On Wed, Dec 21, 2011 at 5:43 PM, Marshall Lochbaum <mwlochb...@gmail.com> wrote: > A more obvious way is to use (c { b,.a) . The key is to realize that saying > (if c then a else b) is just selection: if c is 0, we pick b, and if c is > 1, we pick a. So we rephrase as (c { b,a), and J's implicit rank allows us > to do (c { b,.a) for vector c, a, and b.
No. I think you mean (c {"_1 b,.a). a=: 10 20 30 b=: 1 2 3 c=: 1 0 1 c} b,:a 10 2 30 c { b,.a 2 20 1 10 2 20 c {"_1 b,.a 10 2 30 -- Ambrus ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm