I think this is what you are getting at. Hope this helps.
#index data to determine what low and high levels of tvHrs are (I said anything over 15 hours is considered 'high') index=which(tvHrs > 15) #Plot the first plot, which is the 'high', only using values from crimeDvp that are in 'index' (corresponding to high levels of tvHrs plot(prop.table(table(crimeDvp[index])),type='b',ylab='percent',xlab='crime dev',col='red') lines(prop.table(table(crimeDvp[-index])),type='b', col='black') lines(prop.table(table(crimeDvp)),type='b',col='green') legend("topright", inset=.05, title="TV consume", c("high","low","all"), fill=c('red','black','green')) -- View this message in context: http://r.789695.n4.nabble.com/Multiple-line-plot-tp4394539p4395262.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.