[R] graphics - joining repeated measures with a line

[hadley wickham]

> I would like to join repeated measures for patients across two visits using
> a line. The program below uses symbols to represent each patient. Basically,
> I would like to join each pair of symbols.

This is easy in ggplot:

install.packages("ggplot")
library(ggplot)

qplot(visit, var, id=patient, type=c("line", "point"), colour=factor(patient))

Regards,

Hadley