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 <[email protected]> Date: 9/5/18 4:04 PM (GMT-05:00) To: J-programming forum <[email protected]> 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 < [email protected]> 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 < > [email protected]> 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
