It seems Roger is a mortal; s=: ?4 4$2 (4&$.)^:_1 (4 $. s) |domain error (4&$.)^:_1(4 $.s)
...or is my copy of J too old? ------------------------------------------------------------------------ |\/| Randy A MacDonald | APL: If you can say it, it's done.. (ram) |/\| [EMAIL PROTECTED] | |\ | | The only real problem with APL is that BSc(Math) UNBF'83 | it is "still ahead of its time." Sapere Aude | - Morten Kromberg Natural Born APL'er | Demo website: http://156.34.82.188/ -----------------------------------------------------(INTP)----{ gnat }- ----- Original Message ----- From: "June Kim" <[EMAIL PROTECTED]> To: "Programming forum" <[email protected]> Sent: Saturday, February 03, 2007 8:16 AM Subject: [Jprogramming] Spare Matrix from Index Matrix > ]m=: 1 0 0, 0 1 0,: 0 1 0 > 1 0 0 > 0 1 0 > 0 1 0 > ]i=:4$.$. m > 0 0 > 1 1 > 2 1 > ]m2=:1 (<"1 i)} 3 3$0 > 1 0 0 > 0 1 0 > 0 1 0 > ]s=:$.m2 > 0 0 │ 1 > 1 1 │ 1 > 2 1 │ 1 > > Can I get s from i without going through the dense matrix form? > ---------------------------------------------------------------------------- ---- > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
