Now I see that you have shown the correct calculation in J using verb flip and conjunction dotcj. I used power in my formulation to emphasize the interleaving. But by doing so I may have computed all products first. Are you suggesting that not all products in the inner product are calculated first, but only as needed for the accumulation (+/)?
Also, I see that dotcj produces a dyadic hook in an explicit definition. Very slick. On Tue, Jun 9, 2009 at 2:17 PM, Brian Schott<[email protected]> wrote: > Thanks, Roger. So does the following computation reflect the order of > calculation in row-at-a-time g"_1 before the f/ (that's a J /) ? > > 10 100 1000 <@:*"_1 i.3 4 > +----------+---------------+---------------------+ > |0 10 20 30|400 500 600 700|8000 9000 10000 11000| > +----------+---------------+---------------------+ > > And does the following calculation reflect row-at-a-time inner product > with a sort of interleaving? > (+/@(2&{.),(2&}.))^:_]10 100 1000 (*"_1) i.3 4 > 8400 9510 10620 11730 > > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
