I'm not sure I understand the concept of dynamic execution, but I found a tacit expression which helped me understand the result.
g=: 13 :'((+/ .* 1&|.)% */)y' g 2 3 5 1.03333 h=: 13 :'(y+/ .* 1|.y)% */y' h 2 3 5 1.03333 g (+/ .* 1&|.) % */ h (] +/ .* 1 |. ]) % */ h in not quite as nice as g, but I found it helpful. Linda -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dan Bronb Sent: Friday, November 01, 2013 8:15 AM To: [email protected] Subject: Re: [Jprogramming] making this tacit Because with f, you're asking that a NVV train be created dynamically based on its argument: that is, you're changing syntax during execution. There is no tacit way to express that - dynamic execution of code is the definition of explicit. -Dan Please excuse typos; composed on a handheld device. > On Nov 1, 2013, at 4:30 AM, "Linda Alvord" <[email protected]> wrote: > > 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 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
