" does not exclude other representations, indeed LGP is a counter-example. In LGP each program from the population is represented as a sequence of instructions, sometimes directly as machine instructions as in the approach of Peter Nordin, which doesn't need a translation phase "from genotype to phenotype", to use GEP questionable terminology (IMO the author doesn't understand the difference between a process - a running program - and its specification - a program properly encoded; using GEP analogy, a program is always genotype). I concur with section "Dubious claims throughout" below, where the merits of such translation in GEP is questioned.
--MaD70 (talk) 15:27, 24 January 2010 (UTC)
replies: text: The difference is the way that the programs are represented during the reproduction stage.  In GEP this allows the use of genetic algorithm methodologies while in the genotype form and defines a upper limit to program size.  Genotype representation is used to simplify the crossover and mutation process by using short strings represent the allowed operators and operands.  Both GEP and LGP are sub-sets of Genetic Programming that use different approaches to achieve the GP goal.  I do think the article needs to be re-written with the GEP algorithm clearly explained. Bob0the0mighty (talk) 14:51, 19 February 2010 (UTC)
replies: text:  LGP is much more well-thought-out, as recombination operating on its linear encoding *actually makes sense*, as opposed to GEP, which might as well be replacing portions of the resulting subtree with random subtrees. LGP's phenotype is comparable to an L-System, describing a *depth-first* constructive process, whereas GEP's is breadth-first, which is patently absurd. I was very disturbed when I found this article had been published in Complex Systems, as it's clearly a crock. 74.64.96.71 (talk) 07:52, 14 October 2010 (UTC)

text:  Also, the usual complaint is that GEP is a subset of "grammatical evolution" (GE). 74.64.96.71 (talk) 22:11, 14 October 2010 (UTC)
thread_title: GEP vs Linear Genetic Programming (LGP)

message: NPOV? "... this new algorithm surpasses the old GP system in 100-10,000 times."  Please specify "old GP system". I think, that Machine code [Linear genetic programming] is really fast. --Michal Jurosz 11:40, 2 November 2005 (UTC)
replies: text: Please sign your posts. Just append four tilde's (~) and the wiki will automatically add your IP address or username (if you have one) and the date. Thanks. 65.183.135.231 (talk) 17:42, 31 October 2008 (UTC)
replies: text:  I simply removed the numeric portion of this claim, replacing it with "significantly".  —Preceding unsigned comment added by 74.64.96.71 (talk) 07:53, 14 October 2010 (UTC)
thread_title: POV

message: "This new algorithm surpasses the old GP system in 100-10,000 times."  What does this mean?  Is it 100-10,000 times faster?  As it stands, this seems a completely nonsensical statement...  —Preceding unsigned comment added by 65.183.135.166 (talk) 08:03, 28 November 2007 (UTC)
thread_title:  What does this mean??? 

message: While roboticists often use evolutionary algorithms in their work, I'm not sure it's really appropriate for this article to be part of Wikiproject Robotics (for example, electrical engineers use EA's as well, but this isn't part of some EE Wikiproject)--I'm sure there is a more appropriate category. How do we change it? Or do folks disagree? 65.183.135.231 (talk) 17:47, 31 October 2008 (UTC)
thread_title:  Wikiproject Robotics 

message: 1. Apparently, in addition to a great number of other researchers, John Koza himself, the inventor of genetic programming, *supposedly* (a less indirect source is wanted for such a claim--EDIT: see #8, below) took the time to speak out against this nonsense:  74.64.96.71 (talk) 09:19, 14 October 2010 (UTC)
thread_title:  Critical responses from researchers 

message: See figure 6, on page 12, of Dr. Ferreira's tutorial: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.128.4476&rep=rep1&type=pdf
This is for a simple quadratic regression problem. Notice how:
  1. There is no discernable trend in the average fitness.
  2. The fitness of the best individual is almost perfect, right from the start.
  3. The accompanying analysis somehow sees this as an excellent result.
Similarly, in figure 13, on page 19, for a more complex regression problem, there is again no discernable trend in the average fitness--even after 5,000 generations!
74.101.91.229 (talk) 06:04, 1 December 2010 (UTC)
thread_title:  Tutorial 

message: Here is a paper, also published in Complex Systems, comparing GEP and 3 other algorithms on a set of 5 benchmark problems: http://www.complex-systems.com/pdf/14-4-1.pdf
Note in particular the graphs and tables in Section 8, where GEP consistently and quite markedly underperforms in comparison to LGP and MEP, often exhibiting nearly flat fitness curves. 74.101.91.229 (talk) 06:19, 1 December 2010 (UTC)
thread_title:  Review paper 

message: I just did a bunch of corrections per WP:MOS and WP:MOSMATH.  In particular, notice that:
* Ranges of pages, years, etc. should have an en-dash, not a hyphen, thus:
:: wrong: pages 31-60
:: right: pages 31–60
: (There were probably a couple of dozen instances of hyphens for this purpose in the article.)
* A minus sign looks different from a hyphen.
:: wrong: 5 - 3
:: right: 5 − 3
: (Of course in TeX one uses a hyphen, and except in \text{} mode, it gets rendered as a minus sign.)
* \max is a standard operator name in TeX.
:: wrong:  n_{max} - 1 \, 
:: right:  n_\max - 1 \, 
: Among the effects of \max rather than {max} or the like are that it is not italicized, it has proper spacing before and after it, thus
::  5\max A \, 
: and subscripts are suitably positioned in expressions like this:
::  \displaystyle \max_{x\in S} f(x) \, 
Michael Hardy (talk) 16:08, 1 October 2012 (UTC)
thread_title:  punctuation and mathematical notation 

message: The copyright issue has been addressed in the email sent to permissions-en@wikimedia.org.
The referred material has been licensed under the terms of the Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA) and the GNU Free Documentation License (GFDL) as shown in the license page.
Oritnk (talk) 20:28, 14 October 2012 (UTC)
replies: text: We have received that email, and I have removed the copyvio notice. Thanks, Legoktm (talk) 07:16, 26 November 2012 (UTC)

text: Addendum: per the OTRS ticket, , , and  have been released under a CC-BY-SA-3.0/GFDL license, and may be included in the article. Happy editing, Legoktm (talk) 07:19, 26 November 2012 (UTC)
thread_title: Copyright issue

message: It’s a shame that Wikipedia is letting anyone come in anonymously with a blanket accusation about copyright infringement without even bothering to tell exactly where in the text the copyright was being infringed, so that people could take immediate action and fix the problem.
The gene expression programming article is a big one and it was written specially for Wikipedia. So saying that it infringes copyright without saying exactly where, can only be perceived as intending to paralyze and disrupt. And since Wikipedia is letting anyone come in anonymously and close a page that took great effort and dedication to write, I don’t think we are encouraging the people who are contributing constructively to Wikipedia, on the contrary.
Oritnk (talk) 13:51, 15 October 2012 (UTC)
replies: text: I think in these cases we tend to stay more on the cautious side and hide everything. There definitely was copyright infringement though. It was resolved by the copyright owners donating their text under a compatible license. Legoktm (talk) 07:18, 26 November 2012 (UTC)
thread_title:  Copyright policy