Hmmm. When you say "atoms", did you mean individual elements of a an array?
Because I tried it out with a simple sum across: i. 3 5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A normal sum across would give me the sum of the columns +/ i. 3 5 15 18 21 24 27 Doing it with rank 0 would not compute. I assumed that the verb was applied on each element as you've explained +/ "0 i. 3 5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Using rank 1 would actually give me a total of each rows +/ "1 i. 3 5 10 35 60 This is consistent with your explanation. Still, I am a bit bewildered on when to use rank 0. What clues or hints or a guideline should remind me that it's the time to use it? Rank 1 is very easy because I've easily associated it with the concept that it's like transposing. Example: +/ "1 i. 3 5 10 35 60 +/ |: i. 3 5 10 35 60 It never even occurred to me that my problem could use it. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Oleg Kobchenko Sent: Tuesday, July 01, 2008 4:47 PM To: Programming forum Subject: RE: [Jprogramming] Formatting then Boxing a vector It's actually the other way around: rank-0 is atoms or columns of matrix, and rank-1 is vectors or rows of matrix. The reason you might have thought of rank-1 as columns is because it makes verb seem to operate on cells collectively aligned into columns, as in {."1 A will return first column, whereas it actually returns list of first cell in each row--so it applies the verb to rows. This confusion may have resulted from APL axes. See J Forums for example, http://www.jsoftware.com/pipermail/programming/2006-June/002509.html --- On Tue, 7/1/08, Alex Rufon <[EMAIL PROTECTED]> wrote: most likely I misunderstand it. I only use rank 1 when I try to apply a verb on the column level of a two dimension matrix. I assume (from what I've read so far) that rank zero is the rows of a two dimension matrix and is assumed that its there and is omitted. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
