Why do you want this? If it's efficiency, note that the size of the dense array */~N is typically less than the size of a linked list which only represents the products of unique combinations of pairs (if we assume that linked list pointer size is approximately the same size as a number), and also note that typical cpu cache implementation heavily favors regular operations.
If it's because you need unique values, you might consider using: ~.,*/N If it's for some other purpose, the topic might have inherent interest... Thanks, -- Raul On Mon, Jun 25, 2012 at 12:37 PM, David Vaughan <purpleblue...@gmail.com> wrote: > I'm looking for a verb to achieve the same thing as just the unique items > of */~ N, i.e. n0*(n0 ... nk) n1*(n1 ... nk) n2*(n2 ... nk) ... nk*nk. > > I can easily create the result, but I want to be able to calculate it more > efficiently, without having to do the multiplications that will ultimately > be redundant (which would be ~.,*/~ N). > > I'm not particularly good with folds and similar concepts, so I expect the > solution is relatively simple. Can anyone help? > > Many thanks. > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
