On Thu, 2006-05-25 at 09:26 -0700, Peter Lauren wrote: > I was wondering what would be the best way to put a > vertical line on a graph made with plot(). I can get > an horizontal line by plotting a vector where every > element has the same value but it is not as clear how > a vertical line should be done. > > Thanks very much, > Peter.
Is this what you want? set.seed(12345) # reproducible random numbers datx <- rnorm(100) # some example data daty <- rnorm(100) plot(datx, daty) # plot it abline(v = mean(datx)) # add vertical line at mean of x abline(v = 0.5, col = "red") # same but at x == 0.5 abline(h = mean(daty)) # horizontal lines abline(a = 0, b = 1) # lines of arbitrary intercept and slope see ?abline HTH G -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% * Note new Address, Telephone & Fax numbers from 6th April 2006 * %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Gavin Simpson ECRC & ENSIS [t] +44 (0)20 7679 0522 UCL Department of Geography [f] +44 (0)20 7679 0565 Pearson Building [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street [w] http://www.ucl.ac.uk/~ucfagls/cv/ London, UK. [w] http://www.ucl.ac.uk/~ucfagls/ WC1E 6BT. %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
