;<@(*{.)\.>:i.5
1 2 3 4 5 4 6 8 10 9 12 15 16 20 25
~.,*/~>:i.5
1 2 3 4 5 6 8 10 9 12 15 16 20 25
R.E. Boss
> -----Oorspronkelijk bericht-----
> Van: programming-boun...@jsoftware.com
> [mailto:programming-boun...@jsoftware.com] Namens Raul Miller
> Verzonden: maandag 25 juni 2012 18:51
> Aan: Programming forum
> Onderwerp: Re: [Jprogramming] Multiplying with folds
>
> Why do you want this?
>
> If it's efficiency, note that the size of the dense array */~N is
> typically less than the size of a linked list which only represents
> the products of unique combinations of pairs (if we assume that linked
> list pointer size is approximately the same size as a number), and
> also note that typical cpu cache implementation heavily favors regular
> operations.
>
> If it's because you need unique values, you might consider using:
>
> ~.,*/N
>
> If it's for some other purpose, the topic might have inherent interest...
>
> Thanks,
>
> --
> Raul
>
> On Mon, Jun 25, 2012 at 12:37 PM, David Vaughan <purpleblue...@gmail.com>
> wrote:
> > I'm looking for a verb to achieve the same thing as just the unique items
> > of */~ N, i.e. n0*(n0 ... nk) n1*(n1 ... nk) n2*(n2 ... nk) ... nk*nk.
> >
> > I can easily create the result, but I want to be able to calculate it more
> > efficiently, without having to do the multiplications that will ultimately
> > be redundant (which would be ~.,*/~ N).
> >
> > I'm not particularly good with folds and similar concepts, so I expect the
> > solution is relatively simple. Can anyone help?
> >
> > Many thanks.
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