Specifying relative position of text in a plot
On Thu, 13 Mar 2008, Tom La Bone wrote:
Thanks for all of the suggestions. The key key here seems to be using the
"par" function to change the coordinate system like so
plot(rnorm(100), rnorm(100))
op <- par("usr")
par(usr = c(0, 1, 0, 1))
text(0.5,0.5,"TEST")
par(usr = op)
Prof Ripley commented that this approach will also work on log plots, but I
don't think I completely understand what is going on because this does not
work for me
plot(rlnorm(100), rlnorm(100),log="xy")
op <- par("usr")
par(usr = c(0, 1, 0, 1))
text(0.5,0.5,"TEST")
par(usr = op)
Any hints on what I am doing wrong with the log plots? Thanks again for the
help.
You need par(usr = c(0, 1, 0, 1), xlog=FALSE, ylog=FALSE) to set up a non-log coordinate system.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595