You might try : ~. (#~ -.@~:) 4 6 8 6 5 8 6 6 6 9
6 8 On Sun, Jan 14, 2018 at 1:09 PM, Skip Cave <[email protected]> wrote: > Nice! Thanks to Henery Rich & R.E. Boss. > > For me, I want to list the dups just once. So I made this "find duplicates > (and list them once)" verb: > > fdp=. ~.@(#~-.@~:) > > Works great! > > I had tried this: > > ~.a#~1<+/ e. a=. 4 6 8 6 5 8 6 6 6 9 > > 6 8 > > > But my scheme doesn't scale well. I get "out of memory" errors on large > lists, so it is very wasteful of space, and it is WAY slower. > > > a=. ?1000$5000 > > (/:~fdp a) -: (/:~ ~.a#~1<+/ e. a) > > 1 > > ts 'fdp a' > > 5.99449e_6 4224 > > ts '~.a#~1<+/ e. a' > > 0.00294153 1.07405e6 > > > > > Skip > > > > > > > Skip Cave > Cave Consulting LLC > > On Sun, Jan 14, 2018 at 10:44 AM, R.E. Boss <[email protected]> wrote: > > > (-.@~:)4 6 8 6 5 8 6 6 6 9 > > 0 0 0 1 0 1 1 1 1 0 > > > > > > R.E. Boss > > > > > > > -----Original Message----- > > > From: Programming [mailto:[email protected]] > > > On Behalf Of Skip Cave > > > Sent: zondag 14 januari 2018 17:34 > > > To: [email protected] > > > Subject: [Jprogramming] Finding duplicates > > > > > > I have a string of integers. How do I list just the duplicates in the > > string? > > > > > > Skip > > > ---------------------------------------------------------------------- > > > 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 > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
