I forgot to point out earlier that
6 12 $ ? 72 $ 10
may be defined more succinctly as
? 6 12 $ 10
FWIW, I had a look at an alternative approach, working on the union of
all rows:
union =: ~.@:, NB. ie nub of the ravel
rix =: (] #~ */@:(e."1)~) union NB. another row intersection verb
It works, but is more verbose, uses more memory and more cp time for
the limited
cases I've explored.
Mike
On 01/09/2017 08:40, 'Mike Day' via Programming wrote:
The main requirement is to obtain the set-intersection of the rows:
rowintersection =: ([-.-.)&~./
(The &~. isn't essential, but it will save space for large arrays
with significant repetition.)
(Drafting this, I see Raul's beaten me to it, though he didn't
include the &~. !!!)
Also,
colintersection =: rowintersection@:|:
Cheers,
Mike
On 01/09/2017 07:48, Skip Cave wrote:
]a =: 6 12$ ?72$10
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