Talk:Array (data type)

Requested move

[[Talk:Array data 

User:Cyberc|Cyber]] ([[User talk:Cyber 01:41, 16 May 2011 (UTC) User:Aervanath|Aervanath]] (talk) 18:11, 25 May 2012 (UTC)

Removed illogical note about elevator buttons in France

This note was (sorry) stupid for the following reason: in french there is no equivalent to floor, instead the word used (and thought) étage means so-to-say "over-floor". Thus, étage 1 is english floor 2. And floor 1/ground floor logically is étage 0, that is in fact a non-étage; this also fits pretty well with underground levels numbered from -1 down. (I guess in english-speaking countries there probably is no 0 button, just like there is no year 0?)

denis ''spir'' (talk) 17:31, 9 December 2012 (UTC)

@Denispir:: Well, I hear that in Britain, the first floor is a level above the ground floor... —SamB (talk) 22:43, 4 July 2015 (UTC)

Dubious

Regarding this bit: Thus, an array of numbers with 5 rows and 4 columns, hence 20 elements, is said to have dimension 2 in computing contexts, but represents a matrix with dimension 4-by-5 or 20 in mathematics. My informal impression is that it's common to speak of a matrix as $m\times n$-dimensional, but much less so to call the product $mn$ the dimension. Something like the latter only happens when one considers a set of matrices as a vector space; for example, the set of all $n\times n$ self-adjoint matrices forms a $n^{2}$-dimensional vector space, in which the natural counterpart of the dot product is the Hilbert–Schmidt inner product. But that notion of dimension depends upon which space the matrix is regarded as belonging to. XOR'easter (talk) 14:55, 7 January 2023 (UTC)

I agree. The language here is subtle, and there is a real danger of editors coining their own idioms. It is correct, both technically and culturally, to say that the set of 4 x 5 matrices forms a 20-dimensional vector space. But it is incorrect, at least culturally, to say that a 4 x 5 matrix is 20-dimensional. A big reason is that 4 x 5 matrices and 2 x 10 matrices (for example) are really dissimilar, despite having the same overall "dimension". Mgnbar (talk) 19:44, 7 January 2023 (UTC)