Re: [patch] Proposal for \rotate in psql

2015-09-08 22:55 GMT+02:00 Daniel Verite <daniel(at)manitou-mail(dot)org>:

> Pavel Stehule wrote:
>
> > rotate ~ sounds like transpose matrix, what is not true in this case.
>
> The various definitions that I can see, such as
> http://dictionary.reference.com/browse/rotate
> make no mention of matrices. It applies to anything that
> moves around a pivot or axis.
>
> OTOH, the established term for the matrix operation you're
> referring to appears to be "transpose", as you mention.
> https://en.wikipedia.org/wiki/Transpose
>
> I notice that according to
> http://www.thesaurus.com/browse/transpose
> "rotate" is not present in the 25+ synonyms they suggest for
> "transpose".
>
> In the above wikipedia article about matrix transposition,
> "rotate" is also never used anywhere.
>
> "rotate matrix" does not exist for google ngrams, whereas
> "transpose matrix" does.
> https://books.google.com/ngrams
>
> Overall I don't see the evidence that "rotate" alone would
> suggest transposing a matrix.
>
> Now it appears that there is a concept in linear algebra named
> "rotation matrix", defined as:
> https://en.wikipedia.org/wiki/Rotation_matrix
> that seems quite relevant for 3D software.
>
> But as psql is not a tool for linear algebra or 3D in the first place,
> who could realistically be deceived?
>

in the help inside your last patch, you are using "crosstab". Cannto be
crosstab the name for this feature?

Regards

Pavel