Sorry for reporting this too generally.  I will narrow down the issue.  It may 
be related to number of parameters in x, or more likely to the length of the 
verb definition, or possibly whether it calls other bivalent definitions.  Will 
clarify later.


________________________________
 From: Devon McCormick <[email protected]>
To: J-programming forum <[email protected]> 
Sent: Saturday, August 24, 2013 12:45:27 PM
Subject: Re: [Jprogramming] a performance quirk - bivalent verbs
 

If I understand correctly what you're saying, I don't find this to be true,
at least for this simple example.

   vv=: 3 : 0
   1 vv y
:
   x*%.y%x
)

   mm=. ([: <: [: +: 0 ?@$~ ])&.>2$&.>10+i.100  NB. 100 arguments

   (10) 6!:2 'vv&.>mm'
0.288892
   (10) 6!:2 '1 vv&.>mm'
0.295604
   (10) 6!:2 '10 vv&.>mm'
0.293436

These timings look virtually identical.


On Fri, Aug 23, 2013 at 9:11 PM, bill lam <[email protected]> wrote:

> Can you give a detail account of how you tested the performance?
>
> Пт, 23 авг 2013, Pascal Jasmin писал(а):
> >
> >
> > apologies if this issue is well known,
> >
> > If you use a bivalent verb definition such as
> >
> > v =: 3 : 0
> > (default; params) v y NB. just delegates to dyadic implementation
> > :
> > dyadic implementation
> > )
> >
> > then calling it monadically is 1000x+ slower than calling it dyadically,
> or by changing the definition to:
> >
> > v =: 3 : '(default; params) v y'
> > vD =: 4 : 0
> > dyadic implementation
> > )
> >
> >
> > Is there some other workaround for the monadic definition that doesn't
> affect performance?
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
> --
> regards,
> ====================================================
> GPG key 1024D/4434BAB3 2008-08-24
> gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>



-- 
Devon McCormick, CFA
^me^ at acm.
org is my
preferred e-mail
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