something like this points(zz[1:length(obs$value)], obs$value,lty=3,lwd=1,col="red",pch=19) Sent from my iPhone > On Jun 2, 2016, at 11:36, Thomas Adams <tea3rd at gmail.com> wrote: > > points(zz, obs$value,lty=3,lwd=1,col="red",pch=19)