f=: 4 :',(-.@{. 0}])&.|: (-x)[\y'
3 f a
0 1 1 0 1 1 0 1 1 0 1 1 0 1 1 0 1 1 0 1 0
2 f 3 f a
1 1 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 1 0
R.E. Boss
> -----Oorspronkelijk bericht-----
> Van: Programming <[email protected]>
> Namens Skip Cave
> Verzonden: donderdag 16 januari 2020 07:30
> Aan: [email protected]
> Onderwerp: Re: [Jprogramming] Selective verb application
>
> Suppose I want to invert every 3rd binary bit, then every second bit where f
> is -. (selective not):
>
> ]a=.20#1
>
> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
>
> ]b=.3 f a
>
> 0 1 1 0 1 1 0 1 1 0 1 1 0 1 1 0 1 1 0 1
>
> ]c .2 f b
>
> 1 1 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1
>
>
> How to define f?
>
>
> Skip
>
>
>
>
>
> On Wed, Jan 15, 2020 at 8:30 PM Skip Cave <[email protected]>
> wrote:
>
> > How does one apply a monadic verb repetitively to every nth element of
> > a one1-dimentional array?
> >
> > For example:
> >
> > ]a=.i.20
> > 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
> > n=.3
> >
> > NB. Design u to increment every nth integer in a:
> >
> >
> > u=.??:<??
> > n u a
> > 1 1 2 4 4 5 7 7 8 10 10 11 13 13 14 16 16 17 19 19
> >
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
