Continuing with 1D and allowing for negative shift I have the following Still no 2D version, though.
s=: adverb define
:
if. m >: 0
do.
s=. y,~ m {.x
f=. x, (1-m){.y
else.
s=. y, (m-1){.x
f=. x,~ (-m){.y
end.
f,:s
)
mean=: +/ % #
mean (i. 5) _1 s 2* i. 4
0 1 2.5 4 3 4
--
(B=)
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
