\begin{Schunk}
\begin{Sinput}
 plot(salary~age , data=mydf, type="n", xlab="Age (years)", ylab="Hourly Wage (US)")
 myColors <- ifelse(mydf$sex == "M", "green", "red")  ##alternating red and green
 # with(mydf,  text( age, salary, labels = subjects, col = myColors))
 text(salary ~ age, data = mydf, labels = subjects, col = myColors)
\end{Sinput}
\end{Schunk}
