[R] plot with pairwise joined points

[William Simpson]

I would like to do as follows
plot(a,b)
points(c,d,pch=19)

Now join with a line segment point a[1], b[1] to c[1], d[1]; a[2],
b[2] to c[2], d[2] ... a[n], b[n] to c[n], d[n]

All corresponding points from the two data sets are joined by line segments.

Thanks very much for any tips on how to do this.

Bill