Talk:Moore neighborhood

Merge reverted

I've reverted the merging of this article into Cellular automaton, since it didn't really fit in there and that article is long and rambling enough already anyway. This could be turned into a section in a generic Neighborhood (cellular automata) article, but I see no real problem with it remaining as a separate short article either. —Ilmari Karonen (talk) 17:53, 17 December 2006 (UTC)

Evolvable reproducing patterns yet?

Has there been any success with any rule sets in the Moore neighborhood for creating a self-replicating, evolveable CA? It seems like people keep getting "almost there" in the VN neighborhood... if there hasn't been any legitimate success in the Moore neighborhood yet, perhaps the problem is related to being 2-dimensional. Having only 2D imposes one hell of a lot of topographical restrictions in terms of how shapes can possibly interact, most notably that its impossible to have two separate but interlinked objects in a 2D space. Zaphraud (talk) 02:52, 1 May 2008 (UTC)

Clarified algorithm

I just had to implement the alg and I found the original description confusing, particularly the definition of the backtrack step. I've tested and verified the changes I've made. Ling noi kidu (talk) 00:09, 10 August 2011 (UTC)

Incorrect neighborhood

"The Moore neighborhood of a point is the points at a Chebyshev distance of 1."

This neighborhood is different from the one defined in the cited reference; specifically it does not include the center point itself. Mathworld cites Gray and they have identical definitions. Gray's article is a response to Stephen Wolfram's work "A New Kind of Science" which does not explicitly speak of the Moore neighborhood but mentions that the 5-cell neighborhood was considered by Moore. — Preceding unsigned comment added by Arketyp (talk • contribs) 12:31, 23 July 2013 (UTC)

Definition of the neighb.

I have changed the definition of the neighbourhood to include the cell itself. Although this may look non-intuitive for persons not familiar with CA literature, there is a strong reason on why the neighb. should include the central cell itself: in the formal definitions of CA, the neighbourhood represents all the cells to which the central cell have access. A definition where the central cell is excluded is well possible and it simply means that a cells ignores its own state.Baba Arouj (talk) 13:29, 17 August 2016 (UTC)

Inconsistency in counting central cell within the environment

In many other wikipedias (french, spanish, portuguese - probably one common ancestor) it is clearly said the central cell should not be counted, the formula being: $(2r+1)^{2}-1$. In the article in english it says both:

• The Moore neighborhood is composed of nine cells: a central cell and the eight cells which surround it.

However in 3D the center is not counted:

• The concept can be extended to higher dimensions, for example forming a 26-cell cubic neighborhood

What should be the proper definition regarding the number of cells of Moore neighborhood? Hexagone59 (talk) 09:51, 6 January 2019 (UTC)

Certainly most cellular automata (including Life) have behavior that depends on the value of the central cell and not just on the surrounding cells, although they treat the central cell a little differently (not just counting it towards the total count of nearby live cells). In that sense, the central cell is part of the neighborhood, where the neighborhood of a cell is the set of all other cells it depends on. —David Eppstein (talk) 19:24, 6 January 2019 (UTC)

"Algorithm" section is odd

The section called "Algorithm" oddly claims that "The idea behind the formulation of Moore neighborhood is to find the contour of a given graph." But this is just one out of many, many things the Moore neighborhood can be used for. This application is in no way fundamental, and the detailed algorithm given is for a sequential computer, whereas the term is most commonly used in relation to cellular automata, as the introduction correctly indicates. A cellular automaton can find all boundary pixels in a single step, since every pixel can immediately see whether it is on the boundary or not, making this algorithm irrelevant.

The Moore neighborhood is a very simple and natural concept, used by many people even if they never heard the term "Moore neighborhood". Just because we see it used for some application does not mean that that is its main use. This algorithm is not the main use of the Moore neighborhood, and its domination of this article is strange. Moore neighborhoods are used all over the place, but the main use of the term "Moore neighborhood" is when describing a cellular automaton neighborhood, deriving from how Moore often used this neighborhood in his pioneering work on cellular automata. 130.60.6.54 (talk) 12:29, 22 March 2019 (UTC)