Re: [Jprogramming] inverse permutation vector

[Raul Miller]

On 9/8/07, bill lam <[EMAIL PROTECTED]> wrote:
> Hello, I want to find the inverse permutation vector, eg
>    ]pv=. /:a=. 10 13 14 10 15 12
> 0 3 5 1 2 4
>    pv{a
> 10 10 12 13 14 15
>
> how to get ipv from pv such that
>    ipv{pv{a   give back   a

ipv=: /:inv pv
or
ipv=: /: pv

(same thing, though /:inv does not display that way).

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