As for efficiency, see the entry for 2 f/\y in http://www.jsoftware.com/help/dictionary/special.htm , with more details in:
http://www.jsoftware.com/help/release/infix2.htm http://www.jsoftware.com/help/release/infix2a.htm On Fri, Aug 14, 2015 at 7:40 AM, Roger Hui <[email protected]> wrote: > What you want is "infix": > > 2 <\ 3 1 4 1 5 9 > ┌───┬───┬───┬───┬───┐ > │3 1│1 4│4 1│1 5│5 9│ > └───┴───┴───┴───┴───┘ > 2 -/\ 3 1 4 1 5 9 > 2 _3 3 _4 _4 > > > > > On Fri, Aug 14, 2015 at 7:30 AM, Yoel Jacobsen <[email protected]> > wrote: > >> Lately, I find myself repeatedly comparing pairs in arrays. >> >> I usually do something like: >> >> d =: 3 : '-/"1 }. y ,. 0 , }: y' >> >> >> d i. 5 >> >> 1 1 1 1 >> >> >> It feels like I'm reinventing the wheel but I couldn't find a simpler way >> (and more efficient for large arrays) to apply u over each pair of v. >> >> >> Is there a better way? >> >> >> Yoel >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
