While I am comparing the learning of J to the learning of english: Do we have grammar school students learn english by asking them to only use [insert grammatical structure here]? Why or why not?
If so, how well does that work? If not, what do we do instead? Thanks, -- Raul On Sat, Feb 2, 2013 at 2:13 AM, Linda Alvord <[email protected]> wrote: > Also, this has only forks: > > > > 5!:4 <'t1' > > ┌─ 2 > ┌───┼─ {. > │ └─ [ > ├─ $ > │ ┌─ [: > ──┤ ┌────┼─ ; > │ │ └─ ] > │ ├─ /: > └───┤ ┌─ [: > │ ├─ ; > └────┤ ┌─ [: > │ ├─ /. ─── < > └────┤ > │ ┌─ [: > └──────┼─ i. > └─ [ > > > > This has both forks and hooks: > > > > 5!:4 <'t2' > > ┌─ 2 > ┌───┼─ {. > │ └─ [ > ├─ $ > ──┤ ┌─ ] > │ │ ┌─ /: > │ ├─ & ─┴─ ; > └───┤ > │ ┌─ [: > │ ├─ /. ─── < > └─────┤ > │ ┌─ [: > └──────┼─ i. > └─ [ > > > > Linda > > > > -----Original Message----- > From: [email protected] [mailto:programming- > [email protected]] On Behalf Of Linda Alvord > Sent: Saturday, February 02, 2013 2:00 AM > To: [email protected] > Subject: Re: [Jprogramming] inverse oblique > > > > I remember fondly how Ken loved to read the unabridged dictionary. Richness > of the language and the derivations of the words was a joyous experience > for him. The J language has this same richness. > > > > For students coming to the language with years of mathematical background > in abstract algebra, calculus, differential equations and the like, they > are ready t o jump easily to abstract combinations. > > > > I keep thinking in terms of the long time it takes high school students to > master functional notation like f(x) and g(x). > > > > > > To get from t1 to t2 requires and "idiom" x u&v y ↔ (v x) u (v y) > > > > t1=: 13 :'(2{.x)$(;y)/:;</.i.x' > > t2=: 13 :'(2{.x)$y/:&;</.i.x' > > > > So although t1 is longer than t2, t2 is more condensed and compex. This > is why I say easier: > > > > t1 > > (2 {. [) $ ([: ; ]) /: [: ; [: </. [: i. [ > > t2 > > (2 {. [) $ ] /:&; [: </. [: i. [ > > > > The condensed spacing of /:&; gives away the increased complexity of the > second tacit version. > > > > My guess is that you would spend less time reading the dictionary to master > > t1 than t2. > > > > Linda > > > > -----Original Message----- wo > > From: <mailto:[email protected]> programming- > [email protected] [mailto:programming- > <mailto:[email protected]> [email protected]] On > Behalf Of Raul Miller > > Sent: Friday, February 01, 2013 9:20 AM > > To: <mailto:[email protected]> [email protected] > > Subject: Re: [Jprogramming] inverse oblique > > > > How do you define "easier"? > > > > In my opinion, it's easier to go from simple (fewer tokens) to complex > (more tokens), but also someone has to write the code to do the > transformation and until that's been done even this concept of "easier" can > be indistinguishable from "can't be done". > > > > -- > > Raul > > > > On Fri, Feb 1, 2013 at 5:05 AM, Linda Alvord < > <mailto:[email protected]> [email protected]> > > wrote: > >> If t1 is easy tacit and t2 is advanced tacit, wouldn't it be easier > >> for J to figure t2 from t1 than it is for me? > >> > >> t=: 5 7 2 ?@$ 1e6 > >> s=: $t > >> x=: </.t > >> t1=: 13 :'(2{.x)$(;y)/:;</.i.x' > >> t-:s f x > >> 1 > >> t2=: 13 :'(2{.x)$y/:&;</.i.x' > >> t-:s g x > >> 1 > >> t1 > >> (2 {. [) $ ([: ; ]) /: [: ; [: </. [: i. [ > >> t2 > >> (2 {. [) $ ] /:&; [: </. [: i. [ > >> > >> Or is that just wishful thinking? > >> > >> Linda > >> > >> > >> -----Original Message----- > >> From: <mailto:[email protected]> programming- > [email protected] > >> [ <mailto:[email protected]> mailto:programming- > [email protected]] On Behalf Of Roger > >> Hui > >> Sent: Thursday, January 31, 2013 1:49 PM > >> To: Programming forum > >> Subject: Re: [Jprogramming] inverse oblique > >> > >> t -: (2{.s) $ x /:&; </.i.s > >> 1 > >> > >> > >> > >> On Thu, Jan 31, 2013 at 10:47 AM, Roger Hui > >> < <mailto:[email protected]> [email protected]>wrote: > >> > >>> t=: 5 7 2 ?@$ 1e6 > >>> s=: $t > >>> x=: </.t > >>> > >>> t -: (2{.s) $ (;x)/:;</.i.s > >>> 1 > >>> > >>> > >>> > >>> On Thu, Jan 31, 2013 at 10:28 AM, Raul Miller > >> < <mailto:[email protected]> [email protected]>wrote: > >>> > >>>> Let's start with an arbitrary array: > >>>> > >>>> A=: i. 2 3 > >>>> > >>>> We can box oblique lines from this array: > >>>> > >>>> </. A > >>>> +-+---+---+-+ > >>>> |0|1 3|2 4|5| > >>>> +-+---+---+-+ > >>>> > >>>> However, the interpreter does not currently provide us with an > >>>> inverse for this operation: > >>>> > >>>> </.inv </. A > >>>> |domain error > >>>> > >>>> One problem is that you cannot uniquely determine the first two > >>>> elements of the shape of the original array by inspecting </.'s > >>>> result: > >>>> > >>>> (</. 5 7$0) -: </.7 5$0 > >>>> 1 > >>>> > >>>> If its shape is provided, how might we reconstruct the original array? > >>>> > >>>> [For the sake of simple code, it's ok to focus on numeric, rank 2 > >>>> arrays.] > >>>> > >>>> -- > >>>> Raul > >>>> -------------------------------------------------------------------- > >>>> - > >>>> - For information about J forums see > >>>> <http://www.jsoftware.com/forums.htm> > http://www.jsoftware.com/forums.htm > >>>> > >>> > >>> > >> ---------------------------------------------------------------------- > >> For information about J forums see <http://www.jsoftware.com/forums.htm> > http://www.jsoftware.com/forums.htm > >> > >> ---------------------------------------------------------------------- > >> For information about J forums see <http://www.jsoftware.com/forums.htm> > http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see <http://www.jsoftware.com/forums.htm> > http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > For information about J forums see <http://www.jsoftware.com/forums.htm> > 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
