That said, I should probably restate what I said about lists being the only documented form for using gerunds in primitives:
Consider: (2 2 $>:`-:`*:`])`:0&.> 2 4 6 +---+----+----+ |3 1| 5 2| 7 3| |4 2|16 4|36 6| +---+----+----+ (2 2 $>:`-:`*:`])`:0] 2 4 6 3 5 7 1 2 3 4 16 36 2 4 6 This is perfectly reasonable behavior, But the dictionary currently says: http://www.jsoftware.com/help/dictionary/d612.htm m `: 0 Append Appends the results of the individual verbs. In fact, the implementation is structure preserving. The hypothetical "appends" happen in a way which would build the original frame structure of the verb arguments. Thus, there are "zero appends" when the left side of `: is an atomic representation with an empty shape, and the shape of the left side of `: appears in the shape of the result: $({.>:`'')`:0] 2 4 6 3 $(>:`'')`:0] 2 4 6 1 3 Thus, getting back to the original {. -- it's not that the shape of the gerund -- the shape of the noun containing the atomic representation -- carries no information. It's that that shape information is independent of the underlying atomic representation. Put differently, these are work-alikes: 1 :'{.u`''''' 1 :'5!:2<''u''' (or they seem to be -- I think they should be and I can't find any exceptions). -- Raul -- Raul On Sat, Feb 18, 2012 at 2:06 PM, Raul Miller <rauldmil...@gmail.com> wrote: > Or, for something written by Ken Iverson rather than Roger Stokes: > > http://www.jsoftware.com/help/dictionary/d610.htm > > -- > Raul > > On Sat, Feb 18, 2012 at 2:04 PM, Raul Miller <rauldmil...@gmail.com> wrote: >> Here's an example of a definition for gerund: >> >> http://www.jsoftware.com/docs/help701/learning/14.htm >> >> You might argue that the definition is informal -- like most of J -- >> but I do not think it's fair to say that they are not defined >> anywhere. >> >> -- >> Raul >> >> On Sat, Feb 18, 2012 at 1:10 PM, Dan Bron <j...@bron.us> wrote: >>> I'm not sure gerunds are defined anywhere. >>> >>> But if they were, the phrasing might be "arrays of atomic representations", >>> where the "atomic representation" characteristic is the most salient, and >>> "array" has the normal meaning (and perhaps the usual question of whether a >>> scalar is an array?). >>> >>> We often (informally) think of gerunds as vectors, because we compose them >>> with ` whose product is defined to be vector, and consume them with e.g. @. >>> whose (left input) is most useful when vector. But that's no reason to >>> define gerunds as vectors, any more than to define selections as vectors, >>> because we compose them with , , and consume them with e.g. { whose (left >>> input) is frequently vector. Or saying 'string' is a string but 's' is not. >>> >>> Of course, in some contexts, 's' is not considered a string. So perhaps >>> you are suggesting that "gerunds are are arrays of atomic representations, >>> where the shape of the array has meaning"? If so, this is an interesting >>> digression, which I'm happy to discuss, but perhaps we should move it to a >>> different thread. >>> >>> The original question was not concerned with gerunds, and I doubt having >>> the atomic representation of f@g (vector or scalar) in the corner of the >>> result table would be satisfying. What was wanted was the string >>> representation (which is produced using 5!:5, which operates on scalars, so >>> shape doesn't have meaning to it, and neither does atomic representation). >>> >>> Anyway, when present the promise of J to newcomers, we need to take care >>> not obscure the pitfalls. The literal Jenie (dJinni?) who delivers exactly >>> what was asked for is rarely the hero of folklore. >>> >>> -Dan >>> >>> PS: If we wish to continue the digression, it might be better to start >>> with the links below, better starting point would be wh >>> >>> Here's a couple places where I've attempted to capture the meaning of >>> "gerund" >>> >>> Sidebar in NuVoc definition of ` : >>> http://jsoftware.com/jwiki/Vocabulary/backtick#sidebar.3Agerunds >>> >>> As a necessary premise in the definition of a modifier utility: >>> www.jsoftware.com/jwiki/DanBron/Snippets/DOOG#definition >>> >>> Please excuse typos; composed on a handheld device. >>> >>> -----Original Message----- >>> From: Raul Miller <rauldmil...@gmail.com> >>> Sender: programming-boun...@jsoftware.com >>> Date: Sat, 18 Feb 2012 11:52:13 >>> To: Programming forum<programming@jsoftware.com> >>> Reply-To: Programming forum <programming@jsoftware.com> >>> Subject: Re: [Jprogramming] Verb display in function tables >>> >>> Ok... >>> >>> ...except that gerunds are defined as vectors. >>> >>> Conceptually speaking, if it's a scalar, or a matrix, it's something >>> different. It would still be gerund-like, in character (we can >>> trivially extract gerunds from it), but if we try using such things >>> with primitives that handle gerunds, we are getting into undocumented >>> territory. >>> >>> -- >>> Raul >>> >>> On Sat, Feb 18, 2012 at 11:18 AM, Dan Bron <j...@bron.us> wrote: >>>> That makes sense. >>>> >>>> My personal impression was that the original vector-ness was an >>>> (unintentional) side-effect of the method used to remove the trailing atom >>>> (select-all-but-last as opposed to select-first). >>>> >>>> The proposed scalar should be a transparent replacement for the original >>>> vector, whose shape wasn't serving a specific purpose (normally, in J, >>>> shape carries meaning, and where it doesn't it is misleading: at best >>>> superfluous, but often pernicious). >>>> >>>> -Dan >>>> >>>> >>>> Please excuse typos; composed on a handheld device. >>>> >>>> -----Original Message----- >>>> From: Raul Miller <rauldmil...@gmail.com> >>>> Sender: programming-boun...@jsoftware.com >>>> Date: Sat, 18 Feb 2012 10:41:56 >>>> To: Programming forum<programming@jsoftware.com> >>>> Reply-To: Programming forum <programming@jsoftware.com> >>>> Subject: Re: [Jprogramming] Verb display in function tables >>>> >>>> I often do that myself, but in this case, the original phrase was also >>>> generating a 1 element vector, so I decided that a 1-element vector >>>> was an appropriate result. >>>> >>>> -- >>>> Raul >>>> >>>> On Sat, Feb 18, 2012 at 9:48 AM, Dan Bron <j...@bron.us> wrote: >>>>> Because in many contexts, a scalar is more convenient than a 1-element >>>>> vector, I make a habit of tacking on a {. as in {.u`'' . >>>>> >>>>> -Dan >>>>> >>>>> >>>>> On Feb 18, 2012, at 9:32 AM, Raul Miller <rauldmil...@gmail.com> wrote: >>>>> >>>>>> I would use u`'' >>>>>> >>>>>> avg 1 :'u`''''' >>>>>> +---+ >>>>>> |avg| >>>>>> +---+ >>>>>> avg >>>>>> |value error: avg >>>>>> >>>>>> -- >>>>>> Raul >>>>>> >>>>>> >>>>>> On Fri, Feb 17, 2012 at 1:57 PM, Edward Mokurai Cherlin >>>>>> <moku...@sugarlabs.org> wrote: >>>>>>> I had thought that I would not be able to get a program to show the >>>>>>> definition of a function given its name, but I found a kludge for the >>>>>>> purpose using tie. Now I would like to know whether somebody has a >>>>>>> direct solution. My application for this capability is a defined >>>>>>> adverb for producing function tables. >>>>>>> >>>>>>> t=.1 :(':';'2 2$(>1 0#u`u);y;(,.x);x u/ y') >>>>>>> l +t l=.i.5 >>>>>>> ┌─┬─────────┐ >>>>>>> │+│0 1 2 3 4│ >>>>>>> ├─┼─────────┤ >>>>>>> │0│0 1 2 3 4│ >>>>>>> │1│1 2 3 4 5│ >>>>>>> │2│2 3 4 5 6│ >>>>>>> │3│3 4 5 6 7│ >>>>>>> │4│4 5 6 7 8│ >>>>>>> └─┴─────────┘ >>>>>>> >>>>>>> The question then is whether somebody knows a less ugly way to display >>>>>>> the value of u in executing this adverb than >1 0#u`u or >0{u`u . >>>>>>> >>>>>>> -- >>>>>>> Edward Mokurai (默雷/धर्ममेघशब्दगर्ज/دھرممیگھشبدگر ج) Cherlin >>>>>>> Silent Thunder is my name, and Children are my nation. >>>>>>> The Cosmos is my dwelling place, the Truth my destination. >>>>>>> http://wiki.sugarlabs.org/go/Replacing_Textbooks >>>>>>> ---------------------------------------------------------------------- >>>>>>> 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 >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
