[Jprogramming] Deleting?

['Pascal Jasmin' via Programming]

To go from indexes to mask

delitems =: (] #~ [ 0:`[`]} 1 #~ #@])

1 2 delitems i. 7 2

0 1

6 7

8 9

10 11

12 13







On Tuesday, May 19, 2020, 07:56:08 a.m. EDT, HH PackRat <hhpackrat at gmail.com> wrote: 





On 5/19/20, Michael Dykman <mdykman at gmail.com> 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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