\HeaderA{plot.acf}{Plot Autocovariance and Autocorrelation Functions}{plot.acf}
\keyword{hplot}{plot.acf}
\keyword{ts}{plot.acf}
\begin{Description}\relax
Plot method for objects of class \code{"acf"}.
\end{Description}
\begin{Usage}
\begin{verbatim}
## S3 method for class 'acf':
plot(x, ci = 0.95, type = "h", xlab = "Lag", ylab = NULL,
     ylim = NULL, main = NULL,
     ci.col = "blue", ci.type = c("white", "ma"),
     max.mfrow = 6, ask = Npgs > 1 && dev.interactive(),
     mar = if(nser > 2) c(3,2,2,0.8) else par("mar"),
     oma = if(nser > 2) c(1,1.2,1,1) else par("oma"),
     mgp = if(nser > 2) c(1.5,0.6,0) else par("mgp"),
     xpd = par("xpd"),
     cex.main = if(nser > 2) 1 else par("cex.main"),
     verbose = getOption("verbose"),
     ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] an object of class \code{"acf"}.
\item[\code{ci}] coverage probability for confidence interval.  Plotting of
the confidence interval is suppressed if \code{ci} is zero or
negative.
\item[\code{type}] the type of plot to be drawn, default to histogram like
vertical lines.
\item[\code{xlab}] the x label of the plot.
\item[\code{ylab}] the y label of the plot.
\item[\code{ylim}] numeric of length 2 giving the y limits for the plot.
\item[\code{main}] overall title for the plot.
\item[\code{ci.col}] colour to plot the confidence interval lines.
\item[\code{ci.type}] should the confidence limits assume a white noise
input or for lag \eqn{k}{} an MA(\eqn{k-1}{}) input?
\item[\code{max.mfrow}] positive integer; for multivariate \code{x}
indicating how many rows and columns of plots should be put on one
page, using \code{\LinkA{par}{par}(mfrow = c(m,m))}.
\item[\code{ask}] logical; if \code{TRUE}, the user is asked before a new
page is started.
\item[\code{mar, oma, mgp, xpd, cex.main}] graphics parameters as in
\code{\LinkA{par}{par}(*)}, by default adjusted to use smaller than
default margins for multivariate \code{x} only.

\item[\code{verbose}] logical.  Should \R{} report extra information on
progress?
\item[\code{...}] graphics parameters to be passed to the plotting
routines.
\end{ldescription}
\end{Arguments}
\begin{Note}\relax
The confidence interval plotted in \code{plot.acf} is based on an
\emph{uncorrelated} series and should be treated with appropriate
caution.  Using \code{ci.type = "ma"} may be less potentially
misleading.
\end{Note}
\begin{SeeAlso}\relax
\code{\LinkA{acf}{acf}} which calls \code{plot.acf} by default.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
require(graphics)

z4  <- ts(matrix(rnorm(400), 100, 4), start=c(1961, 1), frequency=12)
z7  <- ts(matrix(rnorm(700), 100, 7), start=c(1961, 1), frequency=12)
acf(z4)
acf(z7, max.mfrow = 7)# squeeze on 1 page
acf(z7) # multi-page
\end{ExampleCode}
\end{Examples}

