Maybe this?
The longest learning for me with J was to internalize as automatic the
idea that many primitives apply to ITEMS of a noun. The items of a list
are easy. But the items of anything else are its highest dimension.
]a=. 3 4$i.12
0 1 2 3
4 5 6 7
8 9 10 11
then:
]a=. 1 0 1#a
0 1 2 3
8 9 10 11
...because rows are now the items of the 2-d array "a"...etc. So your
boolean intuition was correct.
Tony (a year younger than you, Harvey)
On 2020-05-19 8:55 a.m., HH PackRat wrote:
On 5/19/20, Michael Dykman <[email protected]> wrote:
In functional languages, you don't really delete so much as you make a
fresh copy absent of the undesirable elements.
Where you looking for this?
] a=. <"0 'abcdef'
┌─┬─┬─┬─┬─┬─┐
│a│b│c│d│e│f│
└─┴─┴─┴─┴─┴─┘
0 0 1 1 0 1 # a
┌─┬─┬─┐
│c│d│f│
└─┴─┴─┘
That kind of thing is what gave me the idea of a boolean mask of some
type. However, can this be carried over, applying to rows of a table
instead? I'm thinking that it probably does in some way, but I want
confirmation on that. Thanks for your response!
Harvey
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