Add lines to an existing plot of an object of class jointdata, for a longitudinal variable. It is possible to plot all the subjects in the data set, or just a selected subset. See subset.jointdata.
## S3 method for class 'jointdata'lines(x, Y.col,...)
Arguments
x: object of class jointdata.
Y.col: column number, or column name, of longitudinal variable to be plotted. Defaults to Y.col = NA, plotting all longitudinal variables.
...: other graphical arguments; see plot.
Returns
A graphical device with a plot for longitudinal data.