... this thread popped up over breakfast, so to speak. Playing with Roger’s solution, I noticed this variant which happens to solve a more specialised requirement, to indicate doubletons only: ~:~:~:&.|. as in (~:~:~:&.|.)t 1 1 0 1 1 1 0 0 0 1 0 ... so the 2, which occurs 3 times is not flagged.
I post it only because it’s an excuse for an (apparent) train of 3 identical verbs; yes, I know that’s not quite true, but it looks good! Happy New Year, Mike Sent from my iPad > On 30 Dec 2018, at 00:43, Roger Hui <[email protected]> wrote: > > t > 3 5 4 2 3 5 6 2 9 2 8 > (~: *: ~:&.|.) t > 1 1 0 1 1 1 0 1 0 1 0 > > > >> On Sat, Dec 29, 2018 at 4:33 PM Jimmy Gauvin <[email protected]> wrote: >> >> Hi, >> >> is there a better way tag duplicates in a list than the following (which >> smells of overkill) : >> >> t=:3 5 4 2 3 5 6 2 9 2 8 >> t e. (~.t) #~ 1~: #/.~t >> 1 1 0 1 1 1 0 1 0 1 0 >> >> Thanks, >> >> Jimmy >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
