I added the display step. I also modified the index in a, changed them
from y to y-1 since J has zero as index origin.
I guess 99% of the time is spent in the r=: r,a step. /Erling
Den 2017-10-30 kl. 15:43, skrev Raul Miller:
Hmm... you're right, that deals with some cases quite a bit better than mine.
I can dip into most of them like this:
parRDM=:4 :0
select. x
case.1 do.
,.< i.y
case.2 do.
((y#2)#:"1 0 }.i.2^y-1) </."1 i.y
case.y do.
,:<"0 i.y
case.do.
x (1+y-x) P y
end.
)
... keeping the definition of P (and combine) from
http://jsoftware.com/pipermail/programming/2017-October/049423.html
That said, parRuskey still is more efficient for the case where x =
y-2 and and y>3 and that's worth some thought.
Generally speaking, parRuskey has an advantage of working with
partition id rather than partition contents, until the very last step.
That's a clean performance advantage (no boxed arrays for most of the
work). But ... still needs thought.
Thanks,
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
