Depends on the verb. In the case >:, a=: i. 20 n=: 3 a + 0=n|i.#a 1 1 2 4 4 5 7 7 8 10 10 11 13 13 14 16 16 17 19 19
Basically apply the verb or the identity function, depending on 0=n|i.#a . On Wed, Jan 15, 2020 at 6:30 PM Skip Cave <s...@caveconsulting.com> 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