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.That said, (c} b,:a) is faster, and uses less memory by not actually computing b,:a . So it's a better choice. Marshall On Wed, Dec 21, 2011 at 10:26 AM, Brian Schott <schott.br...@gmail.com>wrote: > One way is the following. > > c}b,:a > 10 2 30 > > > -- > (B=) > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
