Hi Linda - I'll keep my eyes open for that book but I've gotten a good reference in the meantime - http://www.jsoftware.com/help/jforc/loopless_code_i_verbs_have_r.htm#_Toc191734331 - that gives me something to anchor the basic premise of the Wikipedia article.
Thanks, Devon On Fri, Sep 14, 2018 at 10:44 AM lindaalvord <lindaalv...@verizon.net> wrote: > Oops this belongs here. . . > Hi Devon, Tama and I just flew up toNYC. I had time to take my eyes off > tacit and found this. There was a white book about education for APL. I > can,t remember the name. Ken and three or four teachers put it together one > summer at IBM. It might have something.Linda > > > > > > Sent from my Verizon, Samsung Galaxy smartphone > -------- Original message --------From: Devon McCormick < > devon...@gmail.com> Date: 9/5/18 4:04 PM (GMT-05:00) To: J-programming > forum <programm...@jsoftware.com> Subject: Re: [Jprogramming] Using rank > to avoid looping - reference? > Thanks for all the responses. > > Raul: you are right as array programming without rank also lets you avoid > loops; rank refines how one slices an array. > > What I'm looking for are works I can cite on the Wikipedia page. As it > stands, it's too free-form and and too original which is not what the > Wikipedia guidelines specify. I will resort to things like the J site or a > Mathematica help page but I'm concerned about the potential drawbacks of > citing a web-page that may change or disappear as opposed to a published > work. Also, now that I look at the Mathematica page for "map", it does not > seem to be a good fit as their map looks very vectorish, not generally > array-oriented, so it's not clear that rank applies. I may have to remove > these claims unless I find a more apt source. > > Pascal: thanks for pointing out the problem with /. I'll fix that. > > Part of the problem is that most other languages' references to "array" > really mean "numeric vector", at least in my experience. > > > > On Wed, Sep 5, 2018 at 2:52 PM 'Pascal Jasmin' via Programming < > programm...@jsoftware.com> wrote: > > > the wikipage mislabels the / operator as map as well (it is in fact a > > reduce operator) > > > > The functional map function replaces a "for each" loop. Rank is very > > closely tied to this, with the addition of specifying the > size/slice/scope > > of the "each element" group > > > > > > On Wednesday, September 5, 2018, 1:56:33 p.m. EDT, Cliff Reiter < > > reit...@lafayette.edu> wrote: > > > > > > > > > > > > From Mathematica help: > > > > Map (Built-in Symbol) > > Map[f, expr] or f /@ expr applies f to each element on the first level > > in expr. Map[f, expr, levelspec] applies f to parts of expr specified by > > levelspec. Map[f] represents\[Ellipsis] > > > > > > On 9/5/2018 10:58 AM, devonmcc wrote: > > > I am trying to bring the Wikipedia page on "rank (J programming > > language)" into compliance with the guidelines by inserting more inline > > references but am stumped by that page's initial assertion that rank is a > > generalization of looping, as well as the subsequent claims about rank > > generalizing "map" and "maplist". > > > Searches for a word like "rank" bring up many irrelevant hits even when > > included with programming-specific terms. Also, the best reference I > have > > found so far - www.ccs.neu.edu/home/jrslepak/typed-j.pdf - uses language > > like "...a form of rank...which renders much of a program's control > > structure implicit by lifting base operators to higher-dimensional array > > structures." I will have to include this in the references to use it but > > was hoping to find an older document, preferably one already in the > > references, but have been stymied by the lack of explicit reference to > > avoiding loops by using rank because it seems so obvious that it is only > > implied. > > > In any case, a reference to the assertions about "map" and such would > > also be appreciated. > > > Thanks, > > > Devon > > > Sent from my Verizon, Samsung Galaxy smartphone > > > ---------------------------------------------------------------------- > > > 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 > ---------------------------------------------------------------------- > 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
