Task: write f explicitly. f=:(0 ,.~ 0 ,. 0 ,~ 0 , ])^:[ F=:4 :'(0 ,.~ 0 ,. 0 ,~ 0 , ])^:x y'
Now, if you have additional goals, those are doable, but they should probably also be stated. For example, if you wanted to get rid of the train, you might do that like this: F2=: 4 :0 3 :'(0,(0,.y,.0),0)'^:x y ) Obviously, though, there are other possibilities (including the one you posted). Thanks, -- Raul On Sun, May 5, 2019 at 2:50 PM David Lambert <[email protected]> wrote: > > Task: write f explicitly. > > f=:(0 ,.~ 0 ,. 0 ,~ 0 , ])^:[ > > We try substituting x and y for [ and ] . > > g=: 13 :'(0 ,.~ 0 ,. 0 ,~ 0 , y)^:x' > > 2 g i. 2 3 > |domain error: g > | (0,.~0,.0,~0,y) ^:x > > > We see failure with power. > We look up power in NuVoc > [x] u^:n y Fixed Power Conjunction > > Oh! ^: requires a non-noun on its left (u) and a noun y to the right (n). > j computes (0 ,.~ 0 ,. 0 ,~ 0 , y) as a noun, and sure enough, domain error. > > We might choose > > g=: 13 :'(0 ,.~ 0 ,. 0 ,~ 0 , ])^:x y' > > or > > frame=: 13 :'(0 ,.~ 0 ,. 0 ,~ 0 , y)' > h=: 13 :'frame^:x y' > > > > NB. successful tests, g and h match f. > > (i.8) (g -: f)"0 _ i. 2 3 > 1 1 1 1 1 1 1 1 > > (i.8) (h -: f)"0 _ i. 2 3 > 1 1 1 1 1 1 1 1 > > At least, that's how I did it, and I probably shouldn't show this version > > explicit_f =: dyad define > result =. y > for_repetition. i. x do. > a =. 0 , result > b =. a , 0 > c =. b ,. 0 > result =. 0 ,. c > end. > ) > > > Date: Sun, 5 May 2019 07:36:11 +0000 > > From: Linda Alvord<[email protected]> > > To:"[email protected]" <[email protected]> > > Subject: Re: [Jprogramming] ambivalent tacit verb with Self-Reference > > Message-ID: > > > > <byapr10mb37353d62a16c9d17d4e6dbe3b5...@byapr10mb3735.namprd10.prod.outlook.com> > > > > Content-Type: text/plain; charset="utf-8" > > > > Here's a simple function: > > > > f=:(0 ,.~ 0 ,. 0 ,~ 0 , ])^:[ > > > > 3 f i.3 4 > > 0 0 0 0 0 0 0 0 0 0 > > 0 0 0 0 0 0 0 0 0 0 > > 0 0 0 0 0 0 0 0 0 0 > > 0 0 0 0 1 2 3 0 0 0 > > 0 0 0 4 5 6 7 0 0 0 > > 0 0 0 8 9 10 11 0 0 0 > > 0 0 0 0 0 0 0 0 0 0 > > 0 0 0 0 0 0 0 0 0 0 > > 0 0 0 0 0 0 0 0 0 0 > > > > But, oddly, I can't define this function explicitly. > > > > Linda > > > > -----Or > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
