I did not mention this example previously as I thought you were
seeking more non-trivial examples, but I find this useful...
(}. - }:) NB. Difference function of adjacent
elements in a vector
(}. - }:)^:n NB. nth order difference function (ie 2nd
differences, 3rd differences etc)
(}.-}:)^:(i.4) 3 5 8 8 9 12 14
3 5 8 8 9 12 14
2 3 0 1 3 2 0
1 _3 1 2 _1 0 0
_4 4 1 _3 0 0 0
.../Rob Hodgkinson
On 04/02/2009, at 12:09 AM, John Randall wrote:
> Thanks to all, especially Roger, for the dyadic fork examples.
>
> I regard the tautologies as a bit meta, but I do like >. - <. . I
> had a
> more complicated example along the same lines.
>
> Before posing the question, I followed Oleg's advice in that I
> eyeballed
> the dyads in J Phrases: almost all use [ ] @ @: or constant functions.
>
> Best wishes,
>
> John
>
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