On Thu, 7 Oct 2004 [EMAIL PROTECTED] wrote:
> The release notes for R 2.0.0 states:
Would that be the NEWS file? R does not have `release notes' per se.
> It is now possible to specify colours with a full alpha
> transparency channel via the new 'alpha' argument to the
> rgb() and hsv() functions, or as a string of the form "#RRGGBBAA".
>
> NOTE: most devices draw nothing if a colour is not opaque,
> but PDF and Quartz devices will render semitransparent colours.
>
> A new argument 'alpha' to the function col2rgb()
> provides the ability to return the alpha component of
> colours (as well as the red, green, and blue components).
>
> I'm using R 2.0.0 on Windows 2000 and wanted to try this feature. The
> following simple test works fine:
>
> pdf("c:/alpha.pdf")
> plot(rnorm(1:100),rnorm(1:100),col="#000055ff",pch=16)
> dev.off()
>
> But as soon as I change alpha value from "ff" to "fe", the points are no
> longer visible for me. I've tried viewing the pdf with Acrobat Reader
> 5.1.0 and gsview4.5.
>
> Do I need a more recent pdf viewer? Is this feature not working on
> Windows? Am I doing something wrong? Any tips would be appreciated.
As so often happens, the `something wrong' is not reading the help file.
As the NEWS file _also_ says
o A 'version' argument has been added to pdf() device. If this is
set to "1.4", the device will support transparent colours.
pdf("alpha.pdf", version="1.4") should work for you: it does for me.
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
[EMAIL PROTECTED] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
