I had thought the notion I had for pnm:
(}: (^ * ^~) }.)@(p:@x:@i.)
would be slower than prh:
2 */@(^ |.)\ p:@x:@i.
But they turn out not very different:
(100) 6!:2 'prh 40'
0.00277307
(100) 6!:2 'pnm 40'
0.00263127
9!:14 ''
j701/2011-01-10/11:25 build: Feb 6 2011 16:16:29
On 2014.10.17 16:48:30, I said,
> If one can take 2 3 5 and 3 5 7 as given, this might do:
>
> */2 3 5x (^ ,: ^~) 3 5 7x
>
> If it was "do this for the first N primes", it would be
> a little more complicated.
>
>
> On 2014.10.17 18:30:14, you,
> the extraordinary Kip Murray, spake thus:
>
> >
> > 72 30375 1313046875
> >
> > The first of these numbers is (2^3) * (3^2) , the second is (3^5) * (5^3),
> > and the third is (5^7) * (7^5) . You see the pattern involving successive
> > primes.
> >
> > Write a J expression to produce the above list. --Kip Murray
> >
--
Nollaig MacKenzie
http://www.yorku.ca/nollaig
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