The problem occurs in the Windows GUI with the 'windows()' graphics device.
In the following example the red diagonal line appears in 3 plots but not
in the one
with xpd=TRUE and alpha.f=0.9.
> par(mfrow=c(2,2))
> for(xpd in c(FALSE, TRUE)) for(alpha.f in c(.9, 1))
plot(0:1,xpd=xpd,type="l",col=ad
> On Apr 16, 2018, at 10:41 AM, Jiaxuan Chen
> wrote:
>
> Dear R-devel,
>
> I think I've found a bug - the alpha transparency doesn't work when plotting
> lines with xpd = TRUE.
>
> #works
> plot(1:20, col="#1874CD", xpd=T, type="l")
>
> #works
> plot(1:20, col="#1874CD50", xpd=F, type="l")
