Not Beta as Bill points out, but better to stick to one thread?!
Anyway, these offerings are more self contained, in using Q's
size implicitly rather than assuming it's known.
I've avoided using @ and @: as Linda eschews them, but am
probably breaking one or two of her rules for straightforward J.
(Apologies if Thunderbird screws up the display)
NB. rotate horizontally by 1 2 3 ...
(|."0 1~(1+[:i.#))Q
BCDA
GHEF
LIJK
MNOP
NB. take horizontally 1 2 3 ...
({."0 1~(1+[:i.#))Q
A
EF
IJK
MNOP
Linda might also find these interesting:
NB. take 1 2 3 ... and then rotate rows horizontally
(([:|.{.)"0 1~(1+[:i.#))Q
A
FE
KJI
PONM
NB. rotate rows by 1 2 3 ... and then take 1 2 3 ... horizontally
(([|.{.)"0 1~(1+[:i.#))Q
A
FE
KJI
PONM
Time & space for one of these on a reasonably large argument:
ts'(([{.|.)"0 1~(1+[:i.#))1000 1000$,Q'
0.00233033 2.9472e6
Mike
On 13/01/2015 14:42, Linda Alvord wrote:
Is there an easier way to get from Q to T in larger situations?
]Q=:4 4$'ABCDEFGHIJKLMNOP'
ABCD
EFGH
IJKL
MNOP
]R=: (1|.'ABCD'),(2|.'EFGH'),(3|.'IJKL'),:0|.'MNOP'
BCDA
GHEF
LIJK
MNOP
]S=:1 2 3 0 |."1 Q
|length error
| ]S=:1 2 3 0 |."1 Q
]T=:(|.i.4)|.!.' '"0 1 R
A
EF
IJK
MNOP
Linda
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