http://www.mathmarauder.com/archives/178
That function F, written in tacit J, might look like this: F=: ([: +/@:- [: */"1@:- [ ^/ (^"1 #:@i.@^~&2@#)@]) q:@] Or, in explicit J, might look like this: F=:dyad define t=. q:y +/-*/"1-x^/t^"1#:i.2^#t ) As the explicit form is more compact than the tacit form, I think I prefer it for this case. Also, in this case, I think I prefer having an explicit variable representing the factors (rather than simply relying on a hook to get the needed two copies of them). But I think composing both can be a worthwhile exercise. Thanks, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
