Talk:Tree (data structure)

message: Problem. Are B+ trees are not trees? I don't buy the definition used in the page. 168.28.180.30 (talk) 14:13, 27 November 2017 (UTC)
replies: text: I (almost) reverted your edits in the article, since I couldn't see at B+ tree why it shouldn't be subsumed under the definition given here. Could you please explain your above conclusion? - Jochen Burghardt (talk) 23:27, 27 November 2017 (UTC)
thread_title: B+ trees

message: I just dropped the "Unordered tree" subsection of "Mathematical definition". A lot of material there does not in fact appear to be defining the tree data structure, but relating trees to other mathematical structures, which is wandering off topic. That sort of thing might be more relevant to Tree (graph theory) or to the other mentioned mathematical structures. There were also some mention of how trees are used in specific applications. It's weird to have examples of applications mixed in with what is supposed to be a section on definitions, so I moved those mentions to the "Applications" section. 
In addition to the problems of length and relevance, the material I removed was almost entirely unreferenced. (There were a few references that support one line each out of a long section, which it wouldn't make sense to leave in on their own without context.) Wikipedia:Verifiability requires that material "any material whose verifiability is challenged or likely to be challenged" have inline citations to reliable sources. Given the perils of relying on editors to verify abstract mathematical concepts on their own, I'm hereby requesting those citations before any material is re-added. -- Beland (talk) 18:38, 3 April 2022 (UTC)
thread_title: Unordered tree section

message: I dropped this section as well. It had similar problems in that most sections introduced possibly original concepts not supported by citations and not part of the definition of a tree. In some cases there were citations that failed verification of the claims they were supposed to support. Some of the material here had more to do with tree traversal or XPaths than defining trees, and is out of scope of this article.
The first two sections (the intro to "Ordered tree" and "Definition using horizontal order") did have plausible references (though there are some opinions that fail verification and violate WP:NPOV, and probably not all the other material in these sections is actually supported by these sources) and were reasonably related to the purpose of giving a mathematical definition. I dropped these sections because they appear to be defining the concept in graph theory, and so would be more appropriate at Tree (graph theory)#Ordered tree. I did not move them there because 1.) it seems like too much detail for that article, and 2.) there are cross-references to other (deleted) sections in this article which would need to be cleaned up. If you want to restore a cleaned-up version of this material on that article, my advice would be to make it a lot shorter, possibly just citing the referenced sources and noting that they give formal definitions, so anyone who is interested in that can just click through to those articles. -- Beland (talk) 20:38, 3 April 2022 (UTC)
thread_title: Ordered tree section

message: "Alternatively, a tree can be defined abstractly as a whole (globally) as an ordered tree,..." 
OR (A concretely defined tree does not require separation to be ordered)
"with a value assigned to each node. Both these perspectives are useful: while a tree can be analyzed mathematically as a whole, when actually represented as a data structure it is usually represented and worked with separately by node (rather than as a set of nodes and an adjacency list of edges between nodes, as one may represent a digraph, for instance). For example, looking at a tree as a whole, one can talk about "the parent node" of a given node, but in general, as a data structure, a given node only contains the list of its children but does not contain a reference to its parent (if any)."
ADDING
You hide the root NODE and declare the parent node the same as "the child node". I maintain, this is bad form, let's start with computationally... And I have but momentarily tempered my accusing for the sake of one...  — Preceding unsigned comment added by 156.99.40.14 (talk) 18:30, 27 November 2021 (UTC)
replies: text: I've removed this content from the article. -- Beland (talk) 09:09, 2 April 2022 (UTC)
thread_title:  Reflection of separateness 

message: There is a move discussion in progress on Talk:Associative array which affects this page. Please participate on that page and not in this talk page section. Thank you.  —RMCD bot 00:32, 27 January 2022 (UTC)
thread_title:  Move discussion in progress 

message: Merge this page with https://en.wikipedia.org/wiki/M-ary_tree ? Or at least state what the difference is more clearely.  — Preceding unsigned comment added by Agowa (talk • contribs) 08:09, 10 May 2022 (UTC)
thread_title:  Dupplicate of m-ary tree