The Vector front page says that the Dyalog function
{(+/omega)divide rho omega}
is the same as the J tacit verb
(+/%#)
They are not the same. One difference comes from
the difference between # and rho; another difference
is between +/ in J and +/ in APL (+/ in J is + slashbar
in APL); another is the difference in the way they are
used in operator expressions. (e.g. (+/%#)"r a).
Can someone with access to Dyalog APL tell me
what the following does? (index origin 0)
a {is} ? 3 5 7 {rho} 100
{(+/omega) divide rho omega} a
{(+/omega) divide rho omega}[0] a
{(+/omega) divide rho omega}[1] a
{(+/omega) divide rho omega}[2] a
----- Original Message -----
From: Dan Bron <[EMAIL PROTECTED]>
Date: Thursday, October 25, 2007 13:26
Subject: Re: [Jprogramming] Puzzle from "The Early Years"
To: Programming forum <[email protected]>
> Roger posed:
> > What is the shortest expression you know of for
> computing
> > the average of a vector v? (Shortest = fewest
> words.)
>
> Someone at Vector may've been reminiscing about the same
> puzzle; check out the APL and J examples in the big yellow
> box at the top of their front page:
>
> http://www.vector.org.uk/
>
> > The J answer is shorter than the APL answer.
>
> This is due to the verb train innovation; i.e. tacit code.
> The sole difference is that APL must name the vector twice.
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