Try x I. y on a list x and a single atom y first. It's easier to understand that way.
----- Original Message ----- From: PackRat <[email protected]> Date: Sunday, April 17, 2011 22:55 Subject: [Jprogramming] Wanted: "interval index" explanation To: Programming forum <[email protected]> > I'm trying to understand some J code that uses the interval > index I. > primitive. As a newbie to some of the more "advanced" > primitives in J, > the DoJ's explanation is beyond me. Can someone please > clue me in on > what the purpose of I. is and how it works (in verbose, easy > English, > please)? I thought I'd do a little trial and error (you > know, what > if...?) with some data to see what the results of I. were. > But looking > at the results below, I just don't see or understand what's > going on. > I also don't know how these results would then be used as a > possible > next step. > > d=. 0 1 4 5 7 8 11 13 14 17 > e=. 2 3 6 7 10 13 14 > > d I. e > 2 2 4 4 6 7 8 > e I. d > 0 0 2 2 3 4 5 5 6 7 > > If you prefer other examples, that's fine, too--as long as they > clearly > show what I. is doing. Thanks in advance for any help with > understanding I. better! ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
