Talk:Glossary of graph theory
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[edit] Merging and Organization
I don't think this page should be merged into graph theory. It was deliberately created to list definitions. Charles Matthews 16:41, 21 Mar 2005 (UTC)
- I only skimmed articles in question (i.e., graph theory, glossary of graph theory and graph (mathematics), but it seems there is a fair amount of overlap. The question, I think, is not if we should merge the two articles, but how we can make distinction among those articles; maybe one idea is let graph theory be the overview article, then create subtopic articles like properties of graphs (degree, Hamiltonian and such), or an article about directed or undirected. Merely listing definitions is really a bad idea. Besides, if this is a glossary, should each line stars with a bold term followed by the definition? -- Taku 19:16, Mar 21, 2005 (UTC)
This page is 30K of minor definitions. The idea is to have many redirects to it, rather than one page for each small definition. That is what a glossary page is supposed to do. Clearly 30K is too much to put into graph theory, which should give a broad introduction only.
So, I really don't see what the problem is with this. There are quite a few other examples, e.g. general topology and glossary of general topology.
Charles Matthews 20:38, 21 Mar 2005 (UTC)
OK, it seems that the correct idea is to merge graph (mathematics) into graph theory. But this page is fine as it is. Charles Matthews 20:41, 21 Mar 2005 (UTC)
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- Please don't try to merge the new stuff (recently moved from Graph theory) into the stuff that was already here. The new stuff is "Graph theory glossary for Dummies"; the old stuff is more like a Reader's Digest Condensed version of Graph Theory 101.
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- I promise I will do as I indicated at Wikipedia talk:WikiProject Mathematics#Graph (mathematics) vs Graph theory: drag all the content into a few user pages, stir them around, and organize them so that readers at different levels can make good use of them. Only then will I offer the refactoring to the project. It's not my place to say who will edit what when, but I'd be grateful if I didn't have to try to hit a moving target. — Xiong (talk) 03:47, 2005 Mar 22 (UTC)
As you know, we are all free to edit here as we see fit. That being said, it is more helpful to be more explicit. Charles Matthews 10:02, 22 Mar 2005 (UTC)
I think (as a newbie to graph theory) that we should remember who our audience is. It is me. I was directed to the glossary by several of the pages, because I thought I would get a better grasp of the term that was being defined on another page. What I found was a very incomplete definition that was disjointed from the supporting terms and concepts. For a glossary (which is typically a collection of disjointed definitions) to be useful, it should contain concepts which are easy to understand on their own, without having to understand the rest of the glossary. Otherwise, I, the learner, end up skipping back and forth between concepts trying to piece together a picture of what is being said. When I do that, I am essentially creating my own encyclopedia article in my mind in order to construct the full picture of the concept. But what if I don't have some of the pieces? As a learner of new information, it would be much better to have someone break down the knowledge ontologically into the correct sequence or taxonomy of ideas so that one idea builds upon the other. A glossary is a cheap imitation of doing that and should be reserved for more disjointed kinds of understanding, like quickly finding the definitions of acronyms used in telecommunications or something like that.
What I would like to see is each idea more fully developed to include separate illustrations to provide examples of each type of graph element. The concepts are much easier to understand when you have that kind of visual map presented to you. We are talking about graphs, here, so more graphs are better. Each graph should have more explicit instructions on how we are explaining it, by using colors and numbers, perhaps, to highlight various sections. That's just my two cents worth. TimIngalls 22:58, 15 November 2006 (UTC)
- I agree that this page seems messy. The glossary of general topology page that Charles Matthews pointed out looks much cleaner. Do we want to head towards something like that? The "To be merged" section looks like it is already trying to. If we had the glossary organized alphabetically it would also clear up the 'order of definitions' issue, as Quintopia noted.
- I haven't read through all of the discussion pages yet, but it looks like Xiong still wanted to do some work on this before he left. I'd hate for his hard work to be undone if I make changes without understanding the intent. Is there a consensus on what we should do here? --Culix 08:28, 7 December 2006 (UTC)
[edit] Order of definitions
It seems to me that no definition on this page should incorporate a term that is defined later on the page. It should be that any term that requires another term as part of its definition should come after the other term is defined, so that someone with no knowledge of graph theory reading the page from top to bottom would never have to stop and say "Oh, I don't even know what that means," and have to go search for it before continuing. Thus, the section on trees should come after the section on connectivity because trees and subtrees are defined to be connected.
The other option is to put everything in alphabetical order so that if someone does have to look up another term in the definition they won't have to search, but this is a huge change.--Quintopia 09:17, 25 October 2006 (UTC)
[edit] Direction: head/tail
Under Direction an arc is defined to de directed from the head to the tail. This is just the opposite of the definition in Graph (mathematics). There, the edge is directed from x to y, where x is the tail and y is the head. Who's wrong?
- I agree, the direction of an arc is always from tail to head, both referring to the components of an arrow, which are frequently used to draw the arcs of a directed graph. DVanDyck 16:40, 11 August 2006 (UTC)
[edit] knots
what's this definition of knots? it should be written if there is a link with knots of knots theory. and it should be explained more what are they and what they mean and what they imply! achab
[edit] Minor
I find the definition of "minor" given here to be incomprehensible. What on earth does "every edge in E2 corresponds to a path (disjoint from all other such paths) in G1 such that every vertex in V1 is in one or more paths, or is part of the injection from V1 to V2" mean? I suggest defining "edge contraction" first then defining "minor" like at Minor (graph theory). 202.45.98.61 12:43, 13 June 2006 (UTC)
- Indeed, this is the most common and clearest way to define "minor", and in addition consistent with the Minor (graph theory) page. DVanDyck 11:39, 13 August 2006 (UTC)
[edit] Request for More Illustrations
The discussion above regarding whether there needs to be a glossary or not could
[edit] Questions
- I can not find the answer to the following question on the page:
How is a graph called, where edges might also be vertices?
217.83.100.240 13:55, 28 September 2006 (UTC)
- Fourth paragraph in "Walks" section: If a path (stated without qualification) is usually defined to be simple, and if simple means that every vertex is incident to at most two edges, then doesn't the fact that in the example graph 5 is incident to 3 edges mean that (5,2,1) isn't a path? Or maybe I'm not clear on what "incident to n edges" means? Or was this meant to be an example of an old usage of the term 'path'? I find this paragraph to be slightly confusing, if not self-contradictory. -Jesse again
- I can not find the term "dicycle" explained in the graph theory glossary.
- I followed a link to 'Tournament' in the article Probabilistic method and ended up here, where there's no mention of tournaments.. I'm left with absolutely no idea of the word's meaning.
- Look again! It's there now! --Quintopia 09:17, 25 October 2006 (UTC)
- What are vertex disjoint cycles? 220.226.9.173
[edit] Thanks
I think it is extremely helpful to have a glossary page. Thank you to whoever started this. I found a small problem, however, with the formula for the length of a walk (open, l=n-1; closed, l=n; n is number of vertices visited). It doesn't work for the example given directly below it. I believe this formula would work for a trail, but it doesn't work for a walk that has repeated edges. Of course you could decompose each walk into trails and then apply the formula, and that should work. I should mention that I am merely a lowly undergraduate, and I could be wrong about all this. If so, boy won't my face be red. Anywho, great page. -Jesse Supina, U of L (still don't know how that signature thing works)