Втр, 27 Июл 2010, Alex Rufon писал(а):
> +-+-+-------------------------------------+
> |4|:|NB. indices-of-elements (IO=1) from y|
> | | |(_1 + x) { y |
> +-+-+-------------------------------------+
This equation is interesting. So when counting from the end.
the last item is A[0], the second last item is A[-1]
ie. index origin 0
whereas for J the last item is A[-1], second last is A[-2]
ie, index origin 1
To be more correct for human domain so that always use index origin 1
when counting both from the beginning and from the end, it can be
improved as
if. 0=x do. assert. 0
elseif. 0<x do. (_1+x){y
elseif. do. x{y
end.
How does APL interpret negative index for either index origin?
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regards,
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