? (2,y) $ 0 or u N v N
is more formally equivalent to
(2,y)?@:$ 0 or N u@:v N
but because ? is a rank 0 verb, ?@ and ?@: will always give the same result.
----- Original Message -----
From: Martin Kreuzer <i...@airkreuzer.com>
To: programm...@jsoftware.com
Sent: Thursday, July 7, 2016 8:37 AM
Subject: [Jprogramming] Use of (@) 'Atop'
Hi all -
Approximating Pi using the Monte Carlo method (circle enscribed in
unit square) came up with
pia=. 13 : '(4 * y %~ +/ 1 >: +/ *: <: +: ? (2,y) $ 0)'("0)
(pia 10^(4+i.3)) ,:(4+i.3)
3.1524 3.1438 3.14106
4 5 6
I then compared my version with the J verb at Rosetta Code and the
only difference I found was the use of 'Atop':
piMC=: monad define "0
4* y%~ +/ 1>: %: +/ *: <: +: (2,y) ?@$ 0
)
Q:
What is the advantage (in this particular case) of using 'Atop'..?
? (2,y) $ 0
vs
(2,y) ?@$ 0
Thanks
-M
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