[Rd] readPNG gives warnings and doesn't execute sample code from help files

Ben Bolker bbolker at gmail.com
Tue Feb 15 14:20:59 CET 2011

Joris Meys <jorismeys <at> gmail.com> writes:

> I believed the standard plotting device on R in 2.12.1 would support
> per-pixel alpha. It does support alpha, as
>  plot(1:2,type="l")
>  polygon(c(1,1,2,2),c(1,2,2,1),col=rgb(60,100,60,60,maxColorValue=255))
> plots correctly. Which device should I use then?



(near the bottom of the page, where it explains that the
Windows device supports alpha but not per-pixel alpha ...)

    Ben Bolker

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