Why isn't f tacit, but g is? f=: 13 :'(+/ .* (1|.y)% */)y' f 2 3 5 1.03333 f 3 : '(+/ .* (1|.y)% */)y' g=: 13 :'((+/ .* 1&|.)% */)y' g 2 3 5 1.03333 g (+/ .* 1&|.) % */
Linda -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Don Kelly Sent: Thursday, October 31, 2013 10:09 PM To: [email protected] Subject: Re: [Jprogramming] making this tacit I made an error (BIG GOOF)and gave a problem other than what I wanted so I sent you and Raul on a wild goose chase. Your (+/@(*/)@(,: 1&|.) % */) 2 3 5 and Raul's ((+/ .* 1&|.) % */) 2 3 5 Agree and are more material to study, Thanks Don On 30/10/2013 5:59 AM, Jan-Pieter Jacobs wrote: > I'd write it tacitly like this: > > (+/@(*/)@(,: 1&|.) % */) a b c > > This is mainly motivated by the fact that a * b + b* c + c*a can be > expressed as multiplying with a shifted version, then summing. > > Jan-Pieter > > > 2013/10/30 Raul Miller <[email protected]> > >> On Wed, Oct 30, 2013 at 2:51 AM, Don Kelly <[email protected]> wrote: >> >>> You are right but it is a bit of serendipity What I wanted is (a*b+ >>> b*c+c*a ) % c a b . >>> it doesn't matter how the pairs are formed in the numerator ac+ba+cb >>> is the same. >>> >> Like this? >> >> F=: +/ .* (</~i.3) +/ .* ] % */ >> >> That's probably awful for speed, but it does express the idea. >> >> Thanks, >> >> -- >> Raul >> --------------------------------------------------------------------- >> - For information about J forums see >> http://www.jsoftware.com/forums.htm >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
