Plot whether a participant was disease or not as points on top of the vitamin D curves plotted from plot.vitd.curve.
infection.count.plot( expos, infect, pch = 20, cex = 1.5, col = "red" )
An object of class exposure.levels.
An object of class infection.count.
Plotting symbol for the points.
Standard graphical parameter.
Colour of the plotted points.
Rebecca Mangan and Jason Wyse