Using the a) option in Raul's reply -
L =. > @: {. @: [ NB. use the "x" value from list
R =. > @: {: @: [ NB. use the "y" value from list
xy =. ; NB. x and y into a list. [[Only
if y is not boxed]]
xy =. ,&:< NB. x and y into a list.
fn =. xy ((L a ]) c (R d ])) b NB. x & y combined, factor out
b-replace with ]
Ian
Ian Shannon
Landscape Modelling and Decision Support Section
Department of Environment, Climate Change & Water (NSW)
email: Ian.Shannon () environment.nsw.gov.au
Date: Tue, 28 Sep 2010 16:56:46 -0400
From: Raul Miller <rauldmil...@gmail.com>
Subject: Re: [Jprogramming] An Abbreviation
To: Programming forum <programming@jsoftware.com>
Message-ID:
<aanlktim=d+a6d9gx8wq8l8aohor2fy0nq_52hfahg...@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
On Tue, Sep 28, 2010 at 4:50 PM, Justin Paston-Cooper
<paston.coo...@gmail.com> wrote:
> Is there an abbreviation for the following fork? I don't want the
> computation of <<x b y>> to happen twice.
>
> ([ a b) c (] d b)
When you need to intermix three (or more) values in J,
you have several options:
[1] Compose some (or all) of them into a list
[2] Use an explicit definition
[3] recompute some of them
Each has its own advantages and disadvantages.
--
Raul
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