Instead of portrait and landscape matrices, I myself use tall and wide
matrices, terminology I first heard used by Eugene McDonnell.

On Wed, Feb 17, 2016 at 11:18 AM, Mike Day <[email protected]>
wrote:

> I started with the rectangular case,  so have this rather more complicated
> monad:
>
> deo =: 13 : 's$i{;y[ i =. /:;</.i.s =. (((+/(],%)>./)@:(#every)))y'
>
> I was a bit surprised that the result is tacit.
>    deo
> (+/ (% , ]) >./)@:(#&>) $ ; {~ [: /: [: ; [: </. [: i. (+/ (] , %)
> >./)@:(#&>)
>
> As Marshall observes,  it's not possible to deduce the orientation of
> the rectangle.  The verb here assumes a landscape shape.
>
> Unfortunately,  the result is wrong if the original was portrait...
>
> eg
>    [land  =: </.(a.{~97+i.25){~i.3 8
> +-+--+---+---+---+---+---+---+--+-+
> |a|bi|cjq|dkr|els|fmt|gnu|hov|pw|x|
> +-+--+---+---+---+---+---+---+--+-+
>
>     [port =: </.(a.{~97+i.25){~i.8 3
> +-+--+---+---+---+---+---+---+--+-+
> |a|bd|ceg|fhj|ikm|lnp|oqs|rtv|uw|x|
> +-+--+---+---+---+---+---+---+--+-+
>
>    deo land   NB. ok
> abcdefgh
> ijklmnop
> qrstuvwx
>
>    deo port    NB. !!!
> abcfilor
> dehknqtu
> gjmpsvwx
>
> This dyad allows us to specify landscape or portrait with the
> optional left argument;  explicit odd x forces portrait; the default
> is landscape.
>
> deod =: 3 : 0
> 0 deod y
> :
> s =. (((+/(] (x |.,) %)>./)@:(#every)))y
> i =. /:;</.i.s
> s$i{;y
> )
>
>    deod land
> abcdefgh
> ijklmnop
> qrstuvwx
>
>    1 deod port
> abc
> def
> ghi
> jkl
> mno
> pqr
> stu
> vwx
>
> I've assumed that the input is properly derived from oblique
> boxing of a rectangular array.
>
> Mike
>
>
>
> On 17/02/2016 17:42, Marshall Lochbaum wrote:
>
>> deoblique =: ($:~ [: ((1+i.,i:)>./) #@>) : ([ $ (/:&; </.@:i.)~)
>>
>
>
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