Like this: segments(x0=c(5.0,5.5,6), y0=c(0,0,0), x1=c(5.0,5.5,6), y1=c(0.12,0.60,0.20))
If you wanted them to extend the entire height of the plot, abline(v=c(5.0,5.5,6)) is simpler. Thanks for the reproducible example, Sarah On Mon, Mar 11, 2013 at 10:10 AM, Naser Jamil <jamilnase...@gmail.com> wrote: > Dear All, > May I seek your suggestion on a simple issue. I want to draw vertical lines > at some positions in the following R plot. To be more specific, I wish to > draw vertical lines at d=c(5.0,5.5,6) and they should go till > p=c(0.12,0.60,0.20) . I haven't found any way out, though made several > attempts. Please run the following commands first if you are interested in! > > ####################################################### > > psi1<-function(alpha1,beta1,alpha2,beta2,d){ > exp(alpha1+beta1*d)/((1+exp(alpha1+beta1*d))*(1+exp(alpha2+beta2*d))) > } > alpha1<--3.5 > beta1<-1 > alpha2<--6 > beta2<-0.72 > > d<-seq(0.5,10,0.01) > plot(d,psi1(alpha1,beta1,alpha2,beta2,d),type="l",pch=18, ylim=c(0,1), > xlab="Dose", ylab="Probabilitty") > > ########################################################## > > > Many thanks for the help! > > Regards, > Jamil. > -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.