\Header{proc.time}{Running Time of R}
\keyword{utilities}{proc.time}
\begin{Description}\relax
\code{proc.time} determines how much time (in seconds) the currently
running \R{} process already consumed.\end{Description}
\begin{Usage}
\begin{verbatim}
proc.time()
\end{verbatim}
\end{Usage}
\begin{Value}
A numeric vector of length 5, containing the user, system, and total
elapsed times for the currently running \R{} process, and the cumulative
sum of user and system times of any child processes spawned by it.

The resolution of the times will be system-specific; it is common for
them to be recorded to of the order of 1/100 second, and elapsed
time is rounded to the nearest 1/100.

It is most useful for ``timing'' the evaluation of \R{} expressions,
which can be done conveniently with \code{\Link{system.time}}.\end{Value}
\begin{Note}\relax
It is possible to compile \R{} without support for \code{proc.time},
when the function will not exist.\end{Note}
\begin{SeeAlso}\relax
\code{\Link{system.time}} for timing a valid \R{} expression.\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
ptm <- proc.time()
for (i in 1:50) mad(runif(500))
proc.time() - ptm
\end{ExampleCode}
\end{Examples}

