Gosh.  Matrices "Comport themselves".  I like it.

Surely an array of rank > 2 is a "space"



Quoting Roger Hui <[email protected]>:

> Donald McIntyre, *Language as an intellectual tool: From hieroglyphics to
> APL, *IBM Systems Journal, Volume 30, Number 4, 1991, page 569:
>
> In 1848 Cayley showed that the combined effect of two rotations could be
> represented as the product of two quaternions, and shortly afterwards
> Sylvester (in the year he introduced the term *matrix*) pointed out that any
> number of rotations can be represented by a single rotation about one axis.
> As we would now say: each rotation can be represented by a matrix, and the
> product of these matrices is a matrix completely describing the combined
> rotation, whose axis is an eigenvector of this matrix, and the angle of
> rotation can be found from the corresponding eigenvalue.  By 1855 Cayley
> used matrix product (calling it the *composition* of matrices), and in his
> memoir of 1858 he wrote: "It will be seen that matrices comport themselves
> as single quantities; they may be added, multiplied, or compounded together,
> etc.: the law of addition of matrices is precisely similar to that for the
> addition or ordinary algebraical quantities; as regards their multiplication
> (or composition), there is the peculiarity that matrices are not in general
> convertible; it is nevertheless possible to form the poewrs (positive or
> negative, integral or fractional) of a matrix ..." [17]  In this memoir he
> uses Sylvester's latent roots (eigenvalues), but without naming them.
>
> [17] A. Cayley, "A Memoir on the Theory of Matrices", Royal Society of
> London, *Philosophical Transactions **148*, 17-37 (1858). Reprinted in
> *Collected
> Mathematical Papers **2*, No. 152 (1889).
>
>
>
> On Tue, Oct 25, 2011 at 5:42 PM,  <[email protected]> wrote:
>> According to this source, you're right.
>>
>> http://www.etymonline.com/index.php?term=matrix
>>
>> S
>>
>>
>> Quoting Devon McCormick <[email protected]>:
>>
>>> I believe I heard (maybe from Ken?) that matrix is from the Latin "Mater"
>>> (mother) because of the various factorization methods that create smaller
>>> matrixes from an original one.
>>>
>>> On Tue, Oct 25, 2011 at 6:15 PM, Alexander Mikhailov <[email protected]
>> wrote:
>>>
>>>>
>>>>
>>>> Having word "matrix" (where it came from?..) and tradition in J to name
>>>> things with non-traditional names (verb, noun), I'd vote for orthotope.
>>>> Unmistakeable, succinct.
>>>>
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: Henry Rich <[email protected]>
>>>> To: Programming forum <[email protected]>
>>>> Cc:
>>>> Sent: Sunday, October 23, 2011 7:10 PM
>>>> Subject: [Jprogramming] The word for arrays of rank > 2
>>>>
>>>> 'cube' was suggested.  Raul objected that a cube should have all axes of
>>>> equal length.
>>>>
>>>> 'cuboid' has been used in Ye Dic (in the description of ;.0).  According
>>>> to Wikipedia a cuboid should have rank 3.  And the word seems strained.
>>>>
>>>> 'hyperrectangle' is used, but it's a fifty-cent word for a ten-cent
> idea.
>>>>
>>>> A fancier word is 'orthotope'.  Great if you're a Greek scholar.
>>>>
>>>> Also, 'box', which would be perfect if we weren't using it already.
>>>>
>>>> How about 'brick'? or 'block'?
>>>>
>>>> I like 'brick', followed by 'cube'.
>>>>
>>>> Henry Rich
>>>> ----------------------------------------------------------------------
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>>>>
>>>
>>>
>>>
>>> --
>>> Devon McCormick, CFA
>>> ^me^ at acm.
>>> org is my
>>> preferred e-mail
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>>
>>
>>
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