If you need more accuracy do

   (i.9) (p.~ pol) (,: i...@#)0 1 4x
0 1 4 9 16 25 36 49 64


R.E. Boss


> -----Oorspronkelijk bericht-----
> Van: [email protected] [mailto:programming-
> [email protected]] Namens Raul Miller
> Verzonden: vrijdag 11 juni 2010 4:30
> Aan: Programming forum
> Onderwerp: Re: [Jprogramming] Polynomial extrapolation
> 
> On Thu, Jun 10, 2010 at 4:06 PM, R.E. Boss <[email protected]> wrote:
> > The first problem, extrapolating a polynomial (of degree k) through k
> > points, can be done as follows.
> >
> >    pol=: (+/ . *~[: %.@:|: (^"_ 0 (i...@#)))/
> ...
> > This extrapolating is much more efficient.
> 
> However, it is not necessarily as accurate:
> 
>     (i.9) (p.~ pol) (,: i...@#)0 1 4
> 1.27676e_15 1 4 9 16 25 36 49 64
> 
> (Using differences, the first element of the result would be zero.)
> 
> --
> Raul
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm

----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to