Not to mention the mnemonic value of calling this use of the "at" sign "atop".
On Mon, May 6, 2019 at 10:38 PM 'Rob Hodgkinson' via Programming < programm...@jsoftware.com> wrote: > Further to this, I admit when following up on Thomas’ original question, I > found it most helpful that Ken’s “Arithmetic” paper did actually name the > operation as “atop” which I could google/search across subsequent papers > and the current J Vocabulary to associate it correctly and found I could > rely on that name. Ken was always very well known for his precise naming > conventions to convey it’s actual meaning. > > Also noted by The American Heritage Dictionary was his favourite > reference, from which he could draw on the roots of all words for correct > nomenclature. > > Perhaps “atop” contributed something more specific to the dyadic > compositions … I’d be inclined to let sleeping dogs lie here as preserving > it does allow cross reference of his past texts to current implementation. > > …/Rob > > > On 6 May 2019, at 11:55 pm, Roger Hui <rogerhui.can...@gmail.com> wrote: > > > > In the monadic case, there aren't many choices regarding function > > composition: > > > > u@v y ←→ u v y > > u&v y ←→ u v y > > > > But in the dyadic case, some very different choices are possible: > > > > x u@v y ←→ u (x v y) > > x u&v y ←→ (v x) u (v y) > > > > So which one of these @ or &, should be named "of" or "on" or "after"? > > > > That's one of Iverson's key contributions, compositions involving dyadic > > functions. > > > > > > > > On Mon, May 6, 2019 at 5:42 AM Henry Rich <henryhr...@gmail.com> wrote: > > > >> Wikipedia (from Function Composition): > >> > >> /g/ ∘ /f/is read as "/g/circle/f/", "/g/round/f/", "/g/about/f/", > >> "/g/composed with/f/", "/g/after/f/", "/g/following/f/", "/g/of/f/", or > >> "/g/on/f/". > >> > >> I would say 'on', but I don't think that's much better than the others, > >> including 'atop'. Maybe 'after' would be easiest for newcomers. > >> > >> Henry Rich > >> > >> > >> On 5/6/2019 8:38 AM, Brian Schott wrote: > >>> Piet, > >>> I cannot answer your question, but I do not like "atop" either. > >>> To me the rewording would be as follows, though: (your line first, my > >> line > >>> second) notice the missing "of". > >>> 'It seems more natural to say (u@v y) is "u of v of y” rather than > 'u > >>> atop v of y.”' > >>> 'It seems more natural to say (u@v y) is "u of v y” rather than > 'u > >>> atop v of y.”' > >>> ---------------------------------------------------------------------- > >>> For information about J forums see http://www.jsoftware.com/forums.htm > >> > >> > >> > >> --- > >> This email has been checked for viruses by AVG. > >> https://www.avg.com > >> ---------------------------------------------------------------------- > >> 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 > -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
