library(plotrix)  
date<-1:31  
ly<-5:35  
ry<-11:41  
twoord.plot(date,ly,date,ry,xlim=c(0,32),lylim=c(1,40),rylim=c(0,50), lcol=4,rcol=2,xlab="date",ylab="ly",rylab="ry",type=c("b","b"))