\HeaderA{roman}{Roman Numerals}{roman}
\aliasA{as.roman}{roman}{as.roman}
\keyword{arith}{roman}
\begin{Description}\relax
Manipulate integers as roman numerals.
\end{Description}
\begin{Usage}
\begin{verbatim}
as.roman(x)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] a numeric vector, or a character vector of arabic or roman
numerals.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
\code{as.roman} creates objects of class \code{"roman"} which are
internally represented as integers, and have suitable methods for
printing, formatting, subsetting, and coercion to \code{character}.

Only numbers between 1 and 3899 have a unique representation as roman
numbers.
\end{Details}
\begin{References}\relax
Wikipedia contributors (2006). Roman numerals.
Wikipedia, The Free Encyclopedia.
\url{http://en.wikipedia.org/w/index.php?title=Roman_numerals\&oldid=78252134}.
Accessed September 29, 2006.
\end{References}
\begin{Examples}
\begin{ExampleCode}
## First five roman 'numbers'.
(y <- as.roman(1 : 5))
## Middle one.
y[3]
## Current year as a roman number.
(y <- as.roman(format(Sys.Date(), "%Y")))
## 10 years ago ...
y - 10
\end{ExampleCode}
\end{Examples}

