> rf <- pull.rf(mapc)
> lod <- pull.rf(mapc, what="lod")
> mn4 <- markernames(mapc, chr=4)
> par(mfrow=c(2,1))
> plot(rf, mn4[3], bandcol="gray70", ylim=c(0,1), alternate.chrid=TRUE)
Error in plot.new() : figure margins too large