Wow. How is this exmpalined?

Whereas

   Q=: _2+?1e6$5
   (+/\ -: +/\.&.|.) Q
1
   ts '+/\ Q'
0.00822809 4.19546e6
   ts '+/\.&.|. Q'
0.0244686 8.39014e6


--- Jose Mario Quintana <[EMAIL PROTECTED]> wrote:

> 
>    T=. ?1000$9
>    st'(([^:(0=]))/\) T' 
> 19136 2.13611842
>    st'(([^:(0=]))~/\. &. |.) T' 
> 11200 0.00382534652
> 
>    ((([^:(0=]))/\)  -: (([^:(0=]))~/\. &. |.)) T 
> 1
> 
> 
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:programming-
> > [EMAIL PROTECTED] On Behalf Of Oleg Kobchenko
> > Sent: Wednesday, December 13, 2006 12:38 PM
> > To: Programming forum
> > Subject: Re: [Jprogramming] What a drag
> > 
> > That was a result of posing a question
> > "How would a fast C code look like?" and
> > then translated to J.
> > 
> > Unfortunately, though it looks nice, it does not
> > work fast in J. Whereas >./\ special coded,
> > ([^:(0=]))/\ is not, although it is single scan tacit.
> > 
> > As a result, more cumbersome multiscan algorithms
> > perform faster.
> > 
> > 
> > --- ramacd <[EMAIL PROTECTED]> wrote:
> > 
> > > That is truly beautiful.
> > >
> > >
> > > ----- Original Message -----
> > > From: "Oleg Kobchenko" <[EMAIL PROTECTED]>
> > > To: "Programming forum" <[email protected]>
> > > Sent: Tuesday, December 12, 2006 4:31 AM
> > > Subject: RE: [Jprogramming] What a drag
> > >
> > >
> > > > More generally
> > > >
> > > >    ([^:(0=]))/\ 5 4 0 0 5 0 3 0 0 0 7
> > > > 5 4 4 4 5 5 3 3 3 3 7
> > > >
> > > >
> > > > --- Oleg Kobchenko <[EMAIL PROTECTED]> wrote:
> > > >
> > > > > How about variation on the theme
> > > > >
> > > > >    >./\ 3 4 0 0 5 0 6 0 0 0 7
> > > > > 3 4 4 4 5 5 6 6 6 6 7
> > > > >
> > > > >
> > > > > --- Dan Bron <[EMAIL PROTECTED]> wrote:
> > > > >
> > > > > > Raul wrote:
> > > > > > >    drag=: {~ [EMAIL PROTECTED] >./\@:* ([EMAIL PROTECTED] 1{.0{.])
> > > > > >
> > > > > > Thank you; this is indeed faster;  I've replaced my definition
> > with
> > > > > > yours.  However, I was hoping for a solution that would complete
> > in
> > > > > > about half the time of the solutions I provided.  That is, I'd
> > like a
> > > > > > 2x or 100% speedup;  drag  is only about 20% faster than  drag0
> > on my
> > > > > > dataset.
> > > > > >
> > > > > > Any other lines of attack?
> > > > > >
> > > > > > -Dan
> > 
> > 
> > 
> > 
> > __________________________________________________________________________
> > __________
> > Need a quick answer? Get one in minutes from people who know.
> > Ask your question on www.Answers.yahoo.com
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> 
> 
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
> 



 
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