From p.murrell at auckland.ac.nz  Wed Dec  5 20:23:05 2007
From: p.murrell at auckland.ac.nz (Paul Murrell)
Date: Thu, 06 Dec 2007 08:23:05 +1300
Subject: [Rd] [R] color palette from red to blue passing white (shifted
 from R-help)
In-Reply-To: <18262.23325.226710.391865@stat.math.ethz.ch>
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	<18262.23325.226710.391865@stat.math.ethz.ch>
Message-ID: <4756FA99.8010505@stat.auckland.ac.nz>

Hi


Martin Maechler wrote:
>>>>>> "Paul" == Paul Murrell <p.murrell at auckland.ac.nz>
>>>>>>     on Wed, 05 Dec 2007 08:53:10 +1300 writes:
> 
>     Paul> Hi
>     Paul> Achim and I have been looking at tidying up the colorspace package (see
>     Paul> http://r-forge.r-project.org/projects/colorspace/) to fix a few
>     Paul> inaccuracies, PLUS the possibility of declaring R's internal color space
>     Paul> to be sRGB.
> 
>     Paul> I have started an RFC on the r-developer site
>     Paul> (http://developer.r-project.org/sRGB-RFC.html) to discuss some possible
>     Paul> changes to the core engine and add-on packages.
> 
>     Paul> One of the issues will be consolidating some of the double-ups (e.g.,
>     Paul> hcl() in base and the counterpart in package 'colorspace';  I did not
>     Paul> even know about convertColor()!).
> 
>     Paul> Ideally, we would have only one copy of the conversions between the
>     Paul> various colorspaces (probably C code, then the various R-level front
>     Paul> ends can all just run off the same internal code).
> 
>     Paul> A lot of these conversions exist now in 'colorspace', but as Thomas
>     Paul> pointed out, the S4-ness of 'colorspace' is a problem for making these
>     Paul> conversions part of base R.
> 
> Hmm, I think we are currently only required to keep 'base' not
> dependent on 'methods'.
> Why should 'grDevices' or new "standard R" package not be
> dependent on 'methods' ?
> Many of us would like to see S4 been used much more widely.


Great.  I will keep working on the RFC to see if I can propose a way to
reconcile all of the color-conversion and palette-selection code based
on a single sRGB representation in the R core and only one set of
conversion functions.

Paul


> Martin

-- 
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
paul at stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/



[Rd] [R] color palette from red to blue passing white (shifted from R-help)
Paul Murrell