I am using ggplot2 on ubuntu 12.04. By default my x11 type is set to Xlib. So when I use a smoother in qplot, I get an error like:
\"semi-transparency is not support
Define another function 'x11' which sets the proper type:
x11 = function (...) grDevices::x11(...,type='cairo')
To make this permanent, you could add the following lines to your ~/.Rprofile file:
setHook(packageEvent("grDevices", "onLoad"),
function(...) grDevices::X11.options(type='cairo'))
options(device='x11')