\Header{sign}{Sign Function}
\keyword{arith}{sign}
\begin{Usage}
\begin{verbatim}
sign(x)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\texttt{x}] a numeric vector
\end{ldescription}
\end{Arguments}
\begin{Description}
\texttt{sign} returns a vector with the signs of the corresponding
elements of \texttt{x} (the sign of a real number is 1, 0, or \eqn{-1}{}
if the number is positive, zero, or negative, respectively).

Note that \texttt{sign} does not operate on complex vectors.\end{Description}
\begin{SeeAlso}
\texttt{\Link{abs}}\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
sign(pi) # == 1
sign(-2:3)# -1 -1 0 1 1 1
\end{ExampleCode}
\end{Examples}

