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


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For information about J forums see http://www.jsoftware.com/forums.htm
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For information about J forums see http://www.jsoftware.com/forums.htm

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