2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 +/2 3 5 7 1 1 1 1 2 2 3 3 4 4 4 ([: +/@:({."1) 10 #.^:_1 p:@:i.) 15 26 (+/@:(<.@:% >:@:<.&.(10&^.))@:p:@:i.) 15 0
2010/11/16 Dan Bron <j...@bron.us> > Oh, sorry, thinko: you wanted the first digit, and I gave you the last > digit. So: > > [: +/@:({."1) 10 #.^:_1 p:@:i. > > Or you could do something along the lines of: > > +/@:(<.@:% >:@:<.&.(10&^.))@:p:@:i. > > Of course, I haven't tested any of this, but the fact that I can respond in > such a manner from my blackberry, on my commute, without the aid of a J > interpreter, may tell you something about tacit programming. > > In other words: using tacit code, we are communicating. > > -Dan > > PS: Of course, we could also communicate using explicit code or Fortran or > even standard math notation; it would just be harder to read & write under > these constraints. > > For example, tacit's concise notation allows the reader to quickly spot the > bug in my initial suggestion (last digit vs first), and similarly allows the > writer to concisely express abstract concepts like &.(10&^.) . > > (And elegantly, if I'm allowed to editorialize) > > > Please excuse typos; composed on a handheld device. > > -----Original Message----- > From: Björn Helgason <gos...@gmail.com> > Sender: programming-boun...@jsoftware.com > Date: Tue, 16 Nov 2010 12:38:39 > To: Programming forum<programming@jsoftware.com> > Reply-To: Programming forum <programming@jsoftware.com> > Subject: Re: [Jprogramming] tacit programming > > That is not giving the correct answer 43 for the first 15 primes > > (10 +/@:#: p:@:i.) 15 > 68 > ([: +/ [: > [: ".&.> [: [ [: {.&.> [: [ [: ":&.>@p: i.) 15 > 43 > > > > 2010/11/16 Dan Bron <j...@bron.us> > > > Björn wrote: > > > The objective is to get the first number from a list of primes. > > > > > > Is there a better way of getting the first number from a list of > numbers > > > putting them each in a box than making it first a character and the > > taking > > > the first of each element making it a number and summing up the > resulting > > > list? > > > > I've always preferred to ask for digits directly (numerically), rather > than > > projecting into the string domain and returning to the numeric domain: > > > > 10 +/@:#: p:@:i. > > > > -Dan > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > Björn Helgason, Verkfræðingur > Fornustekkum II > 781 Hornafirði, > t-póst: gos...@gmail.com > gsm: +3546985532 > sími: +3544781286 > http://groups.google.com/group/J-Programming > > > Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans > > góður kennari getur stigið á tær án þess að glansinn fari af skónum > /|_ .-----------------------------------. > ,' .\ / | Með léttri lund verður | > ,--' _,' | Dagurinn í dag | > / / | Enn betri en gærdagurinn | > ( -. | `-----------------------------------' > | ) | (\_ _/) > (`-. '--.) (='.'=) ♖♘♗♕♔♙ > `. )----' (")_(") ☃☠ > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Björn Helgason, Verkfræðingur Fornustekkum II 781 Hornafirði, t-póst: gos...@gmail.com gsm: +3546985532 sími: +3544781286 http://groups.google.com/group/J-Programming Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans góður kennari getur stigið á tær án þess að glansinn fari af skónum /|_ .-----------------------------------. ,' .\ / | Með léttri lund verður | ,--' _,' | Dagurinn í dag | / / | Enn betri en gærdagurinn | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) ♖♘♗♕♔♙ `. )----' (")_(") ☃☠ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm