\Header{ARMAtoMA}{Convert ARMA Process to Infinite MA Process}
\keyword{ts}{ARMAtoMA}
\begin{Description}\relax
Convert ARMA process to infinite MA process.
\end{Description}
\begin{Usage}
\begin{verbatim}
ARMAtoMA(ar = numeric(0), ma = numeric(0), lag.max)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{ar}] numeric vector of AR coefficients
\item[\code{ma}] numeric vector of MA coefficients
\item[\code{lag.max}] Largest MA(Inf) coefficient required.
\end{ldescription}
\end{Arguments}
\begin{Value}
A vector of coefficients.
\end{Value}
\begin{References}\relax
Brockwell, P. J. and Davis, R. A. (1991) \emph{Time Series: Theory and
Methods}, Second Edition.  Springer.
\end{References}
\begin{SeeAlso}\relax
\code{\Link{arima}}, \code{\Link{ARMAacf}}.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
ARMAtoMA(c(1.0, -0.25), 1.0, 10)
## Example from Brockwell & Davis (1991, p.92)
## answer (1 + 3*n)*2^(-n)
n <- 1:10; (1 + 3*n)*2^(-n)
\end{ExampleCode}
\end{Examples}

