Talk:vector

The following information passed a request for deletion.

This discussion is no longer live and is left here as an archive. Please do not modify this conversation, but feel free to discuss its conclusions.

rfd-sense: (psychology) "a recurring psychosocial issue that stimulates growth and development in the personality"

not in 2 psych dictionaries in this sense, incl APA 2006, contibutor cites one author in edit summary. DCDuring TALK 15:51, 13 February 2008 (UTC)Reply

A section about Arthur Chickering from Professional Orientation to Counseling may shed some light on this use of the word "vector". It still sounds to me like an application of a generic term for a specific purpose that may not be widely recognized as a new connotation, but I'm not a psychologist (nor do I play one on TV). Interestingly, I hadn't read the edit summary of the addition of this sense before I checked, so the fact that my quick search yielded the same Chickering weakly reinforces the idea that this is a very uncommon connotation, maybe only in use by a single professional. Broader evidence is certainly called for. ~ Jeff Q (talk) 21:43, 14 February 2008 (UTC)Reply

Kept per this cite --Jackofclubs 18:56, 8 June 2009 (UTC)Reply

The following information passed a request for deletion (permalink).

This discussion is no longer live and is left here as an archive. Please do not modify this conversation, but feel free to discuss its conclusions.

msh210 and Keφr seem to be fairly inactive as of late, but we are in need of mathematicians. To me, the first three definitions all seem like various parts of the true mathematical definition of a vector. They are mathematically distinguishable, but not lexically distinguishable, in the sense that I don't think one could find a use exclusive to any of those definitions that did not fall under all of them, hence my belief that they ought to be merged. That said, I await the judgement of more knowledgeable individuals, especially with respect to what the merged definition would look like. —Μετάknowledge^{discuss/deeds} 03:50, 13 April 2015 (UTC)Reply

I think the three mathematical definitions could be condensed to two definitions, but I'd be unwilling to have a single one. What the three senses we have at the moment effectively mean is:

1. A mathematical quantity consisting of a magnitude and a direction.
2. A mathematical quantity represented in a format like (x,y,z), which can be thought of as representing a magnitude and a direction.
3. A mathematical quantity which can be meaningfully added to another quantity of the same type, and also multiplied by a scalar

Sense 1 is arguably a subsense of sense 2 (or possibly vice versa), although there are ways of representing magnitude and direction vectors that aren't ordered tuples (for instance, "1 mile in a north-westerly direction" is a vector), and there are ordered tuples for which magnitude and direction are physically meaningless (quantum physics uses vectors as a convenient way to represent the state of particles, but these vectors aren't directly related to any distance or angle in the physical world - rather, they only 'exist' in a mathematical abstraction called a Hilbert space - and supercomputers often represent all sorts of data in vector format just because that's easier for parallel processors to handle). Both of these senses are solidly from the realm of applied mathematics. Sense 3 on the other hand is restricted almost entirely to pure mathematics. These vectors do not necessarily have anything at all to do with distances and magnitude, and they don't necessarily even represent numbers - they could be functions, matrices or even entire fields of numbers. The only thing that makes them vectors is the fact that they have two properties: you can add them together, and you can multiply them by scalars (typically, this means just a straightforward real number). Now, sense 1 and 2 are both technically redundant to this sense, but this sense is so vague and so far removed from our everyday intuition of a vector that we wouldn't help anyone by merging all the senses here. I would suggest instead having:

1. A member of a vector space.
   1. (Mathematics, physics) A directed quantity, one with both magnitude and direction; the signed difference between two points.
   2. (Mathematics, physics, computing) A mathematical quantity represented by an ordered tuple.
   3. (Pure mathematics) A mathematical object representing a member of a space on which addition and scalar multiplication are defined.

Any suggestions are of course welcome. Smurrayinchester (talk) 08:04, 13 April 2015 (UTC)Reply

• Never really been a fan of organizing things as definition, subdefinition. I think it's fine the way it is. Purplebackpack89 20:27, 13 April 2015 (UTC)Reply
  • Eh, might as well vote keep. I haven't been convinced that this should be deleted and it's certainly not an SOP case. Purplebackpack89 14:06, 11 May 2015 (UTC)Reply

Our current senses are:

1. (mathematics) A directed quantity, one with both magnitude and direction; the signed difference between two points.
2. (mathematics) An ordered tuple representing a directed quantity or the signed difference between two points.
3. (mathematics) Any member of a (generalized) vector space.

IMO these are distinct even lexically. (I read the nomination above, and not, fully, the replies thereto, so forgive me if I repeat something already said. Thanks for the ping, by the way.) When a high-school physics teacher refers to velocity as a vector as opposed to speed, which is a scalar, he means sense 1, not sense 2 or 3. (Velocity is a vector in sense 3, certainly, and can be re-defined so it's a vector in sense 2, I suppose, but neither of those is what the teacher means.) When a high-school math teacher says " is a vector", that's clearly sense 2 (and only possibly sense 1). So we need 1 and 2 both. And of course 3 is different, including e.g. polynomials.​—msh210℠ (talk) 21:20, 13 April 2015 (UTC)Reply

• Keep the three separate as per msh210 above. I disagree with the reformulations made above; in particular, in the 3rd sense, vector space meets certain axioms which the redefinitions fail to ensure. The definitions in this revision are good "as is". The axioms are listed e.g. in Wolfram Mathworld. --Dan Polansky (talk) 11:05, 18 April 2015 (UTC)Reply

• Keep. @Metaknowledge, Smurrayinchester, Purplebackpack89, Msh210, Dan Polansky: these are technical senses, yet not one has a single WT:CFI attested usage. How, besides sharing common knowledge, is a discussion possible. Dan, at least makes the effort to point to a dictionary. The nuance needs attestation. —BoBoMisiu (talk) 22:38, 9 May 2015 (UTC)Reply
  • I didn't vote delete, I merely took issue at the organization of the entry. Purplebackpack89 03:43, 11 May 2015 (UTC)Reply

Senses kept. Perhaps the definitions could be made more clearly distinct, however. bd2412 T 21:32, 3 June 2015 (UTC)Reply