xyplot and abline
On Sat, 17 Sep 2005, Marc Bernard wrote:
Dear All, I wonderif there is a simple way to draw a regression line in the xyplot: more specifically, let: age <- c(20:30, 31:40 ) age.cut <- cut(age, breaks = 2 ) y<- rnorm(20) x <- rnorm(20,4,1) xyplot(y ~ x| age.cut, xlab="x", ylab="y") How to draw (in the plot given by xyplot) the two regression lines (y ~ x) corresponding to the two category of age.cut ?
Use a panel function and call panel.lmline from it. Something like
mypanel <- function (x, y, ...)
{
panel.xyplot(x,y, ...)
panel.lmline(x,y, ...)
}
xyplot(y ~ x| age.cut, xlab="x", ylab="y", panel=mypanel)
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