I see now that my confusion stems from my misuse of words. I should not have said 'error' or 'mistake'. My opinion was/is that the dictionary entry would be clearer if it used #$y instead. But I can see that a discussion on clarity would quickly turn into matters of personal taste and not be worthwhile. Anyway, thank you for your patience and quick responses, and an even bigger thanks for implementing and maintaining J.
On Sat, Oct 5, 2013 at 3:24 PM, Roger Hui <[email protected]> wrote: > The dictionary entry says: > > In general, if y is not an atom, x may be a list of length not more than > $$y , and if y is an atom, it is replaced by ((#x)$1)$y . Element k > produces (k{x){."(($$y)-k) y ; an infinite value is replaced by the length > of the corresponding axis. > > > The statement is correct, both formally (executes on a computer) and > informally, if it says $$y or #$y. If it is correct, then it is not a > mistake. It is not to say that # and $ are interchangeable in all > situations. > > > > > On Sat, Oct 5, 2013 at 6:13 PM, Ganesh Rapolu <[email protected]> wrote: > > > Brevity is not always conducive to understanding. I would be grateful if > > you gave an explanation > > as to why this flexibility in the rank of a length is not a mistake. > > > > > > On Sat, Oct 5, 2013 at 3:01 PM, Roger Hui <[email protected]> > > wrote: > > > > > If it is a mistake I'd correct it, but it's not a mistake. > > > > > > > > > On Sat, Oct 5, 2013 at 5:44 PM, Ganesh Rapolu <[email protected]> > > wrote: > > > > > > > I am having difficulty finding reasons other than tradition that a > > length > > > > should be allowed to be a list. > > > > > > > > badlength =. $ > > > > mean =. +/ % badlength > > > > $ mean"1 i. 5 5 > > > > 5 1 > > > > > > > > Of course, J already does the right thing by providing # . It might > be > > in > > > > the spirit of J to continue to correct mistakes made in APL by > > correcting > > > > the documentation for take. > > > > > > > > > > > > On Sat, Oct 5, 2013 at 2:19 PM, Roger Hui <[email protected] > > > > > > wrote: > > > > > > > > > It is traditional in APL (and APL-like) systems that a length is a > > list > > > > or > > > > > a scalar. > > > > > > > > > > > > > > > > > > > > On Sat, Oct 5, 2013 at 4:53 PM, Ganesh Rapolu <[email protected] > > > > > > wrote: > > > > > > > > > > > Although it is the case that for a verb v and integer k, v"k and > > v"(, > > > > k) > > > > > > are the same, it might be confusing if the length referred to in > > the > > > > > phrase > > > > > > 'x may be a list of length not more than $$y' is not a scalar. > > > > > > > > > > > > > > > > > > On Sat, Oct 5, 2013 at 1:36 PM, Roger Hui < > > [email protected] > > > > > > > > > > wrote: > > > > > > > > > > > > > Both $$y or #$y are correct in this case. > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Sat, Oct 5, 2013 at 4:14 PM, Ganesh Rapolu < > > [email protected] > > > > > > > > > > wrote: > > > > > > > > > > > > > > > In the last paragraph, $$y should be #$y. > > > > > > > > > > > > > > > ---------------------------------------------------------------------- > > > > > > > > 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 > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
