Talk:Oval

Oval is also a set of points

i am very new to the system, but as i was taught an oval is also a set of q+1 noncollinear points in PG(2,q) There should be a separate page for that in the projective geometry subcategory But how can I do request to start on that when i have to request here http://en.wikipedia.org/wiki/Wikipedia:Requested_articles/Mathematics — Preceding unsigned comment added by Evilbu (talk • contribs) 12:11, 2006 February 4 (UTC)

I'll add that comment to the page, and add a red link like this: oval (projective plane). It's very simple to start an article that way. Charles Matthews 12:29, 4 February 2006 (UTC)

Thanks i can do that later. But is that THE way to start a new page. Suppose i would want to make an article about something that has no relation to any others so there is no link like you just made somewhere, what do I do? I really find that difficult here.Evilbu 16:05, 4 February 2006 (UTC)

Type anything into the search box, for example QQQQQ. Click on Go. Then you will get a page saying there is no such page. From there it is fairly obvious: you click on the 'create this article link'. That immediately takes you to an edit box. Notice that the page you get is called http://en.wikipedia.org/w/index.php?title=QQQQQ&action=edit. So, if you like knowing the syntax for everything, just put that in your browser with QQQQQ replaced by any page name (use _ underlines for spaces, though).

But good advice is not to create 'orphan pages'. How will anyone find them? Start with a link from your user page, for example.

Charles Matthews 20:08, 4 February 2006 (UTC)

Created oval projective geometry

I made the article (stub) explaining what an oval in a finite projective plane is. I strongly suggest a disambiguation page now. What do you think? Evilbu 23:10, 2 March 2006 (UTC)

Stadium

http://mathworld.wolfram.com/Stadium.html

According to this source the second picture (rectangle + 2 semicircles) is not considered an oval and is in fact a stadium. I suggest removal of this picture, and the creation of a Stadium (geometry) page. Who's with me? —The preceding unsigned comment was added by 203.38.122.195 (talk) 22:51, 7 March 2007 (UTC).

I disagree. Wikipedia is at times lampooned in the real world for its pedantry, and this is a such an example. In the real world, where real people use this website to find information, this "rectangle with semi-circular rounded ends" shape is also called an oval. Various kinds of athletic tracks (track and field, horse racing, auto racing) refer to tracks in this shape as "oval". The definitions of oval in my dictionaries lists this shape as "oval" as well as the traditional ellipse-like shape. These same dictionaries do not mention anything about a shape for the word "stadium". A stadium (1) is a large, usually open air structure used for athletic events; (2) a measure of distance in ancient Greece. While mathematics may be useful for describing shapes, it does not have complete hegemony over them. People define common shapes through their experiences with the physical world, not mathematicians and pedants, and real people looking for real knowledge use this website. I can't imagine why anyone who would refer to the "rectangle with semi-circular rounded ends" shape as a "stadium" would have need for Wikipedia to find out information about it.Mike5816 (talk) 13:59, 17 May 2011 (UTC)

The description in the article for an "oblong" is actually the exact definition of a Stadium (geometry). An "oblong" is not actually so precisely defined - just look at the cited dictionary entry. When an "oblong" consists of an exactly rectangular middle part and both rounded ends are exactly semicircles it is in fact exactly a "stadium". Thus a stadium is a specific type of oblong but here it is being described as if all oblongs are stadiums. Roger (Dodger67) (talk) 11:32, 19 May 2013 (UTC)

Renaissance Oval

I'm not sure which better name can be set on this http://images.google.pt/images?q=renaissance+oval

This kind of Oval (maybe the very first time a geometric shape were called as Oval), were made of 4 90-degrees circle arcs - 2 largers (along the shape lenght) and 2 smallers (on the edges), like shown at http://img515.imageshack.us/img515/4995/ovalld1.png

Please help me looking for more complete information, and the whole geometric drawing history related to this. —Preceding unsigned comment added by Nitrofurano (talk • contribs) 16:47, 2 October 2008 (UTC)

Racetrack oval

In common usage, oval also covers racetrack shapes: rectangles with semicircles on two sides. What is the technical term for this shape?

--JamesWim (talk) 09:16, 8 November 2008 (UTC)

It's a Stadium (geometry). Roger (Dodger67) (talk) 11:38, 19 May 2013 (UTC)

Non-tangent

By the way, the intersection of two circular arcs such that the curves are not tangent at the intersection points is a crescent or gibbous... AnonMoos (talk) 16:00, 8 February 2010 (UTC)

Three dimensions?

Can an oval be three-dimensional? Isn't that like calling a sphere a circle? Surely the correct term for a 3D oval is an oblate spheroid. Norman21 (talk) 21:33, 20 February 2010 (UTC)

An oblate spheroid is a 3D ellipse, not oval.. AnonMoos (talk) 01:16, 21 February 2010 (UTC)

Well, is the term ellipsoid appropriate? Surely there must be something more technical than "egg shaped"...! Norman21 (talk) 16:37, 27 February 2010 (UTC)

"Ellipse" and associated terms refer to the specific geometry of a circle scaled by different factors along different dimensions. If you take circular arcs scaled by the same factor along all dimensions, then no matter how you rotate them, you won't get elliptical geometry, so terms tending to imply elliptical geometry should be avoided... AnonMoos (talk) 17:33, 27 February 2010 (UTC)

Does that mean the phrase "the term egg-shaped ... may also refer to true prolate ellipsoids" in the article ellipsoid is incorrect? Norman21 (talk) 13:44, 28 February 2010 (UTC)

Not too sure what you're asking; "ellipse" is a technical term in geometry, while "egg-shaped" is a vague impressionistic term which has no precise geometric meaning, as far as I'm aware... AnonMoos (talk) 19:50, 28 February 2010 (UTC)

Well, a picture of "a vague impressionistic term" has just appeared in the article. I ask again - can an oval be three-dimensional? Norman21 (talk) 06:40, 19 March 2010 (UTC)

It's an ovoid. The wonders of English is that such a word exists by analogy, and also is in the dictionary: sphere:spheroid, ellipse:ellipsoid, and so on.Mike5816 (talk) 13:59, 17 May 2011 (UTC)

Thank you! It took over a year, but at last I have an answer to my question! Norman21 (talk) 15:49, 18 May 2011 (UTC)

not an ellipse

2011-04-20 - What kind of definition is: "an ellipse, but not an ellipse"?? —Preceding unsigned comment added by 79.192.221.104 (talk) 12:05, 20 April 2011 (UTC)

In the "Oval in geometry" section, I italicized "resembling" for empahsis, but I'm not sure that's correct. Does the definition include certain shapes that somewhat resemble ellipses while excluding true ellipses? Folklore1 (talk) 20:33, 28 March 2012 (UTC)

Ah, you have stepped into a hornet's nest. There are several "flavors" of geometry and in the viewpoint of some of these, this section does not make much sense. Speaking as a projective geometer, ellipses are clearly ovals and the differentiable property mentioned in the section is meaningless (it would be replaced by the statement that at each point of the curve there is a unique tangent line). A differential geometer would probably have a different take on this, and the algebraic geometers wouldn't want to get involved since the concept is not precise enough to be dealt with using their tools of trade. I have been reluctant to change this section because I'm not sure what could go in its place which would be acceptable in a majority of geometric viewpoints. The lack of references, however, does make it fairly easy to envision a wholesale change in the section, so the issue you raise may become moot. And by the way, thanks for the copy editing that you have done on this page — that job takes more patience than I usually have. Bill Cherowitzo (talk) 02:19, 29 March 2012 (UTC)

What is that equation???

Refer to the following equation for an approximation of a 3D egg where a is any positive constant:$x^{2}+y^{2}+z^{2}(1.5cos((z+a/2)/a))^{2}=a\!$

Where did the equation come from? When I plot it, I get nothing that looks like an ovoid. Here's what I get for a=1:

Plot of equation from wikipedia "oval" article.

Miguelacevedo (talk) 00:28, 13 August 2013 (UTC)

It's not obviously helpful, is it? I'll cut it. (It was added 16 September 2010 by 63.195.83.157, without explanation.) —Tamfang (talk) 07:12, 26 September 2014 (UTC)

Ratings Template

I'm rating this article as low priority. Bryanrutherford0 (talk) 16:50, 17 October 2013 (UTC)

Disruptive editing

A user has continually tried to place this sentence into the lead.

Also known as weird unda in the language common to South Indians known as Malayalam.

I have reverted each attempt since the statement has no citation. A more fundamental objection is that there are thousands of languages and/or dialects and each one has some representation of the word "oval". What makes this one so special that it needs to be recorded here? I will continue to revert unless some reason is forthcoming. --Bill Cherowitzo (talk) 23:21, 5 August 2016 (UTC)

Wiktionary shows "unda" as meaning "wave", or "lost" (adjective) in Kurdish.. I don't get anything on Google searching for "unda oval".

Jimw338 (talk) 17:14, 28 August 2016 (UTC)

An Oval need not have a Symmetry Axis

I guess the oval definition in this wikipedia article is wrong. The German wiki has a mathematical definition which does not require a symmetry axis. Here is a picture of an oval without a symmetry axis: https://de.wikipedia.org/wiki/Oval#/media/File:Eikuve.svg

The German mathematical definition is simply: "Eine geschlossene zweimal stetig differenzierbare konvexe Kurve in der Ebene heißt Oval (auch Eikurve oder Eilinie)". I therefore did an edit of the article.

Jan Burse (talk) 20:40, 7 August 2017 (UTC)

There is always going to be a problem with trying to give a precise definition for a vague concept. The German definition you have given above may be fine in differential geometry, but, as the German article points out, this definition is not general enough to cover all curves that may be called ovals. It may be in the eye of the beholder whether to call a curve an oval or merely oval-ish. Although I have great respect for Kmhkmh's work, I would not call the diagram he has provided on the German page an oval; ovalish perhaps, but I actually expect to see an axis of symmetry because an oval in the Euclidean plane is more of a visual object than a mathematical one. (And, just to set the record straight, in my own work, ovals in finite projective geometries do not have axes of symmetry, but do have precise definitions.)--Bill Cherowitzo (talk) 23:48, 7 August 2017 (UTC)