Two ways: s=: (1e5 [EMAIL PROTECTED] 1e6) (1e5 [EMAIL PROTECTED] 1e9)} 1$. 1e9 $s 1000000000 (3!:1 s) 1!:2 <'\junk\foo' s -: 3!:2 (1!:1) <'\junk\foo' 1 (3!:1 ] 4$.s) 1!:2 <'\junk\ii' (3!:1 ] 5$.s) 1!:2 <'\junk\xx' s -: (3!:2 (1!:1) <'\junk\xx') (<"1 (3!:2) 1!:1 <'\junk\ii')} 1$.1e9 1
----- Original Message ----- From: "Philip A. Viton" <[EMAIL PROTECTED]> Date: Sunday, June 1, 2008 8:41 Subject: [Jprogramming] recreating a sparse array To: [email protected] > > Given a dense array mx, we can create a sparse version via $. > say > smx. Then we can extract the make-up of smx (what the dictionary > refers to as sh, a, e, i and x) using dyadic $. Suppose I store > these > elements in a jfile (to save space, for example). Is there an > easy > way to use them to reconstitute the sparse array? I know I can > do > this by writing my own verb, but I would have thought that the > language would have provided a way to do this; and I can't find it. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
