\begin{Schunk}
\begin{Sinput}
 names(x4a)
\end{Sinput}
\begin{Soutput}
[1] "a" "b" "c"
\end{Soutput}
\begin{Sinput}
 names(x4a) <- c("Joe", "Bill", "Henry")
 x4a
\end{Sinput}
\begin{Soutput}
  Joe  Bill Henry 
  1.0   3.0   9.1 
\end{Soutput}
\end{Schunk}
