Only for this example.
I can construct other examples where ?@ and ?@: give different results.
Do you see why?
Thanks,
--
Raul
On Thu, Jul 7, 2016 at 9:35 AM, 'Pascal Jasmin' via Programming
<programm...@jsoftware.com> wrote:
> ? (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
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
