points.jointdata function

Add points to an existing jointdata plot

Add points to an existing plot of an object of class jointdata, for a longitudinal variable. It is possible plot all the subjects in the data set, or just a selected subset. See subset.jointdata.

## S3 method for class 'jointdata'
points(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. Other functions are useful to be used with this as plot and lines.

Examples

data(heart.valve)
heart.surv <- UniqueVariables(heart.valve,
                              var.col = c("fuyrs", "status"),
                              id.col = "num")
heart.long <- heart.valve[, c(1, 4, 5, 7, 8, 9, 10, 11)]
heart.jd <- jointdata(longitudinal = heart.long,
                      survival = heart.surv,
                      id.col = "num",
                      time.col = "time")
                      
# Randomly select a pair of subjects to plot profiles of
take <- sample(1 : max(heart.jd$survival$num), 2)
heart.jd.1 <- subset(heart.jd, take[1])
heart.jd.2 <- subset(heart.jd, take[2])

plot(heart.jd.1, Y.col = "grad", type = "p")
points(heart.jd.2, Y.col = "grad", col = "blue", pch = 20)

Author(s)

Ines Sousa