Hi, I'm trying to construct what I think should be a fairly simple plot, yet I'm having a tremendously difficult time. I'm trying to create a very simple graph showing the effect of interest rates on option prices. I have three sets of option prices that I've calculated using rMetrics. Each set contains a call price and a put price at a particular interest rate. Each set uses a different interest rate(0%, 5%,10%). The idea is to have "call" and "put" on the X axis, the option prices on Y, and to have three lines drawn from the call price to the put price to show how the option price varies relative to interest rates. Kind of a see-saw like graph. I need to keep this simple because this is meant to teach the absolute basics about the effects of interest rates on option prices. These are the option prices I'm using: CallPrice1<-CRRBinomialTreeOption(TypeFlag="ca",S=20, X=20, Time=1/12, r=0.0, b=0.0, sigma=.4, n=100)@price CallPrice2<-CRRBinomialTreeOption(TypeFlag="ca",S=20, X=20, Time=1/12, r=.05, b=.05, sigma=.4, n=100)@price CallPrice3<-CRRBinomialTreeOption(TypeFlag="ca",S=20, X=20, Time=1/12, r=.10, b=.10, sigma=.4, n=100)@price PutPrice1<-CRRBinomialTreeOption(TypeFlag="pa",S=20, X=20, Time=1/12, r=0.0, b=0.0, sigma=.4, n=100)@price PutPrice2<-CRRBinomialTreeOption(TypeFlag="pa",S=20, X=20, Time=1/12, r=.05, b=.05, sigma=.4, n=100)@price PutPrice3<-CRRBinomialTreeOption(TypeFlag="pa",S=20, X=20, Time=1/12, r=.10, b=.10, sigma=.4, n=100)@price L1<-c(CallPrice1, PutPrice1) L2<-c(CallPrice2, PutPrice2) L3<-c(CallPrice3, PutPrice3) Everything I've tried as basically failed. So far I've only been able to plot one of the lines. And this is as far as I've gotten in trying to plot this: plot(1:2, L1, type="b", main="Option Prices", xlab="Calls and Puts", ylab="Option Price", lwd=3, col="dark red") But obviously this makes the X axis 1:2 rather than "Calls" and "Puts", also, I've been completely unsuccessful in adding the L2 and L3 lines. Any help and suggestions would be greatly appreciated. Thanks. James