[R] Plotting lines and points on the second plot when using gap.plot in plotrix

[michael watson (IAH-C)]

Hi

My question is simple - the gap.plot function in the plotrix package
allows users to draw graphs that have a broken axis.  However, I want to
then add a line to the "second" plot, but can't.

Eg:

twogrp<-c(rnorm(10)+4,rnorm(10)+20)
gap.plot(twogrp,rnorm(20),gap.bounds=c(8,16),gap.axis="x",xlab="X
values",
       xtics=c(4,7,17,20),ylab="Y values",main="Plot gap on X axis") 

# this doesn't work
points(17,0,col="red")

# this does work
points(4,0,col="green")

I somehow need to set the focus to the second plot so that I can draw
lines and points on it.

Any help?

Mick