Don, try
(+/ *:) 0 1 2 3 4
and look up II. F. Trains in the Dictionary (in J press F1 then click on Dic).
For composition you can use [: +/ *: as in
([: +/ *:) 3 4
25
where [: is a true innovation, an "identity element" that reduces reduces a
"tree"
f
/ \
[: g
to
f
\
g
Kip Murray
2009/4/26 Don Watson <[email protected]>
1) Use %: for square root.
2) Use *: for square.
and so on.
+/ *: 2 6 8 9
but have to write:
sumsq =: +/ @: *:
Why is that @: necessary?
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
