[R-sig-Geo] semi-transparent layer with image()

[hadley wickham]

There's the alpha function in the ggplot2 package:

plot(1:90, 1:90, pch=16, cex=2, col="red")
points(1:90, 1:90, pch=16, cex=2, col=alpha(grey(90:1/90), 0.5))

Hadley

On 11/16/07, Ingo Holz <Ingo.Holz at uni-hohenheim.de> wrote:
> Hi,
>
>  is there an easier way to get a semi-transparent grey-palette?
>
>  plot(1:90, 1:90, pch=16, cex=2, col="red")
>  points(1:90, 1:90, pch=16, cex=2, col=rgb(t(col2rgb(grey(90:1/90))),
> alpha=100, maxColorValue=255))
>
>  windows() does support semi-transparent colours
>
> Thanks,
> Ingo
>
>         [[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>


-- 
http://had.co.nz/